process for generating a dental preparation guide

专利摘要:
DENTAL PREPARATION GUIDE A process to generate a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, the process comprising: a: obtaining a 3D digital representation of a set of pre teeth -prepared; b: virtually removing said at least one tooth from the digital 3D representation of a set of pre-prepared teeth, so that a digital 3D representation of a remaining set of teeth is formed; c: providing a desired virtual dental restoration expressing a desired shape of the dental restoration; d: create a virtual validation surface for the dental preparation guide based on the desired virtual dental restoration, where the validation surface is such that the tooth preparation can be validated by the dental preparation guide; and e: create a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining set of teeth.
公开号:BR112014012813B1
申请号:R112014012813-8
申请日:2012-11-26
公开日:2021-02-02
发明作者:Rune Fisker；Nikolaj Deichmann
申请人:3Shape A/S；
IPC主号:

专利说明:

[0001] The present invention relates, in general, to a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration. More particularly, the invention relates to a process for generating the dental preparation guide, a process for using that dental preparation guide, and a user interface and system for designing and using that dental preparation guide.
[0002] When a patient's tooth is sick or dead, it is often recommended that part of the tooth be removed and replaced with a dental restoration, such as a crown restoration, which can restore the mechanical strength and aesthetic appearance of the tooth . In other cases, the tooth is diseased or broken, so it cannot withstand a dental restoration and needs to be completely extracted. In such cases, the dental restoration can be a bridge restoration, with a pontic, which is designed to replace the diseased or broken tooth, and two crowns surrounding the pontic. The neighboring teeth are then prepared for the crowns of the dental restoration.
[0003] Both when preparing a single tooth for a dental restoration, when preparing neighboring teeth for the crowns of a bridge, the dentist scrapes off part of the tooth material to form one or more prepared teeth, which can accept dental restoration. The material that is removed makes room for the dental restoration, so that when the dental restoration is placed in the patient's mouth, the restored tooth or teeth may be the same shape or size as before preparation.
[0004] The desired form of dental restoration is sometimes known when the dentist begins to prepare teeth, and this knowledge can be used to create a dental preparation guide, which the dentist can use to guide tooth preparation.
[0005] In some prior art processes for the manufacture of dental preparation guides, the validation surface is defined by a physical model of teeth, such as a plaster model, worked to be in good shape and size and to leave a space for insertion of the dental restoration in the prepared tooth. The imprecision in the production of this physical model of teeth will result in an imprecision in the form of the dental preparation guide and, therefore, in the form of the prepared teeth.
[0006] In the prior art process, described in patent application US 2011/0159451, the dental preparation guide is generated by superimposing a virtual model of the teeth, prior to preparation with a virtual model, which expresses a target shape of the restored tooth. This approach also has some disadvantages, as described below.
[0007] The present invention solves the problems of the prior art processes.
[0008] A process to generate a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, the said process comprising: a: obtaining a 3D digital representation of a set of pre teeth -prepared; b: removing virtually at least one tooth from the 3D digital representation of the set of pre-prepared teeth, so that a 3D digital representation of a set of remaining teeth is formed; c: providing a desired virtual dental restoration by expressing a target form of dental restoration; d: create a virtual validation surface for the dental preparation guide, based on the desired virtual dental restoration, where the validation surface is such that the preparation of at least one tooth can be validated by the dental preparation guide; and e: create a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining teeth set.
[0009] A process for validating a preparation of at least one tooth in a set of prepared teeth is described, to determine whether the prepared tooth is capable of accepting a dental restoration, said process comprising: - obtaining a dental preparation guide virtual, configured to validate the preparation of at least one tooth; - obtain a 3D digital representation of the set of prepared teeth; - view the virtual dental preparation guide together with the 3D digital representation of the set of prepared teeth; and - validate the visualization of the virtual dental preparation guide, together with the 3D digital representation of the set of prepared teeth, if at least one prepared tooth is formed so that it can accept the dental restoration.
[00010] In some embodiments, the virtual dental preparation guide obtained is created by using an embodiment of the process to generate a dental preparation guide.
[00011] The described processes in which a validation surface of a dental preparation guide, to validate the preparation of a tooth, is created, at least in part, by using 3D digital representations of the patient's set of teeth, solve the problem. inaccuracy problem when defining the validation surface only of a physical model of teeth.
[00012] The dental preparation guide can be a virtual guide or a physical guide, in which the validation surface, in both cases, is such that the tooth preparation can be validated.
[00013] In the virtual case, the dental preparation guide is a virtual unit, which can be arranged in relation to a 3D digital representation of the patient's set of teeth. In the physical case, the physical dental preparation guide is manufactured from the created dental preparation guide and can be placed in the patient's mouth and physical contact or distance between surfaces can be used for validation.
[00014] The physical dental preparation guide can be manufactured based on the virtual dental preparation guide, so that the physical dental preparation guide comprises a validation surface corresponding to the virtual validation surface. In some cases, the physical dental preparation guide is such that, when it is placed in relation to the set of teeth in the patient's mouth, the validation surface defines a limit, within which the prepared tooth must be confined.
[00015] By generating the dental preparation guide for virtual surfaces, created from 3D digital representations of the patient's set of teeth, or by using the virtual surfaces themselves, as part of a virtual dental preparation guide, the present invention solves the problem of imprecision, which can be experienced when working with physical models of the set of teeth.
[00016] For a virtual dental preparation guide, the validation of the tooth preparation can be based on a visualization of the dental preparation guide, together with a 3D digital representation of the patient's set of teeth, for example, when at least a part of the tooth preparation has been conducted and the dentist wants to validate the preparation, to see if there is a need for further preparation.
[00017] For some embodiments of a physical dental preparation guide, according to the present invention, the validation of the tooth preparation is based on a record of physical contact between the dental preparation guide and the prepared tooth or teeth. After some preparation of the tooth, the dentist may want to validate the preparation of a tooth, to see if there is a need for further preparation. Then place the dental preparation guide on the patient's teeth and assess whether the preparation is complete or if additional material removal from the teeth is necessary. In some cases, the dental preparation guide is designed to ensure that it does not collide with the prepared tooth when the preparation is complete.
[00018] In some embodiments, the 3D digital representation of the set of remaining teeth comprises a section of the patient's gums. The surface of the virtual preparation guide can then include at least a part of the gingiva, and a manufactured dental preparation guide, which will be able to couple that section of the gum, when the dental preparation guide is used in the patient's mouth. The gingiva therefore supports the dental preparation guide, which can be correctly placed relative to the prepared tooth, even when the entire surface of the tooth is modified.
[00019] In some embodiments, the 3D digital representation of the set of remaining teeth comprises part of at least one of the neighboring teeth. This set can at least the neighboring teeth or teeth, and / or the longest teeth of the prepared tooth. The surface of the virtual preparation guide can then include at least a part of the surface of neighboring teeth, and a manufactured dental preparation guide will be able to couple these teeth when the dental preparation guide is used in the patient's mouth. Neighboring teeth therefore provide support for the dental preparation guide, which can be correctly arranged relative to the prepared tooth, even when the entire tooth surface is modified. The part of the dental preparation guide, which contacts the neighboring teeth, can be formed as wings, surrounding the part of the dental preparation guide, which is facing the prepared tooth.
[00020] Prior art processes, such as the process described in US patent application 2011/0159451, in which the dental preparation guide is designed only from the surface of the tooth, which is to be prepared, are unsuitable in the cases in which which the entire tooth surface will be modified by preparing the tooth. In such cases, for example, when the dental restoration is an integral crown, the prior art dental preparation guide does not have any surface that can support the dental preparation guide, to ensure that it is properly aligned with the prepared tooth. The embodiments of the present invention, in which the 3D digital representation of the set of remaining teeth and / or the gum solves the problem, since the dental preparation guide then has a surface, formed to couple a part of the patient's set of teeth , which is not modified during preparation. The dental preparation guide is also directed towards its correct disposition relative to the prepared tooth, even when the entire surface of the tooth is modified during the preparation.
[00021] Preferably, the virtual dental preparation guide is formed so that dental restoration can be done and can be accepted by the prepared tooth, when it is prepared according to the virtual dental preparation guide.
[00022] In some embodiments, the process for validating a preparation, using the dental preparation guide, comprises visualizing the surface of the virtual preparation guide or the virtual validation surface, together with the digital 3D representation of the set of remaining teeth. This can be, for example, the case when the virtual dental preparation guide is formed only by the surface of the virtual preparation guide or by the virtual validation surface. When using a virtual dental preparation guide to validate the preparation, there is no need, for example, to coat the surface of the virtual preparation guide to provide a solid model, which can be manufactured using direct digital manufacturing. It can therefore be advantageous for the virtual dental preparation guide to have only one surface, such as the virtual preparation guide surface or the virtual validation surface.
[00023] A process for manufacturing a dental preparation guide, configured to validate the preparation of at least one tooth, in a set of teeth for a dental restoration, is described, said process comprising: generating a virtual dental preparation guide using the process according to any one of the claims; and manufacturing the dental preparation guide from said virtual dental preparation guide using direct digital manufacturing.
[00024] When arranged in the patient's mouth in relation to the patient's teeth, the manufactured dental validation tool can validate the preparation of the tooth, so that the dentist can decide whether the preparation is complete or additional preparation work is needed.
[00025] A dental preparation guide, configured to validate the preparation of at least one tooth, in a set of teeth for a dental restoration, is described, said dental preparation guide comprising a surface facing the tooth, formed in accordance with with the virtual validation surface, generated by using the process according to one of the embodiments.
[00026] In some embodiments, the dental preparation guide is configured to validate the tooth preparation against a desired tooth preparation, in which the desired tooth preparation can be defined before any tooth preparation. This may be the case when the dentist or dental technician designed the dental restoration prior to tooth preparation, and created a desired tooth preparation based on the projected dental restoration. This approach has the advantage that the dentist, when part of the preparation of the tooth, can immediately obtain how the tooth should preferably be prepared. In difficult cases, such as when preparing several rotating teeth for a bridge restoration, this can be highly advantageous. The desired tooth preparation can also be defined during the procedure, such as after an initial preparation step. This approach has an advantage that, when the tooth that has to be prepared is sick, and the detailed knowledge of the strength of the internal parts of the tooth is unknown.
[00027] In some embodiments, the generated dental preparation guide is such that it can be arranged relative to the patient's set of teeth, with the validation surface facing the tooth. The tooth can be that of the set of pre-prepared teeth or that of the set of prepared teeth.
[00028] In some embodiments, the generated dental preparation guide is such that it can be arranged in relation to a 3D digital representation of the set of pre-prepared or prepared teeth, with the validation surface facing the tooth. By viewing a virtual dental preparation guide, arranged in relation to the 3D digital representation, direct information is often provided to the dentist regarding those parts of the tooth that need to be further prepared.
[00029] In the context of the present invention, the phrase "set of pre-prepared teeth" is used in relation to a set of teeth prior to preparation for which the dental preparation is designed for validation. In some cases, a previous preparation has been made on the set of pre-prepared teeth, such as a preparation of other teeth, or a first preparation used to assess the health of the tooth, to assess whether the entire tooth should be removed and replaced with one dental implant.
[00030] In some embodiments, the physical dental preparation guide is manufactured by direct digital manufacture, such as by printing or 3D lamination. With the continuous reduction in the acquisition costs of 3D printing and lamination systems for dental applications, this equipment is viable for the dentist, and once the virtual dental preparation guide is created, he can produce a physical guide in his consultation.
[00031] In the virtual case, the virtual dental preparation guide can be aligned with a 3D digital representation of the set of pre-prepared or prepared teeth, and virtual intersections of the surface or distance between the surfaces can be used for validation.
[00032] In the context of the present invention, the phrase "the dental preparation guide is configured to provide that ..." is sometimes used as a succinct form of "the dental preparation guide is configured to provide that a tooth preparation , according to the dental preparation guide, will ensure that ... ".
[00033] In the context of the present invention, a prepared tooth can also be referred to as a tooth preparation.
[00034] In the context of the present invention, a dental restoration is a classic fixed restoration, such as encrustation / scaling, polishing, crowns, bridges, structures retained by implants, etc., but, by analogy, also removable restorations, such as like dentures.
[00035] In the context of the present invention, a patient is the person for whom a restoration is designed. There may be medical indications for the dental treatment of this patient, but cosmetic considerations can also be a relevant motivation for having a dental restoration designed.
[00036] In the context of the present invention, the surface, provided by a Boolean addition of a first and a second surface, can correspond to the surface of a solid structure, formed by a logical disjunction of the solid structures with the surfaces according to the first and second surfaces.
[00037] It is an advantage of the present invention that it provides an efficient control in relation to the shape and position of the validation surface of the dental preparation guide, in comparison with the processes of the prior art.
[00038] Furthermore, the process of the present invention can create dental preparation guides, which are able to provide information on how appropriate a tooth preparation validation is compared to prior art dental preparation guides.
[00039] In some embodiments, the process according to the present invention is a process that is carried out in parallel with a treatment of a patient. The process of generating and / or manufacturing the dental preparation guide can be conducted in parallel with the dental work, performed by the dentist on the patient's set of teeth, just as in parallel with the preparation of the tooth or teeth. The preparation of the tooth is therefore not considered as part of the process.
[00040] According to one aspect of the invention, a process for generating a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, said process comprising: a: obtaining a 3D representation digital display of a set of pre-prepared teeth; b: virtually removing said at least one tooth from the 3D digital representation of a set of pre-prepared teeth, so that a 3D digital representation of a remaining set of teeth is formed; c: providing a desired virtual dental restoration by pressing a desired form of the dental restoration; d: create a virtual validation surface for the dental preparation guide based on the desired virtual dental restoration, where the validation surface is such that the tooth preparation can be validated by the dental preparation guide; and e: create a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining set of teeth.
[00041] In accordance with one aspect of the invention, a process for validating the preparation of at least one tooth for a dental restoration is described, said process comprising: - generating a virtual dental preparation guide, configured to validate the preparation of the at least one tooth; - obtain a 3D digital representation of the set of pre-prepared teeth; and - view the virtual dental preparation guide together with the 3D digital representation of the set of pre-prepared teeth.
[00042] In some embodiments, the combination of the virtual validation surface and at least part of the 3D digital representation of the remaining teeth set comprises connecting the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining teeth set , and thereby create the surface of the virtual preparation guide.
[00043] An advantage of this approach is that the virtual preparation guide surface created has both the validation surface and the surface that can contact and rest on areas of the set of teeth, which are not modified by the preparation.
[00044] In some embodiments, the target shape and / or the desired virtual dental restoration is (are) based on a projected virtual diagnostic wax mold, on a generic dental restoration selected from a library, or on the tooth shape in the 3D representation of the set of pre-prepared teeth. The target shape can be formed substantially in accordance with the original shape of the set of teeth, or it can be defined by modifying the 3D digital representation of the set of pre-prepared teeth.
[00045] An advantage of having a target shape, which is based on the shape of the tooth in the 3D digital representation of the set of pre-prepared teeth is that the patient is used to feel the teeth, which are, in this case, maintained .
[00046] An advantage of having a target shape, which is based on a projected virtual diagnostic wax mold, is that the appearance of the patient's set of teeth can be modified when the dental restoration is inserted into the prepared tooth.
[00047] In some embodiments, the target shape and / or the desired virtual dental restoration is (are) based (s) on one or more aesthetic parameters. The aesthetic parameter can be selected from the shape of the individual teeth, the color of the tooth or the relative arrangement of the teeth.
[00048] An advantage of this is that the target form of the dental restoration can be designed according to the patient's desire involving the aesthetic appearance of his set of teeth.
[00049] In some embodiments, the diagnostic wax mold is formed based on the 3D digital representation of the set of pre-prepared teeth, is selected from the library or is obtained by scanning a physical model of a diagnostic wax mold for the teeth .
[00050] In some embodiments, the diagnostic wax mold is generated by combining teeth from a model of teeth with the 3D digital representation of the set of pre-prepared teeth.
[00051] An advantage of a diagnostic wax mold, both of the teeth of a model of teeth, and of the 3D digital representation of the set of pre-prepared teeth, is that a real visualization of the expected result of the restoration work can be provided.
[00052] In some embodiments, the virtual diagnostic wax mold is generated by modifying at least a part of the 3D digital representation of the set of pre-prepared teeth, in which the modified parts refer to the tooth or teeth of the dental restoration.
[00053] In some embodiments, the design of the diagnostic wax mold is such that the diagnostic wax mold is automatically aligned with the 3D digital representation of the set of pre-prepared teeth, and / or the set of remaining teeth.
[00054] In some embodiments, the diagnostic wax mold is designed in relation to the 3D digital representation of the set of teeth, such as the 3D digital representation of the set of pre-prepared or prepared teeth, so that it is automatically aligned with the representation 3D digital of the set of remaining teeth. A defined desired dental restoration of the diagnostic wax mold will therefore consequently also be automatically aligned with the 3D digital representation of the remaining teeth set, and the virtual validation surface can be directly combined with the 3D digital representation of the remaining teeth set .
[00055] In some embodiments, at least part of the diagnostic wax mold is created using a tooth generating algorithm. This algorithm can be implemented on a computer.
[00056] In some embodiments, the virtual validation surface is created based on the diagnostic wax mold. This may be a desired dental restoration based on the diagnostic wax mold.
[00057] In some embodiments, the process comprises the definition of a 3D sectioning flute, configured to section virtually the 3D digital representation of the pre-prepared teeth into a part corresponding to the tooth and a part corresponding to the 3D digital representation of the set of teeth remaining. An advantage of this is that the tooth part can be removed virtually, and the digital 3D representation of the remaining teeth set can be used to generate the surface of the virtual preparation guide, without having the tooth part of the digital 3D representation of the set of pre-prepared teeth interfering with the design process.
[00058] In some embodiments, the virtual removal of the tooth comprises the definition of said 3D sectioning flute, and virtual division of the 3D digital representation of the pre-prepared teeth into a part corresponding to the tooth and a part corresponding to the 3D digital representation of the set of pre-prepared teeth in the 3D sectioning cannula.
[00059] The use of a 3D sectioning flute provides the advantage that an operator can define the flute itself, and thereby determine when the tooth part and the remaining set of teeth are separated.
[00060] The 3D sectioning flute can be defined automatically using a computer-implemented sectioning flute generation algorithm. The operator can inspect the location of the 3D sectioning flute relative to the 3D digital representation of the set of pre-prepared teeth, before approving the removal of the tooth in that flute.
[00061] In some embodiments, the process comprises manually defining the 3D sectioning flute, or manually adjusting an automatically generated 3D sectioning flute.
[00062] In some embodiments, the manual definition of the 3D sectioning flute or the manual adjustment of an automatically generated 3D section flute is based on the sectioning flute control points used to control the shape of the 3D sectioning flute. These control points have the advantage that the operator can adjust the 3D sectioning flute using a pointing tool, such as a computer mouse.
[00063] When sectioning the 3D digital representation, the 3D sectioning flute can be set to follow the gingival edge on the tooth.
[00064] An advantage of this is that in the 3D digital representation of the set of remaining teeth, the tooth surface is removed completely, and the virtual validation surface can be formed so as not to have any parts corresponding to the tooth surface. The surface of the created virtual preparation guide can then be shaped to correspond to a removal of material from the teeth over the entire surface of the tooth, as is often preferred when preparing the tooth for a crown restoration.
[00065] At least a part of the 3D sectioning flute for a tooth can be configured to be formed according to a predicted shape of the preparation line, which is provided when the tooth is prepared. That is, in both cases in which the 3D sectioning flute is generated automatically, and when it is defined manually, it can be arranged to follow a path along which the operator plans to define a tooth preparation line.
[00066] An advantage of this is that the dental preparation guide can be designed to assist the dentist in correctly placing the preparation line.
[00067] In some embodiments, the virtual sectioning of the part of the 3D digital representation, corresponding to the tooth, is such that this part can be separated virtually from the 3D digital representation of the pre-prepared teeth and can be moved away or eliminated from it.
[00068] It may be advantageous that, when viewing the 3D digital representation of the set of remaining teeth and the virtual surfaces of the dental preparation guide, the tooth is no longer visible.
[00069] In some embodiments, the tooth is removed virtually from the 3D digital representation of the set of pre-prepared teeth by virtual separation of the part corresponding to the tooth from the part corresponding to the set of remaining teeth. The tooth part can still be arranged in the same position as the 3D digital representation of the tooth set, as before removal, but the removed part is not included in the remaining tooth set.
[00070] It may also be possible to omit the virtual tooth removal step, as long as its surface is indicated to be distinct from the remaining part of the set of teeth. This can be done, for example, by adding information to the surface of the removed tooth in virtually another way. In the visualization of the virtual preparation guide surface of the dental preparation guide, the tooth can then be presented as a highly or at least slightly transparent surface. A flute of the remaining 3D teeth can then be formed in relation to the 3D digital representation of the set of pre-prepared teeth, which has the tooth viewed differently.
[00071] The 3D sectioning flute can be used to define a tooth, which can subsequently be virtually separated or separated virtually away from the 3D digital representation of the set of pre-prepared teeth.
[00072] When several teeth are removed virtually, the 3D sectioning can virtually section the digital 3D representation of the prepared teeth into a part corresponding to those teeth and a part corresponding to the set of remaining teeth.
[00073] In some embodiments, the 3D sectioning flute substantially follows a boundary between the desired dental restoration and the 3D digital representation of the set of pre-prepared teeth.
[00074] The virtual removal of the tooth can introduce a virtual hole in the 3D digital representation of the set of remaining teeth. The virtual hole can comprise a gingival hole and interproximal holes in neighboring teeth, if these are still present in the 3D digital representation of the set of remaining teeth. The virtual hole can be connected by the 3D sectioning flute.
[00075] In some embodiments, the process comprises creating a virtual replacement surface, configured to close, at least partially, the virtual hole, such as substantially closing the virtual hole. The virtual replacement surface can be a generic surface, selected from a library, or a surface generated using curvature-based hole closing algorithms. In some embodiments, the virtual replacement surface comprises a virtual gingival surface, such as a virtual gum. In some embodiments, the virtual replacement surface comprises a virtual tooth preparation.
[00076] An advantage of creating this virtual replacement surface is that this surface can be used when defining an interproximal section of a flute of the remaining 3D teeth.
[00077] In some embodiments, at least a section of the 3D remaining toothed crown is configured to follow a virtual hole limit, introduced in the 3D digital representation of the remaining teeth set, by virtual tooth removal.
[00078] The definition of a flute of the remaining 3D teeth has the advantage that this flute can mark the place where the 3D digital representation of the set of remaining teeth connects to the virtual surfaces, used when generating the surface of the preparation guide virtual.
[00079] In some embodiments, the 3D remaining teeth flute is defined from the 3D sectioning flute, so that at least a section of the 3D remaining teeth flute is formed substantially in accordance with the 3D sectioning flute.
[00080] This has the advantage that the dentist or dental technician often prefers that at least some sections of the flute of the remaining 3D teeth have the same shape as the flute used to section the digital 3D representation of the pre-prepared set of teeth. .
[00081] In some embodiments, the flute of the remaining 3D teeth comprises a lingual part and / or a buccal / labial part and / or an interproximal part. The lingual part and the buccal / labial part of the flute of the remaining 3D teeth can be configured to follow the limit of the virtual hole in the lingual and buccal parts of the set of teeth, respectively.
[00082] In some embodiments, the lingual part and / or the buccal / labial part of the flute of the remaining 3D teeth is (are) substantially identical to the 3D sectioning flute of the corresponding parts of the digital 3D representation of the pre-set of teeth -prepared.
[00083] In some embodiments, the flute of the remaining 3D teeth comprises an interproximal part. The interproximal part is preferably defined by modifying the 3D sectioning flute. In some cases, a section of the 3D sectioning flute follows the interproximal limit, between the tooth, which will be virtually removed, and its neighboring tooth, in such a way that the 3D sectioning flute is moved away from the gum. When defining the flute of the remaining 3D teeth by modifying the 3D sectioning flute, this section of the 3D sectioning flute can be formed to follow the gingiva in the interproximal part of the tooth.
[00084] This has the advantage that the flute of the remaining 3D teeth is formed in a way that resembles the anatomical situation, so that when the surface of the virtual preparation guide is defined by connecting the digital 3D representation of the remaining teeth set , in the flute of the remaining 3D teeth, the created surface has a more homogeneous shape, compared to the case in which the flute of the remaining 3D teeth is identical to the agricultural storage system, which is, in the interproximal parts, distant from the gum.
[00085] In some embodiments, the interproximal part of the cannula of the remaining 3D teeth is arranged so that it divides at least a part of said virtual hole into an interproximal hole and a gingival hole.
[00086] In some embodiments, the interproximal part of the 3D remaining tooth cannula is arranged so that it follows the virtual replacement surface and divides at least a part of said virtual replacement surface into a virtual interproximal surface and a gingival surface virtual.
[00087] In some embodiments, the flute of the remaining 3D teeth is defined in relation to the virtual replacement surface. The flute of the remaining 3D teeth can be arranged to divide the virtual replacement surface into the virtual gingival surface and one or two virtual interproximal surfaces, depending on whether the neighboring teeth are still present in the 3D digital representation of the set of remaining teeth.
[00088] In some embodiments, the process involves creating a virtual gingival surface, configured to close at least part of the gingival hole in the 3D digital representation of the set of remaining teeth.
[00089] This surface can be used when defining other surfaces or flutes used in the process, or to digitally design the dental restoration, such as designing a bridge restoration pontic.
[00090] In some embodiments, the process involves creating a virtual interproximal surface, configured to close at least part of the interproximal hole in the 3D digital representation of the set of remaining teeth.
[00091] The virtual gingival surface and / or the virtual interproximal surface can be created using a curvature-based hole closure algorithm.
[00092] In some embodiments, the process comprises producing the part of the virtual gingival surface and / or the virtual interproximal surface and / or the virtual replacement surface of the 3D digital representation of the remaining teeth set. The making can comprise connecting the virtual gingival surface and / or the virtual inter-proximal surface and / or the virtual replacement surface with the 3D digital representation of the remaining teeth set. The surfaces can be connected with the 3D digital representation of the set of remaining teeth by a tracing process.
[00093] For the virtual gingival surface, this may correspond to virtually replacing the tooth removed from virtually the remaining set of teeth. This surface can be used, for example, in the design of dental restoration, such as when designing a pontic for a bridge restoration.
[00094] In some embodiments, the virtual validation surface is formed according to the desired virtual dental restoration. Validation using the dental preparation guide can then comprise estimating the difference between a pre-prepared tooth shape and the desired dental restoration shape. This dental preparation guide can be useful in cases where the desired dental restorations differ significantly from the shape of the teeth, in the set of pre-prepared teeth, as this dental preparation guide can provide the dentist with an indication of how far the tooth is from shape according to the diagnostic wax mold, and therefore when and how much of the tooth material must be removed. The tooth must then be prepared from the validation surface, and, for example, the space available for the 3D digital representation must be estimated from the space between the validation surface and the surface of the set of prepared teeth.
[00095] In some embodiments, the process involves creating a minimal virtual preparation surface. The removed tooth can then virtually be replaced by the virtual minimum preparation surface in the 3D digital representation of the remaining tooth set. The virtual minimum preparation surface can show the maximum size of the prepared tooth, that is, a boundary within the prepared tooth, which has to be confined to ensure that sufficient space is provided for dental restoration.
[00096] In some embodiments, the minimum virtual tooth preparation surface is determined from the desired virtual 3D digital representation. The virtual minimum preparation surface is then formed so that a tooth, prepared according to that surface, is ready to accept a digital 3D representation formed according to the desired 3D digital representation.
[00097] In some embodiments, the minimum virtual tooth preparation surface is determined by displacement of at least part of the desired virtual dental restoration inward. The degree of displacement can be uniform or vary across the tooth surface, so that the displacement, for example, is greater than the occlusal end of the prepared tooth. The offset can be determined from parameter values entered by an operator or from predefined values for those parameters.
[00098] An advantage of determining the virtual minimum preparation surface for this displacement is that the displacement directly provides a measure of a minimum thickness of the dental restoration, so that the mechanical stability of the dental restoration, and, for example, its capacity with regarding color variation can be considered.
[00099] In some embodiments, the virtual validation surface is designed so that the tooth material must be removed from areas that are, in fact, within the minimal preparation surface. This can be done to ensure that the surface of the prepared tooth is rough, so that the dental restoration is more close to the prepared tooth.
[000100] In some embodiments, the virtual validation surface is modified to provide the virtual dental preparation guide to follow the tooth surface in regions where the virtual validation surface will otherwise be located outside the tooth. This can be done, for example, when a virtual minimum preparation surface of the tooth is formed by a displacement of the desired virtual dental restoration, and a part of the virtual minimum preparation surface extends out of the tooth. The parts of the displaced surface, which extend beyond the tooth, are then pushed virtually into the tooth surface, or cut virtually from the tooth surface. For a physical dental preparation guide, the pushed sections can rest on the relative surface of the prepared tooth, and thereby provide that the dental preparation guide is supported in its correct arrangement relative to the patient's set of teeth.
[000101] In some embodiments, the properties of the material, from which the dental restoration will be produced, are considered, as they were when determining the virtual minimum preparation surface. The minimum thickness and critical angles for dental restoration depend on the material. When considering the properties of the material, the dental restoration can be designed to have some desired mechanical and color-changing properties, and the tooth can be prepared to accept a restoration, which is designed to meet the requirements for those properties.
[000102] The minimum thickness of the restoration wall depends on the material of the restoration. A minimum thickness is, for example, necessary to provide a consistent design of the 3D digital representation, when the restoration is made in gold, while another minimum thickness is necessary, when it is made in ceramic.
[000103] The shape of the prepared tooth is preferably also adjusted to match the material of the restoration. A restoration made of gold may have a cuneiform finish towards the preparation line of the prepared tooth, while a ceramic restoration often requires a more abrupt finish.
[000104] In some embodiments, the generation of the dental preparation guide considers these aspects, so that the dental preparation guide is configured to guide the drill, to provide a prepared tooth, in which a restoration having a cuneiform or abrupt finish can be willing.
[000105] In some embodiments, the virtual minimum preparation surface and / or the virtual validation surface is or are such that a volume for cement is provided between the prepared tooth and the dental restoration, when the dental restoration is arranged on the teeth of the patient. This has the advantage that cement can be applied to the tooth / dental restoration, without scraping even more material.
[000106] In some embodiments, a virtual preparation line is defined in relation to the virtual validation surface.
[000107] In some embodiments, the virtual validation surface is based on the virtual minimum preparation surface. In such cases, the virtual preparation line can be defined in relation to the virtual minimum preparation surface.
[000108] In some embodiments, the virtual preparation line is defined on the virtual validation surface, and corresponds to a virtual equivalent of a preparation line, defined by preparation of the real tooth.
[000109] In some embodiments, the virtual preparation guide surface is created by virtual connection of the virtual minimum preparation surface and the 3D digital representation of the remaining teeth set, that is, the virtual minimum preparation surface and the 3D digital representation of the set of remaining teeth are combined by connecting these surfaces. In that case, at least a part of the virtual validation surface is substantially identical to the virtual minimum staging surface.
[000110] In some embodiments, the virtual minimum preparation surface is represented by a virtual minimum preparation. In a user interface according to the present invention, this virtual minimum preparation can be viewed together with the 3D digital representation of the remaining teeth set, so that the operator can assess how good the minimum preparation will be in relation to the process of preparation and in relation to the insertion of the manufactured restoration.
[000111] In some embodiments, the surface of the virtual preparation guide is formed according to the virtual minimum preparation. Some parts of the virtual preparation guide surface can be configured to strictly follow the minimum preparation, while in other parts, such as when a safety zone is desirable, the surface of the virtual preparation guide can deviate from the virtual minimum preparation.
[000112] In some embodiments, the surface of the virtual preparation guide is, at least in part, created by a Boolean addition of the virtual minimum preparation surface and the 3D digital representation of the remaining teeth set.
[000113] In this approach, the surface of the virtual preparation guide can be easily generated once the virtual minimum preparation surface and the 3D digital representation of the set of remaining teeth are arranged relatively to each other in a way that the operator considers appropriate. For an implementation of the process presented to the operator in a user interface, the user interface can be a window showing the minimum virtual preparation surface and the 3D digital representation of the set of remaining teeth, and a virtual button, which, when enabled, performs the Boolean addition. The operator may be able to move to adapt the virtual minimum preparation surface and / or move it relative to the 3D digital representation of the remaining teeth set, using, for example, a computer mouse to perform these actions on the minimum preparation surface virtual in said window.
[000114] In some embodiments, the surface of the virtual preparation guide is, at least in part, created by a Boolean addition of the virtual validation surface and the 3D digital representation of the set of remaining teeth. The comments presented above regarding the Boolean addition of the virtual minimum preparation surface and the 3D digital representation of the remaining teeth set also apply to the Boolean addition of the virtual validation surface and the 3D digital representation of the remaining teeth set.
[000115] In some embodiments, the process comprises generating a connection surface, configured to connect the virtual validation surface and the 3D digital representation of the remaining teeth set.
[000116] The connecting surface can close the holes in the surface of the virtual preparation guide, located between the virtual validation surface and the 3D digital representation of the remaining tooth set, so that a coherent virtual preparation guide surface is created .
[000117] In some embodiments, the connection surface is configured to connect to the 3D digital representation of the set of remaining teeth, in the flute of the remaining 3D teeth. This approach has the advantage that an operator can determine, by the shape of the flute of the remaining 3D teeth, how the surface of the created virtual preparation guide is formed in the 3D digital representation of the remaining teeth. Furthermore, the operator can determine where the surface of the virtual preparation guide is formed, according to the 3D digital representation of the remaining teeth, and where it is formed, according to the virtual validation surface.
[000118] In some embodiments, generating the connecting surface comprises a tracing process. The trace can be applied to connect two surfaces by a new surface. A tracing process may comprise placing a parametric surface at the boundary of one surface and at the boundary of a second surface. The tracing process can be used to define a connection surface, configured to connect the virtual validation surface with the 3D digital representation of the set of remaining teeth.
[000119] In some embodiments, the formation of the connection surface is controlled by computer or assisted by computer.
[000120] In some embodiments, the process comprises defining a 3D validation surface flute in relation to the virtual validation surface, where the connection surface is configured to connect to the virtual validation surface in the 3D validation surface flute .
[000121] The use of a fluted 3D validation surface, to determine where the connection surface is configured to connect to the virtual validation surface, has the advantage that the operator can decide, for example, to connect to the surface virtual validation above a virtual preparation line of the virtual validation surface, so that a security zone is defined.
[000122] In some embodiments, the flute of the 3D validation surface is automatically defined using a computer-implemented algorithm.
[000123] An advantage of this is that the algorithm implemented by computer can define the flute of the 3D validation surface faster than the operator.
[000124] In some embodiments, the flute of the 3D validation surface is manually defined or adjusted using virtual control points, visualized in combination with a visualization of the diagnostic wax mold.
[000125] An advantage of this is that the operator is left to define the 3D validation surface according to his personal preferences.
[000126] In some embodiments, the flute of the 3D validation surface is configured to follow substantially the virtual preparation line.
[000127] In some embodiments, the 3D validation surface flute is located above the virtual preparation line, that is, the 3D validation surface flute is closer to the occlusal plane of the tooth than the virtual preparation line is.
[000128] In some embodiments, a hole-closing algorithm implemented by computer, is applied in the closing of holes and / or in the generation of the connection surface.
[000129] An advantage of this is that the hole-closing algorithm implemented by computer can virtually close the hole and / or generate the connection surface faster than an operator.
[000130] One way to perform a tracing process is to first determine a correspondence between the vertices at the two limits, which will be connected by the generated surface. The correspondence can be determined by an exhaustive search for the correspondence that generates the smallest average distance between the corresponding vertices, under the limitation that the order of the vertices is maintained. The trace can be based on a cubic B flute surface, which requires the specification of several control points. For each vertex, the vector vc is calculated, which is perpendicular to the normal of the vertex and to the limit orientation vector at the vertex. The vertex normal is calculated as a weighted average of the area of the triangle normals of the triangles connected to the vertex. For each vertex in the corresponding vertex set, two control points are created as the ± vc vertex. An additional control point is then created as vc1 and vc2, added to the intermediate point between the corresponding vertices p1 and p2. In addition to the created control points, the two vertices also act as control points. When this process has been repeated for all corresponding sets of vertices, the surface is entirely defined by the control points. The new vertices are then sampled on the surface, that is, by sampling the vertices in the flute, which connect the corresponding vertices. In view of these vertices and the ordering of the corresponding vertex sets, the neighbor relationships between the sampled vertices are known. The knowledge of these relations facilitates the connection of neighboring vertices by triangles. When the trace has been applied, it does not guarantee that, for example, the virtual validation surface is not penetrated by the connection surface. Penetration can, however, be minimized by moving the control points behind the validation surface, as well as moving the additional control point between the corresponding vertices backwards, along vc1 and vc2, until it is behind the surface. of virtual validation.
[000131] In some embodiments, the surface of the virtual preparation guide is configured to define a safety zone in the virtual preparation line and / or in the 3D sectioning flute, in which said safety zone provides a distance between the 3D representation digital display of the set of remaining teeth and the surface of the virtual preparation guide.
[000132] The safety zone can therefore provide space, in which the dentist can select between different locations of the preparation line for the tooth and / or the line of the preparation margin relative to the gum. The safety zone can also ensure that the dental preparation guide does not make contact with sensitive parts of the gum when placed on the patient's teeth. A safety zone can be generated when the flute of the 3D validation surface is located above the virtual preparation line. In this case, the surface of the virtual preparation guide is displaced locally from the virtual preparation line, with which the space of the security zone is promoted.
[000133] In some embodiments, the dental preparation guide is manufactured by direct digital manufacture, such as by printing or 3D lamination.
[000134] In some embodiments, the dental preparation guide is manufactured by: - formation of a physical model of the set of teeth, in which the tooth is prepared according to the virtual validation surface; and - formation of the material of the dental preparation guide according to this physical model.
[000135] The material formation of the dental preparation guide may comprise vacuum formation of the material in the physical model. This approach has the advantage that although very few biocompatible materials can be used for direct digital manufacturing, there are many biocompatible materials, which can be vacuum formed into a solid model.
[000136] In some embodiments, the generated virtual dental preparation guide comprises a coated virtual preparation guide surface.
[000137] An advantage of the surface coating of the virtual preparation guide is that the surface itself may not necessarily be used for direct digital manufacturing, whereas a virtual model, defined by the surface coating, is suitable for that manufacture.
[000138] In some embodiments, the process comprises coating at least a selected part of the surface of the virtual preparation guide, so that the virtual dental preparation guide comprises an internal coating surface and an external coating surface on the selected part.
[000139] In some embodiments, the surface of the virtual preparation guide and / or the virtual validation surface is (are) parameterized (s) by several vertices, in which the vertices are connected by triangles.
[000140] In some embodiments, the outer cladding surface is formed according to the virtual validation surface.
[000141] In some embodiments, the outer coating surface is formed according to the surface of the virtual preparation guide created, and the coating defines the inner coating surface of the outer coating surface. In that case, the coating may comprise moving a copy of each vertex into the outer coating surface, removing the number of copied vertices being closer to the outer coating surface than a predetermined minimum coating thickness, and creating the coating surface. internal by triangulation of the remaining copied vertices.
[000142] When the outer covering surface is formed according to the surface of the virtual preparation guide created, the outer covering surface can be according to the target shape of the dental restoration.
[000143] In some embodiments, an intermediate physical model is manufactured from the surface of the coated virtual preparation guide using direct digital manufacturing. The dental preparation guide can then be manufactured from the material of the dental preparation guide, using said intermediate physical model. The internal surface and external surfaces of the intermediate physical model can be defined by the internal coating surface and the external coating surface, respectively.
[000144] The outer surface of the intermediate physical model can be formed according to the surface of the virtual preparation guide, and the manufacture of the dental preparation guide can be such that the internal surface of the manufactured dental preparation guide is formed according to the outer surface of the intermediate physical model. The inner surface of the manufactured dental preparation guide then corresponds to a negative of the surface of the virtual preparation guide, and the dental preparation guide fits into a tooth, prepared according to the surface of the virtual preparation guide. If the tooth is further prepared, a gap is present between the internal surface and the surface of the tooth, when the dental preparation guide is placed on the patient's set of teeth.
[000145] This approach has the advantage that although only very few biocompatible materials can be used for direct digital manufacturing, there are a lot of biocompatible materials that can be vacuum formed in this intermediate physical model.
[000146] In some embodiments, forming the material of the dental preparation guide using said intermediate physical model comprises vacuum forming the material of the dental preparation guide in the intermediate physical model.
[000147] In some embodiments, the dental preparation guide is such that the internal coated surface is formed according to the virtual validation surface.
[000148] In some embodiments, the inner coating surface is formed according to the surface of the virtual preparation guide, and the coating defines the outer coating surface of the inner coating surface. The inner lining surface can be on the surface that faces the set of teeth, when the dental preparation guide is placed on the teeth, while the outer lining surface faces the surrounding buccal, labial and lingual tissues and the antagonist.
[000149] When the dental preparation guide and / or the virtual preparation guide surface is part of an internal coating surface, the coating may provide an external coating surface. In that case, the coating may comprise moving out a copy of each vertex on the inner coating surface, removing the various copied vertices closer to the inner coating surface than a predetermined minimum coating thickness, and creating the outer coating surface by triangulation of the remaining copied vertices.
[000150] This approach has the advantage that the dental preparation guide can be manufactured directly, without the need for an intermediate physical model.
[000151] In some embodiments, the dental preparation guide is manufactured from said surface of the coated virtual preparation guide, using direct digital manufacturing. This may be the case when the inner coating surface is formed according to the surface of the virtual preparation guide.
[000152] The coating can expand the surface of the virtual preparation guide, so that a coating with a finite thickness remains. For many devices, it is beneficial or crucial that a minimum coating thickness is guaranteed.
[000153] In a coating algorithm, configured to provide a coating based on an external coating surface, the first step is to create a copy of each vertex on the external coating surface. A new vertex in the inner cladding is created along a staggered normal of the corresponding vertex in the outer cladding surface. The vertex normal is calculated as the average of the normals of the connected triangles weighted by their areas. If the minimum coating thickness has to be guaranteed, it is not enough to move the vertex with the specific coating thickness. However, the displacement, which guarantees the coating thickness locally, can be verified as the minimum scale factor, which projects the scaled version of the vertex normal in the full length of the triangle normals scaled by the predefined thickness. Only the normals of the triangles connected to the vertex are relevant. Unfortunately, the proposed offset only guarantees a local coating thickness. In areas with convex surfaces and high curvature, the displaced vertices tend to violate the minimum coating thickness. These violating vertices are removed in a second step, to ensure adequate coating thickness. Finally, the new inner lining can then be created by triangulating the created vertices. Triangulation can be done using a standard 3D triangulation process, such as one proposed by Hoppe et al. in "Surface Reconstruction from unorganized points", Computer Graphics, 26 (2), 1992, p. 71 - 78.
[000154] In some embodiments, the dental preparation guide is generated so that it can be arranged relative to the patient's set of teeth with the validation surface facing the tooth. The tooth can be that of the set of pre-prepared teeth or prepared teeth.
[000155] A base can be provided on the surface of the coated virtual preparation guide, prior to the manufacture of the physical dental preparation guide. The base can be located on the occlusal part of the outer cladding surface.
[000156] A base can be provided on the surface of the coated virtual preparation guide, prior to the manufacture of the intermediate physical model. The base can be located on the cervical part of the coated surface.
[000157] The validation surface is configured to validate the preparation of one or more teeth in the set of teeth. In some embodiments, such as when the validation surface is in accordance with minimal tooth preparation, insufficient tooth preparation will prevent the dental preparation guide from reaching a target position relative to the set of teeth. If the preparation is sufficient and there are no other teeth that need (more) preparation, the dental preparation guide can be moved to the target position. If the dental preparation guide is manufactured from a relative soft material, it may still be possible for the dental preparation guide to reach the target position, even with insufficient tooth preparation, but then resistance is experienced.
[000158] In some embodiments, the process comprises determining an insertion direction for dental restoration, and in which the insertion direction is considered when creating the virtual validation surface, so that, for example, the minimum preparation surface can be based on the insertion direction.
[000159] In some embodiments, considering the insertion direction comprises ensuring that the virtual validation surface is configured to provide that undercuts on the prepared tooth are reduced or avoided, if the tooth is prepared according to the virtual validation surface, such as according to the validation surface of a physical dental preparation guide, manufactured based on the virtual dental preparation guide. In some embodiments, drawdowns are reduced or avoided by cutting the virtual validation surface.
[000160] In the context of the present invention, the phrase "dentings on the prepared tooth" can refer to observed dentings relative to the path of the dental restorations along the insertion direction, as illustrated in figure 8, in which the dental restoration cannot be arranged on the prepared tooth, due to this lowering.
[000161] In some embodiments, the process comprises generating a virtual surface free of drawdown of the minimum virtual preparation surface, and the virtual validation surface is created based on the virtual surface free of drawdown. The free recess surface can be generated using a virtual locking tool, configured to block the recess regions in the 3D digital representation of the set of pre-prepared or prepared teeth.
[000162] In some embodiments, a downward narrowing is provided on the virtual minimum preparation surface and / or on the virtual lowering-free surface, where the narrowing is from the virtual preparation line to the occlusal surface of the tooth with a narrowing angle. The narrowing angle can be in the range of about 0.5 degrees to about 15 degrees, such as in the range of 1 degree to about 10 degrees, as well as in the range of about 2 degrees to about 5 degrees.
[000163] In some embodiments, the dental restoration comprises a bridge restoration, a single crown, a temporary restoration or a removable partial denture.
[000164] In some embodiments, the dental restoration comprises a bridge restoration, and the dental preparation guide is configured to validate the preparation of two or more teeth, to accept the crown parts of the bridge restoration.
[000165] In some embodiments, the dental restoration comprises a mobile partial denture, and the dental preparation guide is configured to validate the preparation of two or more teeth, to fix the partial denture in the patient's mouth.
[000166] In some embodiments, the dental preparation guide is configured to validate the preparation of two or more teeth. In that case, one or more teeth can be removed virtually from the 3D digital representation of the set of pre-prepared teeth, so that the set of remaining teeth lacks one or more teeth, compared to the set of pre-prepared teeth. The 3D sectioning cannula can be defined for each tooth or for two or more teeth. Some teeth in the digital 3D representation of the pre-prepared set of teeth can then be virtually replaced by a minimal virtual preparation surface or minimal gingival in the digital 3D representation of the remaining set of teeth. A virtual diagnostic wax mold for a bridge restoration can, for example, be designed based on a selected model from a library.
[000167] In some embodiments, the dental preparation guide is configured to be used in relation to a first region and a second region of the set of teeth, wherein said first region comprises teeth related to dental restoration, and said second The region comprises at least one additional tooth, where the second region is used to correctly align the dental preparation guide for the set of teeth.
[000168] If the dental restoration is a bridge restoration for the teeth of the anterior jaw, with a pontic for tooth 8 and tooth 9, and crowns of the bridge attached to tooth 7 and tooth 10, the first region comprises teeth 7 - 10, while the second region comprises tooth 6 and tooth 11, or the teeth furthest from teeth 7 - 10. The teeth are numbered according to the universal tooth indication system. In that case, the dental preparation guide is therefore configured to couple not only the prepared teeth, but also at least one other tooth, which then ensures that the dental preparation guide is correctly aligned relative to the prepared teeth. A manufactured dental preparation guide can then be configured to be arranged for both teeth in the first and second regions. The alignment of the dental preparation guide is provided on the teeth of the second region, while the dental preparation guide validates the preparation of tooth 7 and tooth 10. Teeth 8 and 9 may have already been extracted before the validation of teeth preparation. 7 and 10. Alternatively or in addition to using neighboring teeth, to support the dental preparation guide, the gingiva can be used for this purpose, and the corresponding part of the 3D digital representation of the set of remaining teeth is included when generating the surface of the virtual preparation guide.
[000169] In some embodiments, at least one opening is defined in the surface of the virtual preparation guide coated with the dental preparation guide, so that when the manufactured dental preparation guide is arranged in relation to the patient's set of teeth, the opening provides access to an area of the tooth. The tooth can be prepared or unprepared. A pointed tool can then enter through the opening of the manufactured dental preparation guide and measure the distance from the dental preparation guide to the tooth surface. This can be used, for example, when the validation surface of the dental preparation guide is formed according to a diagnostic wax model, as it allows the dentist to measure whether the space provided for dental restoration, by preparing of the tooth, it is large enough so that a robust dental restoration can be made.
[000170] In some embodiments, the validation surface is configured to validate the preparation of at least one tooth or teeth surface, such as a buccal, lingual, occlusal or interproximal surface of the tooth or teeth. In some embodiments, the validation surface is configured to validate the preparation of the entire tooth surface.
[000171] In one embodiment, the process comprises creating an intermediate version of the minimum preparation surface. The intermediate version can be formed according to an eggshell configuration, in which the eggshell configuration can be defined by displacing at least part of the desired virtual dental restoration surface, thereby forming a surface internal lining.
[000172] The preparation of the tooth, physical or virtual, can be configured so that the restoration provides the desired aesthetic appearance. That is, the preparation is adapted to provide that the dental restoration can have the desired shape, placement and color.
[000173] In some embodiments, the desired virtual dental restoration and the 3D digital representation of the set of remaining teeth are aligned in the 3D sectioning flute. If there is a gap between the two, that gap can be closed using the hole-closing algorithms, such as a curvature-based hole-closing algorithm, or through a connection surface, configured to connect the virtual dental restoration. desired 3D digital representation of the set of remaining teeth.
[000174] In some embodiments, the process comprises combining the minimum virtual preparation and the gingival part of the virtual validation surface. If there is one between the two, this gap can be closed using hole closing algorithms, such as a curvature-based hole closing algorithm.
[000175] In some embodiments, the process comprises aligning the virtual validation surface and / or the minimum virtual preparation with the 3D digital representation of the remaining teeth set. The virtual validation surface and the 3D digital representation of the remaining teeth set can be automatically aligned when the virtual validation surface is generated from a diagnostic wax mold, which is aligned with the digital 3D representation of the remaining teeth set.
[000176] In some embodiments, the process comprises that information regarding the size and / or shape of the drill used to prepare the tooth is provided, and the generation of the dental preparation guide considers said information.
[000177] In some embodiments, the dental preparation guide is generated without considering the information, and in which an estimated shape of the prepared tooth is visualized, in which the estimated shape is derived considering the information.
[000178] In some embodiments, the process involves modifying the dental restoration, so that it can be accepted by the prepared tooth. This may be necessary, for example, when the dentist is unable to prepare the tooth according to the dental preparation guide. In some cases, a small variation in the dental restoration can solve the problem and ensure that the dental restoration can be accepted by the prepared tooth.
[000179] In some embodiments, the process involves visualizing the desired virtual dental restoration, in relation to the 3D digital representation of the set of remaining teeth. This has the advantage that the dentist and the patient can assess the aesthetic appearance of the teeth, when the dental restoration is inserted into the patient's mouth.
[000180] In some embodiments, the process involves generating a virtual structure with a surface, which is traced by translating the virtual preparation line, along the insertion direction.
[000181] In some embodiments, the virtual validation surface is created based on the virtual structure, so that the virtual validation surface considers the insertion direction. This has the advantage that the manufactured dental restoration can be inserted into the prepared tooth according to the dental preparation guide.
[000182] In some embodiments, a descending narrowing is provided in the virtual structure, from the virtual preparation line to the occlusal surface of the tooth with a narrowing angle, so that the virtual structure can be formed as a cone trunk.
[000183] If the insertion direction is ignored, a lowering surface can be generated in the appearance of the tooth, even when the tooth is prepared according to the validation surface.
[000184] In some embodiments, the process comprises generating a virtual surface free from the lowering of the minimum virtual preparation surface and the virtual structure. In some embodiments, the validation surface is created on the basis of the virtual surface without drawdown. The undercut surface can be such that small undercuts below a specific size are accepted.
[000185] This has the advantage that a preparation, formed according to the validation surface, will not have any lowering regions (relative to the insertion direction), and the dental restoration can be arranged on the prepared tooth.
[000186] In some embodiments, the virtual surface without drawdown corresponds to the surface of the virtual solid structure, formed by a Boolean addition of the virtual structure and a solid structure with a surface according to the virtual minimum preparation surface.
[000187] In some embodiments, 3D digital representation is provided by intraoral 3D scanning of the set of teeth, or 3D by scanning of a physical model or impression of the set of teeth.
[000188] In some embodiments, the 3D scan is done by means of a laser light scan, white light scan, probe scan, X-ray scan and / or CT scan.
[000189] In some embodiments, the 3D digital representation comprises at least part of the gum.
[000190] The 3D digital representation can be point clouds, surface (faceted / reticulated) or volumetric. Faceted / lattice models are sometimes preferred over point clouds, but faceted / lattice models can be generated from point clouds, for example, by triangulation. Volumetric models can be obtained with a scanning device applying penetrating radiation, such as CT scanning devices.
[000191] Some initial preparation may have been done on the teeth of the pre-prepared set of teeth. The process can be, for example, a step in an iterative procedure to prepare the patient's set of teeth, so that the shape of the tooth, in the set of pre-prepared teeth, can be an intermediate shape, as seen in a scan tooth, which has been exposed to an initial preparation at an earlier stage of the procedure.
[000192] In some embodiments, the set of pre-prepared teeth corresponds to the set of teeth of the patient before any preparation.
[000193] The set of teeth can comprise all or part of the patient's teeth.
[000194] In some embodiments, the 3D digital representation of the set of prepared teeth is obtained by scanning a prepared region comprising the prepared tooth, and joining the 3D digital representation, obtained from scanning the prepared region, with a digital 3D representation previously obtained of the set of pre-prepared teeth. This has the advantage that a full scan is not necessary when scanning the set of prepared teeth, and this time can be saved. The part of the 3D digital representation of the set of pre-prepared teeth, corresponding to the prepared region, can be eliminated or it can be distinct from the set of prepared teeth, so that, in fact, this part is replaced by the 3D digital representation of the prepared region. .
[000195] In some embodiments, one or more parameters related to dental restoration are considered when generating the dental preparation guide. One or more parameters can be selected from the group of minimum thickness of the restoration walls, the restoration material (s), the access for a drill to prepare the tooth, or the direction of insertion of the dental restoration.
[000196] In some embodiments, the dental preparation guide, used to validate the preparation of a tooth, is generated by using the process to generate a dental preparation guide according to the present invention.
[000197] The validation of the preparation of the tooth may comprise confirming that the shape of the prepared tooth is such that said dental restoration can be done and can be inserted into the prepared tooth. Validation can be based on one or more parameters related to dental restoration.
[000198] In some embodiments, the process comprises validating that the tooth can be prepared according to the surface of the virtual preparation guide.
[000199] In some embodiments, the 3D digital representation of the set of prepared teeth is obtained by scanning the patient's mouth with an intraoral scanning device. The 3D digital representation of the set of prepared teeth can then be viewed, together with the virtual dental preparation guide, as viewed together with the surface of the virtual preparation guide, while the patient is still in the dentist's chair.
[000200] It may be an advantage that the dentist can perform a tooth preparation validation using an intraoral scanning device, simultaneously or concurrently with the preparation procedure. You can scan a region in which you have prepared a tooth, and by comparing the 3D digital representation of the region obtained by scanning that region with the virtual dental preparation guide, the dentist can check whether you have taken enough material from the tooth or whether you need to take more material, and where in the tooth the material needs to be removed. The intraoral scan validation procedure can be an alternative and / or an addition to the use of physical preparation guides.
[000201] In some embodiments, the dental preparation guide is designed so that a drill bit can approach, and come into contact with, the tooth, when the dental preparation guide is placed on the teeth. The bit can have a diameter corresponding to the desired thickness of the restoration in that particular part of the restoration, so that in an area of the tooth, in which, for example, 2 mm of tooth material must be removed, the dental preparation guide provides space for a 2 mm drill.
[000202] In some embodiments, the dental preparation guide is configured to guide a dentist or a dental preparation machine in preparing the tooth.
[000203] For some teeth, such as a molar tooth, the removal of tooth material on the lingual, buccal / labial and / or occlusal surface can result in the margins of the tooth cusp.
[000204] For some restoration materials, such as ceramics, it may be preferred that sharp edges are avoided. In some embodiments, the validation surface of the dental preparation guide is configured so that the surface of the prepared tooth has no sharp edge. This can be achieved by smoothing transitions between, for example, the prepared lingual and occlusal surfaces of the tooth.
[000205] In some embodiments, the process for validating the preparation of a tooth comprises determining the distance between the 3D digital representation of the set of prepared teeth and the virtual validation surface of the virtual dental preparation guide, in one or more locations selected in the tooth surface. In this case, it is considered that the dental preparation guide, virtual or physically, is placed on the tooth, when the distance is measured. That is, the distance can be determined when the dental preparation guide is placed in a target position in relation to the teeth.
[000206] In some cases, the process involves determining a minimum distance, in which the measured distance, between the dental preparation guide and the surface of the prepared tooth, should not be below this minimum distance. The minimum distance may vary across the tooth surface, so that, for example, it is greater near the occlusal surface than near the gum. The minimum distance may depend on the selection of the material of the dental restoration and the aesthetic aspects, such as the requested change in the color of the tooth.
[000207] The distance can be said to be positive when the virtual validation surface is closer to the center of the tooth than the 3D digital representation. In that case, additional preparation (of that part) of the tooth may be necessary.
[000208] The distance can be said to be negative when the 3D digital representation is closer to the center of the tooth than the virtual validation surface. In that case, there is no need for further preparation (of that part) of the tooth.
[000209] The distance can be determined at a specific position on the tooth surface. Very often, the distance varies by the validation surface. The distance can be, for example, positive in some parts of the validation surface and negative in other parts.
[000210] In some embodiments, the process for validating the preparation of a tooth comprises determining the distance between the 3D digital representation of the set of prepared teeth and the virtual validation surface or the virtual dental preparation guide, during a virtual movement along of the insertion direction in the target position of the dental preparation guide.
[000211] In some embodiments, the distance is predetermined as the minimum value (on the specific part of the validation surface), obtained during the virtual movement along the insertion direction to the target position of the dental preparation guide.
[000212] This has the advantage that, when preparing the tooth according to the dental preparation guide, it is guaranteed that the dental restoration can be inserted along the insertion direction in the prepared tooth.
[000213] In some embodiments, viewing the virtual dental preparation guide, together with the 3D digital representation of the set of prepared teeth, comprises using a color coding.
[000214] Color coding has the advantage that visual inspection of the present suitability of the tooth preparation is facilitated, for example, by using a visual display unit, such as a screen.
[000215] In some embodiments, the process for validating the preparation of a tooth comprises visualizing the distance of at least some of the selected location (s) on the surface of the tooth, such as visualizing the distances by using a distance color coding or by distance indication using a numerical representation, for example, the distance measured in millimeters.
[000216] Different color ranges can be used in distance color coding, such as distance color coding in which red indicates a positive distance, so that the tooth needs additional preparation, while blue indicates a negative distance, at which no further processing is required.
[000217] Color coding can be done by identifying the part of the 3D digital representation of the set of prepared teeth corresponding to the prepared tooth, and presenting that part in a different color than the other parts of the 3D digital representation. The other parts can, for example, be displayed in a gray or brownish color, while the prepared tooth is visualized in a light color, such as blue or red, depending on the distance from the surface of the virtual preparation guide.
[000218] In some embodiments, the visualization of the virtual dental preparation guide, together with the 3D digital representation of the set of prepared teeth, comprises a difference map, showing the differences between the surface of the virtual preparation guide and the shape of the tooth in the digital 3D representation of the set of pre-prepared or prepared teeth. The difference map can visualize the difference using a different color coding.
[000219] The advantage of using this difference map and different color coding is that the dentist can immediately see from the visualization which part or parts of the tooth need further preparation.
[000220] In some embodiments, the process comprises enabling and disabling the visualization of the virtual dental preparation guide, so that the visualization of the virtual preparation guide surface, in relation to the 3D digital representation of the prepared teeth, comprises between viewing the representation Digital 3D of the set of prepared teeth only and in combination with the surface of the virtual preparation guide. By enabling and disabling visualization, the dentist can easily assess which part or parts of the prepared tooth need additional preparation.
[000221] In some embodiments, the process comprises enabling and disabling the visualization of the virtual dental preparation guide, so that the visualization of the virtual preparation guide surface, in relation to the 3D digital representation of the pre-prepared teeth, comprises switching between the visualization of the digital 3D representation of the set of pre-prepared teeth only and in combination with the surface of the virtual preparation guide. By enabling and disabling visualization, the dentist can easily assess in which part or parts of the pre-prepared tooth material should be removed in the preparation procedure and how much material should be removed in the different parts of the tooth, even before it has started to remove any tooth material.
[000222] In some embodiments, the process comprises enabling and disabling the visualization of a desired virtual dental restoration, so that a visualization of the desired virtual dental restoration in relation to the 3D digital representation of the set of pre-prepared teeth or prepared teeth, it comprises alternating between visualizing the digital 3D representation of the set of pre-prepared teeth or prepared teeth, and in combination with the desired virtual dental restoration. This provides the dentist with an indication of how well the desired virtual dental restoration is designed for the patient's set of teeth with respect, for example, to the aesthetic appearance of the teeth.
[000223] In some embodiments, the visualization comprises involving the surface of the virtual preparation guide or the virtual validation surface in the 3D digital representation of the set of pre-prepared or prepared teeth.
[000224] In some embodiments, the visualization comprises visualizing the minimum virtual preparation, together with the 3D digital representation of the set of prepared teeth. This provides the dentist with an indication of where the tooth is prepared according to the virtual minimum preparation, and thus how much material needs to be removed in the different parts of the tooth.
[000225] In some embodiments, the virtual dental preparation guide comprises a depth map, showing when material should be removed in the different sections of the tooth, to provide a shape of the prepared tooth, which is acceptable according to the dental preparation guide . The depth map can use depth color coding to see how much tooth material is to be removed. The advantage of using this depth map is that it gives the dentist a direct indication of how much tooth material should be removed from different parts of the tooth.
[000226] In some embodiments, the process of using the dental preparation guide comprises the alignment of the virtual dental preparation guide and the 3D digital representation of the set of prepared teeth.
[000227] In some embodiments, the virtual validation surface is created according to the shape of the desired virtual dental restoration, and, after being created, is connected with the 3D digital representation of the set of prepared teeth. In some embodiments, the desired virtual dental restoration is connected to the 3D digital representation of the set of remaining teeth, and subsequently, the virtual validation surface is formed based on the desired virtual dental restoration.
[000228] When the virtual dental preparation guide is placed in a target position, relative to the 3D digital representation of the set of teeth, the tooth part of the 3D digital representation of the set of teeth can penetrate the virtual validation surface, if the tooth preparation is insufficient. The tooth part of the 3D digital representation can also penetrate the virtual validation surface, during a virtual movement along the insertion direction, if the tooth preparation is insufficient.
[000229] A virtual dental preparation guide can be adjusted during a procedure. The virtual dental preparation guide can be determined from the moment shape of the tooth set, in which at least one tooth has been prepared or at least partially prepared. The difference between, for example, the surface of the target restoration and the moment shape of the set of teeth defines how much space is provided for the dental restoration. This space can be evaluated so that it is possible to decide if there is space for dental restoration. This assessment can be made after each tooth perforation, and the assessment can include comparing the moment shape of the prepared teeth with the virtual validation surface described in this specification.
[000230] In some embodiments, the dental preparation guide is a two-piece device comprising a first and a second part. The first part is formed as a temporary crown and is designed to have an external surface formed to resemble a normal tooth surface, and an internal surface with a shape based on the virtual validation surface. The second part is designed to have an inner surface configured to couple the outer surface of the first part, so that the first and second parts can be releasably connected to form the two-piece dental preparation guide. Once the first and second parts are releasably connected, they can be decoupled after the dental preparation guide is used by the dentist to validate the tooth preparation. The first part can then be attached to the prepared tooth, acting as a temporary restoration, until a final restoration is manufactured.
[000231] A two-piece dental preparation guide to validate the preparation of at least one tooth for a dental restoration is described, said dental preparation guide comprising: - a first part formed as a temporary crown, wherein said first part is designed to have an external surface, formed to resemble a normal tooth surface, and an internal surface, with a shape based on the virtual validation surface; and - a second part designed to have an internal surface, configured to couple the external surface of the first part, where the second part can be releasably connected with the first part, so that the first and second parts form the guide together of dental preparation.
[000232] After being used by the dentist to validate tooth preparation, the first and second parts of the two-piece dental preparation guide can be uncoupled, and the first part can be attached to the prepared tooth, acting as a temporary restoration, until that a final restoration is manufactured. An advantage of this two-piece dental preparation guide is that the part of the dental preparation guide, which is specifically formed according to the prepared tooth, can be reused, and that the dental restoration is easily available when the tooth has been prepared. In prior art dental preparation processes and guides, both a dental preparation guide and a temporary crown must be manufactured.
[000233] A process for generating a dental preparation guide, configured to validate the preparation of at least one tooth in a set of teeth for a dental restoration, is described, said process comprising: a: virtually forming a set of remaining teeth by virtual removal of said at least one tooth from a digital 3D representation of the set of teeth; b: providing virtually a desired dental restoration expressing a desired form of the dental restoration for said at least one tooth, and virtually creating a validation surface based on the desired dental restoration; and c: create virtually the dental preparation guide by combining said validation surface and at least part of the set of remaining teeth.
[000234] A process for generating a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, the said process comprising: a: obtaining a 3D digital representation of a set of prepared teeth and identify the part of the 3D digital representation corresponding to the prepared tooth; b: generate a minimum virtual restoration surface of the prepared tooth part and a minimum necessary thickness of the dental restoration; and c: determine overlaps between the generated virtual minimum restoration surface and the 3D digital representation obtained from a set of prepared teeth.
[000235] A computer program product, comprising a program coding means, is described to make a data processing system perform the process, according to any of the embodiments, when said program coding means runs on the data processing system.
[000236] In some embodiments, the computer program product comprises a computer-readable medium, having stored the program encoding medium therein.
[000237] A non-transitory computer-readable medium is described, storing in it a computer program, in which said computer program is configured to cause computer-assisted generation of dental preparation guide, configured to validate the preparation of a tooth for a dental restoration by executing the process according to any of the embodiments.
[000238] A system for generating a dental preparation guide, configured to validate the preparation of a tooth for a dental restoration, is described, said system comprising: - a scanning device configured to obtain a digital 3D representation of a set of pre-prepared teeth; - a means for providing a desired virtual dental restoration expressing a target form of the dental restoration; and - a means for generating the dental preparation guide of said 3D digital representation of the set of pre-prepared teeth and / or said desired virtual dental restoration, wherein the dental preparation guide is configured to provide a tooth preparation, according to the dental preparation guide, ensure that dental restoration can be done and can be inserted into the prepared tooth.
[000239] In some embodiments, the means for generating comprises a non-transitory computer-readable medium, having one or more computer instructions stored therein, wherein said computer instructions comprise instructions for carrying out the process according to the present invention.
[000240] A system for generating a dental preparation guide, configured to validate the preparation of a tooth for a dental restoration, is described, said system comprising: - a scanning device configured to obtain a digital 3D representation of a set of pre-prepared teeth; - a data processing device configured to generate the dental preparation guide for said digital 3D representation of the set of pre-prepared teeth and / or the desired virtual dental restoration, wherein the dental preparation guide is configured to provide a preparation of the tooth, according to the dental preparation guide, ensure that dental restoration can be done and can be inserted into the prepared tooth, and in which the so-called virtual dental restoration expresses a target form of dental restoration, in which the device The data processing method comprises a non-transitory computer-readable medium, having one or more computer instructions stored therein, wherein said computer instructions comprise instructions for carrying out the process according to the present invention.
[000241] The generated dental preparation guide can be a virtual dental preparation guide, which can be used directly to validate a tooth preparation in a virtual physical medium, and / or which can be used to manufacture a physical dental preparation guide .
[000242] A process for validating a preparation of at least one tooth in a set of prepared teeth is described to determine whether the prepared tooth is capable of accepting a dental restoration, said process comprising: - obtaining a dental preparation guide physicist configured to validate tooth preparation; - have the dental preparation guide in relation to the patient's set of prepared teeth; and - validate, from the physical interaction of the physical dental preparation guide and the set of prepared teeth, if the set of prepared teeth is formed so that it can accept the dental restoration.
[000243] In some embodiments, the physical dental preparation guide is manufactured from the virtual dental preparation guide, in accordance with the present invention.
[000244] A process for validating a tooth preparation in a set of prepared teeth is described to determine whether the prepared tooth is capable of accepting a dental restoration of a desired virtual dental restoration, wherein said process comprises: a: obtain a desired virtual dental restoration for the set of teeth; b: obtain a 3D digital representation of the set of prepared teeth; and c: validate that the prepared tooth from the set of teeth
[000245] standing still is formed so that it can accept dental restoration.
[000246] In some embodiments, the validation comprises visualizing the desired virtual dental restoration together with the 3D digital representation of the set of prepared teeth, so that the validation can be based on said visualization.
[000247] The desired virtual dental restoration may comprise a diagnostic wax mold of the set of teeth.
[000248] A process to validate the preparation of a tooth for a dental restoration is described, said process comprising: - obtaining a virtual dental preparation guide configured to validate the preparation of the tooth; - obtain a 3D digital representation of the set of prepared teeth; and - view the virtual dental preparation guide together with the 3D digital representation of the set of prepared teeth.
[000249] A user interface to generate a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, in which the user interface is configured to: a: obtain a 3D digital representation a set of pre-prepared teeth; b: virtually removing said at least one tooth from the 3D digital representation of a set of pre-prepared teeth, so that a 3D digital representation of a remaining set of teeth is formed; c: providing a desired virtual dental restoration by pressing a desired form of the dental restoration; d: create a virtual validation surface for the dental preparation guide based on the desired virtual dental restoration, where the validation surface is such that the tooth preparation can be validated by the dental preparation guide; and e: create a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining set of teeth.
[000250] A user interface to generate a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, is described, in which the user interface is configured to: - remove at least virtual said a tooth from a 3D digital representation obtained from the set of pre-prepared teeth, so that a digital 3D representation of a set of remaining teeth is formed; - create a virtual validation surface for the dental preparation guide, based on a desired virtual dental restoration provided, expressing a target form of the dental restoration, in which the validation surface is so that the tooth preparation can be validated the dental preparation guide; and - creating a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining teeth set.
[000251] In some embodiments, the user interface is configured to view the 3D digital representation obtained from a set of pre-prepared teeth and the surface of the virtual preparation guide created.
[000252] The visualization can be done sequentially so that at least one of the displayed items is displayed before at least one of the other displayed items. Several visualized items can also be viewed simultaneously, so that, in cases where the created validation surface and the 3D digital representation of the remaining teeth are displayed in a part of the user interface, and the 3D digital representation of the pre-set of teeth -prepared is displayed elsewhere.
[000253] In some embodiments, the user interface is configured to be viewed by an operator using a computer screen and to allow the operator to enter data and make selections, presented on the user interface, through a computer keyboard or a computer mouse.
[000254] In some embodiments, the user interface is configured to view the surface of the virtual preparation guide together with the 3D digital representation of the set of prepared teeth, and the user interface comprises a virtual state change tool to switch between the visualization of the digital 3D representation of the set of prepared teeth only and in combination with the surface of the virtual preparation guide, when activated.
[000255] In some embodiments, the user interface is configured to display the surface of the virtual preparation guide together with the 3D digital representation of the set of pre-prepared teeth, and the user interface comprises a virtual state change tool for switch between viewing the digital 3D representation of the set of prepared teeth only and in combination with the surface of the virtual preparation guide, when activated.
[000256] The user interface can be implemented using a computer system, in which the user interface is visualized using a computer screen showing the different components of the user interface, such as data entry fields and virtual push buttons configured to perform one or more steps of a process according to an embodiment of the invention. Data entry means, such as a computer mouse and a computer keyboard, can be connected to the computer system and used to input data into the user interface and make selections by, for example, compressing said virtual push buttons, using the computer mouse.
[000257] In some embodiments, the user interface is configured to allow an operator to conduct a process in accordance with an embodiment of the invention. Preferably, at least one of the steps of obtaining a 3D digital representation of a set of pre-prepared teeth and forming a digital 3D representation of a set of remaining teeth, by virtual removal of said at least one tooth from the 3D representation digital set of pre-prepared teeth, providing a desired virtual dental restoration expressing a target form of dental restoration, creating a virtual validation surface for the dental preparation guide, based on the desired virtual dental restoration, and creating a surface of the virtual preparation guide by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining teeth set can be performed by the operator using said user interface. In some embodiments, the process steps are performed sequentially and the user interface can be configured to provide a visual representation of the steps to the operator sequentially, so that the user interface sequence is the same as that of the process. In some embodiments, the user interface is configured to simultaneously provide a visual representation of two or more of the steps for the operator.
[000258] The present invention relates to different aspects, including the processes, uses and systems described above and below, and corresponding processes, uses and systems, all generating one or more benefits and advantages, described together with the first mentioned aspect. , and all having one or more embodiments corresponding to the embodiments described together with the first aspect mentioned and / or described in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS
[000259] The objects, aspects and advantages mentioned above and / or additional to the present invention will be further clarified by the detailed non-limiting and illustrative description of the embodiments of the present invention, with reference to the attached drawings, in which:
[000260] Figure 1 shows a flow chart for carrying out the process for generating a dental preparation guide;
[000261] figure 2 shows an example of a flow chart to generate a virtual dental preparation guide and to use it to validate a tooth preparation;
[000262] figure 3 shows a schematic representation of teeth in a patient's jaw and presentations in cross section relating to some of the surfaces involved in generating the surface of the virtual preparation guide;
[000263] figure 4 shows an example of how a 3D digital representation of the set of remaining teeth and a virtual validation surface can be connected;
[000264] figure 5 shows an example of a virtual preparation guide surface;
[000265] figure 6 shows a route for manufacturing the dental preparation guide from the surface of the virtual preparation guide;
[000266] figure 7 shows a route for manufacturing the dental preparation guide from the surface of the virtual preparation guide;
[000267] figure 8 shows a situation in which the insertion direction should preferably be considered;
[000268] figure 9 shows how the insertion direction can be considered when designing the dental preparation guide;
[000269] figure 10 shows snapshots in which the virtual removal of teeth introduces virtual holes in the 3D digital representation of the remaining teeth;
[000270] figure 11 shows an example of an embodiment of the invention for forming a surface of the virtual preparation guide;
[000271] figure 12 shows, by means of a block diagram, a computerized device for generating a dental preparation guide;
[000272] figure 13 shows a schematic representation of a user interface, according to an embodiment of the invention;
[000273] figure 14 shows a flow chart for carrying out the process for generating a dental preparation guide;
[000274] figure 15 shows an exemplary dental preparation guide formed as a two-piece device, with a first part formed as a temporary crown;
[000275] figure 16 shows an example of a dental preparation guide, generated from a 3D digital representation of the set of prepared teeth, and a minimum necessary thickness of the dental restoration; and
[000276] figure 17 shows an example of a tooth preparation, and a dental preparation guide, configured to validate the tooth preparation.
[000277] In the description presented below, reference is made to the attached figures, which show, by way of illustration, how the invention can be practiced.
[000278] In the flowcharts of figures 1, 2 and 14, the vertical dotted line in the center divides the workflows into a part relative to the physical units (left side) and a part relative to the virtual units (right side) in the workflow .
[000279] Figure 17 shows an example of a tooth preparation, and a dental preparation guide, configured to validate the tooth preparation.
[000280] Figure 17a shows a section of a set of 1794 pre-prepared teeth, that is, a set of teeth before preparation, for which the dental preparation guide is configured to validate. The figure to be prepared 1795 and neighboring teeth 1796 are shown in the figure. Also, the dental drill 1798, ready to remove material from the tooth, is prepared in the figure to prepare tooth 1795 to accept a dental restoration. , such as a crown restoration.
[000281] Figure 17b shows the set of prepared teeth 1791, that is, the set of teeth after at least part of the preparation of the tooth has been conducted. The tooth 1783 is then reduced in size, so that the dental restoration, similar in size and shape to the original tooth 1795, can be placed on the prepared tooth. In the illustrated case, the neighboring teeth are not prepared.
[000282] Figure 17c shows the generated dental preparation guide 1799, arranged to validate the preparation of the tooth. In this case, the 1799 dental preparation guide is designed to rest on neighboring teeth 1796. In the illustrated situation, the tooth has to be prepared so that it has a shape that allows the 1799 dental preparation guide to be placed on the prepared tooth 1783 and neighboring teeth 1796, without colliding with the prepared tooth. The dentist can then conclude that the tooth preparation is complete, and that the prepared tooth is ready to accept the dental restoration. If the 1799 dental preparation guide cannot be arranged in contact with both neighboring teeth, due to collisions with the prepared teeth, further processing is necessary.
[000283] Figure 14 shows a flowchart 1400 for implementing the process to generate a dental preparation guide, to validate the preparation of a tooth for a dental restoration.
[000284] In step 1401a, a 3D digital representation of the set of pre-prepared teeth is obtained, for example, by direct intraoral scanning of the set of teeth or by scanning a physical model, or an impression of the set of pre-prepared teeth .
[000285] In step 1401b, the portion of the 3D digital representation corresponding to the tooth or teeth, for which the dental preparation guide is generated, is removed virtually so that a 3D digital representation of a set of remaining teeth is formed.
[000286] In step 1403, a desired virtual dental restoration is created. The desired virtual dental restoration can be created based on a virtual diagnostic wax mold for the set of teeth, in which the virtual diagnostic wax mold expresses a target shape of the desired virtual dental restoration.
[000287] In step 1404, the virtual validation surface is created in the desired virtual dental restoration, and, in step 1405, the virtual preparation guide surface is created by connecting the virtual validation surface and the 3D digital representation surface of the set of remaining teeth.
[000288] Figure 1 shows a flow chart 100 for an embodiment of the process to generate a physical dental preparation guide, to validate the preparation of a tooth.
[000289] In step 101a, a 3D digital representation of the set of pre-prepared teeth is obtained, for example, by direct intraoral scan of teeth, or by scanning a physical model or an impression of the set of pre-prepared teeth.
[000290] In step 101b, the portion of that 3D digital representation corresponding to the tooth or teeth, for which the 3D digital representation is generated, is removed virtually, so that a digital 3D representation of the set of remaining teeth is formed.
[000291] In step 102, a virtual diagnostic wax mold for the set of teeth is designed so that it expresses a target shape of the dental restoration. The virtual diagnostic wax mold is based on one or more aesthetic parameters, which can refer to the shape of the individual teeth, the color of the teeth and / or the relative disposition of the teeth. The material of the dental restoration can be decided based, for example, on patient selection or practical dental aspects, such as size and shape of the tooth or teeth, which will or will be restored. There should be enough space for the dentist to perform the necessary steps in preparing the tooth and to insert the dental restoration into the prepared tooth. The minimum thickness of the restoration material also depends on the desired color change. A major change may require greater thickness.
[000292] The desired virtual dental restoration is created based on the virtual diagnostic wax mold designed in step 103, and, in step 104, the virtual validation surface is created based on the desired virtual dental restoration.
[000293] In step 105, the surface of the virtual preparation guide is created by connecting the virtual validation surface and the surface of the 3D digital representation of the set of remaining teeth.
[000294] In step 106, at least a selected part of the surface of the virtual preparation guide is coated, so that the virtual dental preparation guide comprises an internal coating surface and an external coating surface on the selected part.
[000295] In some cases, the outer coating surface is formed according to the created virtual preparation guide surface, and the coating can be used to define the inner coating surface of the outer surface, that is, the guide surface of virtual preparation. In these cases, an intermediate physical model can be manufactured from the surface of the coated virtual preparation guide, in step 107, using direct digital manufacturing. The physical dental preparation guide is then manufactured in step 108 by forming the material of the dental preparation guide using said intermediate physical model. The material of the dental preparation guide can be formed by vacuum formation in the intermediate physical model.
[000296] In some cases, the inner lining surface is formed according to the dental preparation guide, and the lining can be used to define the outer lining surface of the inner lining surface, that is, of the surface of the lining guide. virtual preparation. In such cases, the physical dental preparation guide is manufactured in step 109 of the coated virtual preparation guide surface using, for example, a 3D print.
[000297] Figure 2 shows an example of a flow chart to generate a virtual dental preparation guide and to use it to validate a tooth preparation. The flowchart contains part 210, relating to the generation of the virtual dental preparation guide, and part 211, to use the virtual dental preparation guide generated to validate the tooth preparation.
[000298] In step 2011, a 3D digital representation of the set of pre-prepared teeth is obtained by direct intraoral scanning of the teeth. A virtual dental preparation guide is then created in step 212 using, for example, steps 102 to 106 of the workflow, described in relation to figure 1, or steps 1401a to 1404, described in relation to figure 14.
[000299] The tooth or teeth are prepared for restoration by scraping the tooth material. The patient's set of teeth is then referred to as a set of prepared teeth.
[000300] In step 2012, the intraoral scanning device is used to scan at least the region of the prepared teeth set, in which the prepared tooth (s) are located, to obtain a digital 3D representation of the prepared teeth set.
[000301] In step 214, the digital 3D representation of the set of prepared teeth and the dental preparation guide are aligned and visualized together in a visual display unit, such as a computer screen.
[000302] Based on the aligned digital 3D representation of the set of prepared teeth and the virtual dental preparation guide, a validation of the tooth preparation is done in step 215, to determine whether additional preparation is necessary.
[000303] If additional preparation is required, the dentist continues the preparation in step 213. A new intraoral scan 2012, alignment 214 and validation 215 are then conducted, and the loop continues until no further preparation of the tooth is required and the dentist selects to follow a next part of the dental procedure.
[000304] The intraoral scanning device can be configured to use focal scanning, in which the 3D digital representation of the scanned teeth is reconstructed from focused images captured at different depths of focus. The focal scanning technique can be done by generating a probe light, and transmitting that probe light to the set of teeth, so that at least part of the set of teeth is illuminated. The light returning from the set of teeth is transmitted to a camera and transformed into an image sensor in the camera by means of an optical system, in which the image sensor comprises an array of sensor elements. The position of the focus plane relative to the set of teeth is varied by means of focusing optics, while the images are obtained from the said arrangement of sensor elements. Based on the images, the focused position (s) of each of several sensor elements of each of several groups of sensor elements can be determined for a sequence of focus plane positions.
[000305] The focused position can be, for example, calculated by determining the amplitude of light oscillation for each of several sensor elements or each of several groups of sensor elements for a range of focus planes. From the focused positions, the digital 3D representation of the set of teeth can be obtained.
[000306] The creation of the dental preparation guide and the use of it can occur in parallel with the preparation of the tooth or teeth, and may, as such, not be part of a treatment in the patient, but be, instead, a process to generate and to use a guide to validate tooth preparation.
[000307] In the text presented above, the process is described in relation to the evaluation of a tooth preparation. The process is of course also suitable for the simultaneous evaluation of the preparation of several teeth.
[000308] Figure 3 shows a schematic representation of teeth in a patient's jaw and a cross-sectional plane in a tooth to be prepared.
[000309] The set of teeth 300 has a tooth 316a, which, for example, is diseased and in need of a dental restoration, such as a crown. The tooth must therefore be prepared so that it is able to accept the crown. The plane in which the cross-sectional view is obtained is defined by line A - B crossing the tooth and the normal line to the occlusal plane of the set of teeth, that is, the plane is perpendicular to the occlusal plane.
[000310] Figures 3b to 9, 11 and 15 to 17 show representations in cross section of the teeth and the dental preparation guide, as seen in the plane defined in figure 3a.
[000311] Figure 3b shows presentations in cross section related to some of the surfaces involved in generating the surface of the virtual preparation guide.
[000312] The tooth part 316b of the digital 3D representation of the set of pre-prepared teeth is virtually removed at a limit, determined by the 3D sectioning flute 315. When the tooth is virtually removed, a virtual hole is introduced in the digital 3D representation of the set of remaining teeth 318.
[000313] In this example, the desired virtual dental restoration is based on a 319 diagnostic wax mold, designed according to, for example, the patient's aesthetic preferences.
[000314] The virtual validation surface 320 is based on a virtual minimum preparation surface, defined by displacement into the diagnostic wax mold 319 and by pushing a part of the displaced surface, which extends beyond the tooth part 316b in the part tooth, to provide that the virtual validation surface follows the tooth surface on that part of the tooth. A virtual preparation line 321 is also illustrated in the figure.
[000315] With the virtual validation surface 320, described by the minimum preparation surface, the surface of the virtual preparation guide can be created by connecting the 3D digital representation of the remaining teeth set 318 and the virtual minimum preparation surface.
[000316] Figure 4 shows an example of how a 3D digital representation of the set of remaining teeth and a virtual validation surface can be connected. A flute of the remaining 3D teeth 4171 was determined based on the 3D sectioning flute seen in figure 3. Since the virtual validation surface 420, which is based on the virtual minimum preparation surface, is smaller than the corresponding part of the representation Digital 3D of the set of pre-prepared teeth, there is a hole between the virtual validation surface 420 and the 3D digital representation of the set of remaining teeth 418.
[000317] The surface of the virtual preparation guide is created by connecting the virtual validation surface 420 and the 3D digital representation of the set of remaining teeth 418. These surfaces are connected by creating a connecting surface 422, which extends from the flute of the remaining 3D teeth 4171 for a flute on the 3D 423 validation surface. In this case, the flute on the 3D validation surface 423 is arranged above the virtual preparation line 421, but can, in principle, be arranged anywhere on the surface of virtual validation, as substantially along the virtual preparation line 421.
[000318] The connecting surface 422 can be created in a tracing process.
[000319] The flute of the remaining 4171 3D teeth can be determined by modifying the 3D sectioning flute, which was defined in relation to the 3D digital representation of the set of pre-prepared teeth. In some embodiments, the modification is aided by visualizing the 3D sectioning flute in relation to the surface of a virtually removed tooth or a tooth of the desired virtual dental restoration. When viewed in relation to a virtually removed tooth, any interproximal holes in the virtually removed tooth may have been previously closed, using, for example, curvature-based algorithms.
[000320] To provide a waterproof virtual preparation guide surface, additional hole closure may be required. This can be done using curvature-based hole closing algorithms.
[000321] Figure 5 shows an example of a virtual preparation guide surface.
[000322] The surface of the virtual preparation guide 524, illustrated in this figure, is created from the virtual validation surface, the connection surface and the 3D digital representation of the remaining teeth set, as seen in figure 4. The surface of the preparation guide virtual preparation 524 is, in this case, aligned with a 3D digital representation of the set of prepared teeth 525.
[000323] Due to the fluted location of the 3D validation surface above the virtual preparation line in figure 4, a security zone 526 is provided in the preparation line, providing some space for the dentist to handle, such as adjusting the effective position of the preparation line during the dental procedure.
[000324] Figure 6 shows a route for manufacturing the dental preparation guide from the surface of the virtual preparation guide. In this embodiment, the physical dental preparation guide is manufactured directly from the virtual dental preparation guide.
[000325] The surface of the virtual preparation guide 624, representing an internal coating surface, is displaced outward to provide an external coating surface 627. Based on the surface of the coated virtual preparation guide, a physical dental preparation guide 628 it can be manufactured using direct digital manufacturing, such as 3D printing. The surface of the dental preparation guide, facing the set of teeth, is formed according to the surface of the virtual preparation guide.
[000326] In the context of the present invention, the phrase "the surface is displaced outward" corresponds to the displacement of the surface away from the position in which the teeth are located, when the dental preparation guide is arranged in relation to the patient's teeth.
[000327] Figure 7 shows a route for manufacturing the dental preparation guide from the surface of the virtual preparation guide. In this embodiment, the physical dental preparation guide is manufactured using an intermediate physical model, formed based on the virtual dental preparation guide.
[000328] The surface of the virtual preparation guide 724, representing an outer coating surface, is displaced inward to provide an internal coating surface 729. Based on the surface of the coated virtual preparation guide, an intermediate physical model 730 can be manufactured using direct digital manufacturing, such as 3D printing. In the context of the present invention, the phrase "the surface is displaced inward" corresponds to the displacement of the surface to the position in which the teeth are located, when the dental preparation guide is arranged in relation to the patient's teeth.
[000329] The material of the dental preparation guide 731 is then formed according to the intermediate physical model 730 by, for example, vacuum formation of the intermediate physical material 730. The material of the dental preparation guide 731 is then separated from the intermediate model. 730, to provide the physical dental preparation guide 728, wherein the surface facing the set of teeth is formed according to the surface of the virtual preparation guide.
[000330] Figure 8 shows a situation in which the insertion direction should preferably be considered to generate a dental preparation guide, which also considers that the dental restoration moves along a route, when it is arranged in relation to to the patient's set of teeth.
[000331] A dental restoration 832 is moved along a route determined by the direction of insertion 8833 towards its target position, relative to the set of prepared teeth 834. The inner surface 835 of dental restoration 832 is equal to the corresponding part of the set of prepared teeth.
[000332] Lines 836 indicate the outline of a marginal line 837 of the dental restoration, when the dental restoration is moved along the route determined by the insertion direction 833. One of these lines, cut by the set of prepared teeth 834, shows that a collision between the set of prepared teeth 834 and the cervical portion of the dental restoration will prevent the dental restoration 832 from being placed in the target position unless the 838 region is removed. That is, the surface of the virtual preparation guide can be formed to ensure that if the tooth is prepared according to the surface of the virtual preparation guide, the 832 dental restoration can be moved to the target position without any collisions.
[000333] Figure 9 shows how the insertion direction can be considered when designing the dental preparation guide. Instead of using an approach in which the dental restoration is trimmed to compensate for the insertion direction, the dental preparation guide is trimmed.
[000334] Figure 9a shows the surface of the virtual preparation guide 920, which is intercepted by one of the routes 9361, which are arranged to pass through the virtual preparation line 921. In this case, the routes 9361 are arranged at an angle of 5 degrees relative to the direction of insertion 933, to provide that the prepared tooth is pointed. In the illustrated situation, narrowing is only necessary on the route that cuts through the 920 virtual validation surface.
[000335] To consider the insertion direction 933 (and, in this example, also the narrowing angle), the virtual validation surface 920 is trimmed so that the surface of the intercepted part is aligned with the route that intercepts it, thus , removing the region that blocks the route of the cervical part of the dental restoration. The trimmed virtual validation surface 930 is seen in figure 9b.
[000336] The trimmed virtual validation surface 920 can then be linked to the 3D digital representation of the set of pre-prepared teeth 918 in the flute of the remaining 3D teeth 9171, to provide the surface of the virtual preparation guide, using, for example, tracing as described above.
[000337] Figure 9c then shows the situation after the insertion direction has been taken into account when designing the virtual validation surface, and therefore the surface of the virtual preparation guide.
[000338] Then, dental restoration 932 can be moved along route 936, determined by the direction of insertion 933 towards its target position, relative to the set of prepared teeth 934, without being blocked by the tooth material.
[000339] An insignificant angle is seen between route 936 and the part of the set of prepared teeth 934, corresponding to the trimmed part of the virtual validation surface. This is caused by the narrowing angle.
[000340] Figure 10 shows snapshots in which the virtual removal of teeth introduces virtual holes in the 3D digital representation of the 3D sectioning cannulas of the remaining teeth 1017, which are defined in relation to the 3D digital representation of the set of pre-prepared teeth. 1037, so that 4 teeth can be removed virtually. The 3D 1017 sectioning flutes can be automatically defined, for example, by extracting the limits of the teeth part of the digital 3D representation of the set of pre-prepared teeth.
[000341] When the teeth are virtually removed, virtual holes appear in the 3D digital representation of the remaining 1018 teeth set. The virtual holes include four virtual gingival holes 1038, and interproximal holes 1039 in the parts of the 3D digital representation of the corresponding remaining teeth set. to neighboring teeth. In that case, there is no limit between each interproximal hole and the neighboring gingival hole.
[000342] A virtual hole can be closed by a virtual replacement surface or closed by virtual gingival and virtual interproximal surfaces.
[000343] When a virtual hole is closed by using a virtual replacement surface, the interproximal sections of the flute of the remaining 3D teeth can be defined in relation to that virtual replacement surface. The flute of the remaining 3D teeth can be arranged to divide a part of the virtual replacement surface into a virtual gingival surface and a virtual interproximal surface.
[000344] Figure 11 shows how a virtual preparation guide surface, with a virtual replacement surface according to the diagnostic wax mold, can be created.
[000345] In figure 11a, a virtual hole, in the 3D digital representation of the set of remaining teeth 1118, is connected by a flap of the remaining 3D teeth 11171. The flute of the remaining 3D teeth can be determined from a 3D sectioning flute, such as such as the 3D 1017 sectioning flute, shown in figure 10.
[000346] In figure 11b, a virtual replacement surface 1140 is connected to the 3D digital representation of the remaining teeth set 1118, in the flute of the remaining 3D teeth 11171, so that the virtual hole in the 3D digital representation of the remaining teeth set 1118 closed.
[000347] In figure 11c, a desired virtual dental restoration 1141, defined from a diagnostic wax mold, is aligned with the 3D digital representation of the remaining teeth set 1118, so that it is intercepted by the part corresponding to the virtual replacement surface. The virtual replacement surface can, in this case, be considered to be the part of the 3D digital representations 1141 arranged above the 3D digital representation of the set of remaining teeth 1118.
[000348] The surface of the virtual preparation guide 1124 can then be created by a Boolean addition of the desired virtual dental restoration 1141 and the 3D digital representation of the remaining tooth set 1118. The surface of the resulting virtual preparation guide 1124 is seen in the figure 11d.
[000349] Alternatively to the connection of the virtual replacement surface to the 3D digital representation of the set of remaining teeth, the interproximal hole can be, at least partially, closed by a virtual interproximal surface, while the gingival hole can be closed by a preparation of virtual tooth or virtual gingival, depending on whether a crown or pontic will be placed at the location of the gingival hole. The surface of the virtual preparation guide can then be created by a Boolean addition of the 3D digital representation of the set of remaining teeth and the preparation of the virtual tooth or the virtual gingival. The boundary, between the virtual interproximal surface and the virtual gingival or virtual tooth preparation, can be used to define the flute of the remaining 3D teeth.
[000350] Figure 12 shows by means of a block diagram a system for generating a dental preparation guide, according to an embodiment of the present invention. The system 1250 comprises a computerized device 1251, comprising a computer readable medium 1252 and a processor 1253. The system further comprises a visual display unit 1256, a computer keyboard 1254 and a computer mouse 1255 for entering data and activating virtual buttons visualized on the 1256 visual display unit. The 1256 visual display unit can be, for example, a computer screen. The computerized device 1251 is capable of receiving a 3D digital representation of the patient's tooth set from a 1257 scanning device, so that the TRIOS intraoral scanning device, manufactured by 3shape A / S, or capable of receiving scanning data from a scanning device and form a 3D digital representation of the patient's set of teeth, based on this scanning data. The 3D digital representation can be a set of pre-prepared or prepared teeth. The received or formed 3D digital representation can be stored in the computer-readable medium 1252 and provided to the 1253 processor. The 1253 processor is configured to virtually remove said at least one tooth from the 3D digital representation of the set of pre-prepared teeth, so that a 3D digital representation of a set of remaining teeth is formed. This can be done based on a 3D sectioning flute defined in relation to the 3D digital representation of the pre-prepared teeth, for example, by the operator using the computer mouse to mark relevant positions in the 3D digital representation of the pre-prepared teeth. A desired virtual dental restoration, expressing a target form of dental restoration, can be provided to the 1253 processor from an external source or from the 1252 computer-readable medium. The 1253 processor is further configured to: create a virtual validation surface for the guide dental preparation, based on the desired virtual dental restoration, where the validation surface is such that the tooth preparation can be validated by the dental preparation guide; and creating a virtual preparation guide surface by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the set of remaining teeth. In addition to the creation of the virtual validation surface and / or the virtual preparation guide surface, one or more options can be presented to the operator, such as connecting the virtual validation surface to the digital 3D representation of the set of remaining teeth using a Boolean addition, or by creating a connecting surface by stroke. The options can be presented in a user interface, visualized on the visual display unit 1256.
[000351] In some cases, the 1253 processor is further configured to coat at least a selected part of the surface of the virtual preparation guide, so that the virtual dental preparation guide comprises an internal coating surface and an external coating surface on the selected part. The system has a 1258 unit to transmit the surface of the coated virtual preparation guide to, for example, a computer-aided manufacturing device (CAM) 1259, to manufacture the dental preparation guide or to manufacture an intermediate physical model, of which the dental preparation guide can be formed by vacuum formation, or another computerized system, for example, located in a lamination center, in which the dental preparation guide or the intermediate physical model is manufactured. The unit for transmitting the virtual 3D model can be a wired or wireless connection.
[000352] The scan of the patient's set of teeth, using the 1257 scanning device, is most often conducted in the dentist's office. The design and manufacture of the dental preparation guide can be carried out in the dentist's office or in a dental laboratory. In this case, the 3D digital representation of the patient's set of pre-prepared teeth can be provided by an Internet connection, between the dentist and the dental laboratory.
[000353] Figure 13 shows a schematic representation of a user interface, according to an embodiment of the invention.
[000354] The figure shows a first part 1371 of the 1370 user interface, in which cross-sectional views of different surfaces used in the design of the dental preparation guide are displayed. In the illustrated example, the virtual validation surface, the 3D digital representation of the remaining teeth set, the virtual preparation line, the 3D remaining teeth flute and the 3D validation surface flume in figure 4 are seen in the first part .
[000355] The second part 1372 of the user interface comprises a data entry section 1374, for entering data relating to, for example, whether the virtual validation surface will be connected by a Boolean addition or by a surface created by a process of layout. A 1373 virtual push button, which is configured to provide the virtual preparation guide surface, is created by combining the virtual validation surface and at least part of the surface of the 3D digital representation of the remaining tooth set, based on the data entered in the 1374 data entry section.
[000356] The user interface can be visualized on a visual display unit, such as a computer screen, which is part of a system configured to implement the process according to the present invention. The user interface is also configured to conduct at least some of the other steps in the process, such as by virtual removal of at least one tooth from the 3D digital representation of the set of pre-prepared teeth, when forming the 3D digital representation of a set of remaining teeth. For these steps, the virtual push buttons and the data entry sections, provided in the second part 1372, may differ from those provided when connecting the virtual surface.
[000357] Figure 15 shows an exemplary dental preparation guide formed as a two-piece device, with a first part formed as a temporary crown.
[000358] The two-piece dental preparation guide 1580, illustrated in figure 15a, has a first part 1581 and a second part 1582, where the second part 1582 is designed to have an inner surface configured to couple the outer surface of the first part 1581, and the second part 1582 can be arranged in relation to the first part 1581, so that the first and second parts form together the dental preparation guide 1580. When the two-piece dental preparation guide 1580 is arranged in relation to the set of the patient's tooth, the inner surface of the first part 1581 faces the prepared tooth 1583 and the second part contacts gum 1584 on the prepared tooth.
[000359] Figure 15b shows the first part 1581, formed as a temporary crown and which is designed to have an external surface 15812, formed to resemble a normal tooth surface, and an internal surface 15812, with a shape based on the surface of virtual validation, so that the first part can validate the preparation of the tooth.
[000360] Figure 15c shows the second part 1582 with its inner surface 15822a, 15822b and the outer surface 15821. The inner surface has a part 15822a, configured to couple the outer surface of the first part of the dental preparation guide, and a second part 15822b, configured to contact the gingiva on the prepared tooth. The first part 15822a provides that the first and second parts of the dental preparation guide can come together and be handled as a cohesive unit, while the second part 15822b ensures that the dental preparation guide 1580 can be correctly arranged relative to the prepared tooth.
[000361] When used to validate tooth preparation, the two-piece dental preparation guide is operated as a cohesive unit, where the inner surface 15812 of the first part 1581 of the dental restoration is used for validation. When the dentist is satisfied with the preparation of the tooth, the first part 1581 and the second part 1582 are decoupled and the first part 1581 can be temporarily attached to the prepared tooth and act as a temporary crown, while the final restoration is manufactured on the basis of , for example, in a sweep of the set of prepared teeth.
[000362] Figure 16 shows an example of a dental preparation guide, generated from the 3D digital representation of the set of prepared teeth and a minimum necessary thickness of the dental restoration.
[000363] The 3D digital representation obtained from a set of prepared teeth 1691 comprises a part 1683, corresponding to the prepared tooth. Based on the prepared tooth part 1683 and a minimum necessary thickness of the dental restoration, a virtual minimum rest surface 1690 is generated. This surface marks the surface of the smallest dental preparation, which can be made to satisfy the requirements, for example, of mechanical stability or color of the dental restoration, when arranged on the prepared tooth in its moment form. Any overlays 1692, between the generated virtual minimum restoration surface 1690 and the 3D digital representation obtained from the set of prepared teeth 1691, can be determined and the dentist can assess whether the overlap is very large or whether a small part of the neighboring teeth can be scraped to provide the space needed for a dental restoration, manufactured according to the virtual minimum restoration surface.
[000364] 1692 overlays can, for example, be viewed on a user interface by color coding, where, for example, red is used to identify the overlapping regions in the 3D digital representation of the set of prepared teeth .
[000365] If the dentist decides what further processing is necessary, remove more tooth material and repeat the process, until the overlap is removed or reduced to an insignificant size.
[000366] Although some embodiments have been described in detail, the invention is not limited to them, but can also be represented in other ways within the scope of the object defined in the claims presented below. In particular, it should be understood that other embodiments can be used and functional and structural modifications can be made, without departing from the scope of the present invention.
[000367] In device claims enumerating multiple media, many of these media can be represented by one and the same piece of hardware. The mere fact that certain measures are listed in mutually different dependent claims, or described in different embodiments, does not indicate that a combination of these measures cannot be used to advantage.
[000368] A claim may refer to any of the preceding claims, and "any" is understood to mean "any one or more" of the preceding claims.
[000369] It should be emphasized that the term "comprises / comprising", when used in this specification, is considered to specify the presence of aspects, integers, steps or components indicated, but does not eliminate the presence or addition of one or more of these aspects, whole numbers, steps, components or their groups.
[000370] The aspects of the process described above and below can be implemented in software and conducted in a data processing system, or other means of data processing, caused by the execution of executable instructions on a computer. Instructions can be a means of encoding programs loaded into memory, such as RAM, a storage medium, or another computer over a computer network. Alternatively, the described aspects can be implemented by a set of connected circuits, instead of software or in combination with software.

权利要求:
Claims (20)
[0001]
1. Process for generating a dental preparation guide, configured to validate the preparation of at least one tooth for a dental restoration, said process comprising: a: obtaining (101a, 1401a) a 3D digital representation of a set of pre-teeth prepared (1794); characterized by the fact that: b: remove virtually (101b, 1401b) said at least one tooth from the 3D digital representation of the set of pre-prepared teeth (1794), so that a digital 3D representation of a remaining set of teeth (318 , 418, 918, 1018, 1118) is formed; c: obtaining (102, 103, 1403) a desired virtual dental restoration (1141) expressing a desired form of the dental restoration (832, 932); d: create (104, 1404) a virtual validation surface (320, 420, 920) for the dental preparation guide (1799) based on the desired virtual dental restoration (1141), where the validation surface is such that the tooth preparation can be validated by the dental preparation guide (1799); ee: create (105, 1405) a virtual preparation guide surface (524, 624, 724, 1124) by combining the virtual validation surface (320, 420, 920) and at least part of the surface of the 3D digital representation of the remaining set of teeth (318, 418, 918, 1018, 1118).
[0002]
2. Process, according to claim 1, characterized by the fact that the method comprises creating a virtual replacement surface (1140) configured to close at least partially a virtual hole (1038, 1039) defined in the 3D digital representation of the set of remaining teeth (318, 418, 918, 1018, 1118) when virtual removal of at least one tooth.
[0003]
3. Process according to claim 2, characterized by the fact that the virtual replacement surface (1140) comprises a virtual gingival surface configured to close a gingival part (1038) of the virtual hole (1038, 1039).
[0004]
4. Process according to claim 2 or 3, characterized by the fact that the virtual substitution surface (1140) comprises a virtual interproximal surface configured to close an interproximal part (1039) of the virtual hole (1038, 1039).
[0005]
5. Process according to any one of claims 2 to 4, characterized by the fact that the method comprises making the virtual replacement surface (1140) part of the 3D digital representation of the set of remaining teeth (318, 418, 918, 1018 , 1118).
[0006]
6. Process according to any one of claims 1 to 5, characterized in that the method comprises creating a virtual minimum preparation surface.
[0007]
7. Process according to claim 6, characterized by the fact that the minimum virtual preparation surface of the tooth is determined from the desired virtual dental restoration (1141).
[0008]
8. Process according to claim 6 or 7, characterized by the fact that the virtual validation surface (320, 420, 920) is based on the virtual minimum preparation surface.
[0009]
9. Process according to claim 8, characterized by the fact that the surface of the virtual preparation guide (524, 624, 724, 1124) is created by virtual connection of the virtual minimum preparation surface and the digital 3D representation of the set of remaining teeth (318, 418, 918, 1018, 1118).
[0010]
10. Process according to any one of claims 1 to 9, characterized in that the surface of the virtual preparation guide (524, 624, 724, 1124) is, at least in part, created by a Boolean addition of the representation Digital 3D of the set of remaining teeth (318, 418, 918, 1018, 1118) and the virtual validation surface (320, 420, 920).
[0011]
11. Process according to any one of claims 1 to 10, characterized by the fact that the method comprises generating a connection surface (422) configured to connect the virtual validation surface (320, 420, 920) and the 3D representation of the set of remaining teeth (318, 418, 918, 1018, 1118).
[0012]
12. Process according to any one of claims 1 to 11, characterized in that the method comprises generating a virtual dental preparation guide from the virtual preparation guide surface (524, 624, 724, 1124).
[0013]
13. Process according to claim 12, characterized in that the method comprises making a physical dental preparation guide (628, 728) from the virtual dental preparation guide using direct digital fabrication.
[0014]
14. Process according to claim 13, characterized by the fact that manufacturing the physical dental preparation guide (628, 728) comprises manufacturing an intermediate physical model (730) from the virtual dental preparation guide and modeling the material of the physical dental preparation guide using said intermediate physical model.
[0015]
15. Process according to any one of claims 12 to 14, characterized in that generating the virtual dental preparation guide comprises covering with at least a part of the virtual dental preparation guide (524, 624, 724, 1124 ) selected so that the virtual dental preparation guide comprises an inner covering surface (729) and an outer covering surface on the selected part.
[0016]
16. Process according to claim 15, characterized by the fact that the outer covering surface is modeled according to the virtual preparation guide surface (524, 624, 724, 1124) created, and the covering defines the surface of inner coverage from the outer covering surface.
[0017]
17. Process according to any one of claims 12 to 16, characterized in that the inner covering surface (729) is formed according to the surface of the virtual preparation guide (524, 624, 724, 1124) created , and the cover defines an outer covering surface from the inner covering surface (729).
[0018]
18. Process according to any one of claims 1 to 17, characterized by the fact that the dental preparation guide is configured to be used in relation to a first region and a second region of the set of teeth, wherein said the first region comprises teeth relating to dental restoration, and said second region comprises at least one additional tooth, wherein the second region is used to correctly align the dental preparation guide with respect to the set of teeth.
[0019]
19. Process according to any one of claims 12 to 18, characterized in that at least one opening is defined in the virtual dental preparation guide so that when the manufactured dental preparation guide (628, 728) is arranged in Regarding the patient's set of teeth, the opening provides access to an area below the dental preparation guide (628, 728).
[0020]
20. Process according to any one of claims 1 to 19, characterized in that the dental preparation guide (1580) is a two-piece device, comprising a first and a second part (1581, 1582), in which : the first part (1581) is formed as a temporary crown and is designed to have an outer surface (15811), formed to resemble a normal tooth surface, and an inner surface (15812), with a shape based on the surface virtual validation; and the second part (1582) is designed to have an inner surface (15822a, 15822b) configured to couple the outer surface (15811) of the first part (1581) so that the first and second parts (1581, 1582) can be connected reliably to form the two-piece dental preparation guide (1580).

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JP2019018044A|2019-02-07|

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法律状态:
2018-12-04| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2020-03-31| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-07-21| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2021-02-02| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 26/11/2012, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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申请号 | 申请日 | 专利标题

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US201161564191P| true| 2011-11-28|2011-11-28|

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US61/564,191|2011-11-28|

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DKPA201100925|2011-11-28|

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DKPA201100925|2011-11-28|

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PCT/EP2012/073605|WO2013079437A2|2011-11-28|2012-11-26|Dental preparation guide|

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