WORKING MODEL TO PERFORM A DENTAL PROSTHESIS FOR A TOOTH STUMP, AND METHOD TO MAKE THE WORKING MODEL

Abstract

The invention relates to a working model to perform a dental prosthesis for a tooth stump, comprising a model mandible with teeth made from resin by means of 3D printing and a detachable model tooth stump. The model tooth stump comprises a main body made from resin by means of 3D printing and a rigid insert introduced in a housing formed in said main body. First fixing means comprised in the rigid insert cooperate with second fixing means, passing through the through holes made in the model mandible with teeth, for integrally attaching the model tooth stump to the model mandible with teeth in a detachable manner.

Claims

1. A working model to perform a dental prosthesis for a tooth stump, said working model comprising: a model mandible with teeth, made from resin by means of 3D printing, comprising at least one toothless space, corresponding to a missing tooth in said model mandible with teeth, and at least one cavity facing said toothless space; a model tooth stump which is placed in said toothless space and which is detachably coupled to said model mandible with teeth, said model tooth stump comprising a first end which is detachably introduced in said cavity and a second end extending from said first end and being in the form of a tooth stump; wherein said model tooth stump comprises at least a first fixing means cooperating with a complementary second fixing means for integrally attaching said model tooth stump to said model mandible with teeth in a detachable manner when said first end is introduced in said cavity; said model mandible with teeth comprises at least one straight through hole which is aligned with said first fixing means; and said second fixing means passes through said through hole in order to cooperate with said first fixing means; wherein said model tooth stump comprises a main body made from resin by means of 3D printing and comprising said first end and said second end, and a rigid insert which comprises said at least first fixing means, said rigid insert being introduced in a housing formed at said first end in the main body, and said rigid insert being integrally attached to said main body, and in that said rigid insert comprises two of said first fixing means and said model mandible with teeth comprises two of said through holes, each of them being aligned with one of said first fixing means in the rigid insert, said through holes in the model mandible with teeth being arranged such that the axis of a first through hole is in the apical-coronal direction (Z) and the axis of a second through hole is in a direction other than said apical-coronal direction (Z).

2. The working model according to claim 1, wherein said rigid insert is metallic.

3. The working model according to claim 1, wherein the axis of said second through hole in the model mandible with teeth is in the vestibular-lingual direction (Y).

4. The working model according to claim 1, wherein first fixing means is a threaded hole in said rigid insert, and said second fixing means is a screw passing through said through hole of the model mandible with teeth and threaded into said threaded hole of the rigid insert.

5. The working model according to claim 1, wherein said first fixing means of the rigid insert is positioned inside said housing when said rigid insert is introduced in said housing, and said main body comprises at least one straight through hole aligned with said through hole of the model mandible with teeth and with said first fixing means in the rigid insert, such that said second fixing means passes through said through hole of the model mandible with teeth and through said through hole of the main body in order to cooperate with said first fixing means in said rigid insert.

6. The working model according to claim 5, wherein said rigid insert is introduced completely in said housing, such that said rigid insert does not protrude from said housing.

7. The working model according to claim 1, wherein said housing is a hollow formed in said main body such that said rigid insert is introduced in said housing from said first end by translation in a direction corresponding to the apical-coronal direction (Z) when said first end of the model tooth stump is introduced in said cavity.

8. The working model according to claim 1, wherein rigid insert has a complementary shape with respect to the shape of said housing in the main body, such that said rigid insert is snugly introduced in said housing and said complementary shape prevents the rotation of said rigid insert with respect to said housing.

9. The working model according to claim 1, wherein said rigid insert has a cylindrical shape with a planar side face, and said housing has a cylindrical shape with a planar side face, complementary to the shape of said rigid insert.

10. The working model according to claim 1, wherein said rigid insert is integrally attached to said main body by means of an adhesive.

11. A method to make the working model according to claim 1, comprising the following steps: performing a scan of all or part of a patient's mandible with teeth, said all or part comprising at least one tooth stump, obtaining as a result of said scan at least one original data set defining the geometry of said all or part of the mandible with teeth; creating, from said at least one original data set, a first processed data set defining the geometry of said model mandible with teeth, including said toothless space, said cavity, and said two through holes, and a second processed data set defining the geometry of said main body of the model tooth stump, including said housing and, where appropriate, said through hole; such that the assembly formed by said model mandible with teeth and said main body of the model tooth stump, when said first end is introduced in said cavity, has a geometry corresponding to the geometry of said all or part of the mandible with teeth defined in said at least one original data set; manufacturing said model mandible with teeth from resin by means of 3D printing from said first processed data set; manufacturing said main body from resin by means of 3D printing from said second processed data set; supplying said rigid insert, introducing it in said housing of the main body, and integrally attaching it to said main body; supplying said at least a second fixing means.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The advantages and features of the invention are apparent from the following description in which a preferred embodiment of the invention is described in a non-limiting manner with respect to the scope of the main claim in reference to the figures.

[0034] FIG. 1 is an exploded perspective view showing a model mandible with teeth, a model tooth stump, and second fixing means in the form of screws.

[0035] FIG. 2 is a perspective view similar to FIG. 1 but with the parts assembled together.

[0036] FIG. 3 is a partially sectioned side view of the model mandible with teeth.

[0037] FIG. 4 is a view similar to FIG. 3, with the model tooth stump coupled to the model mandible with teeth and integrally attached to same by the first and second fixing means in the form of threaded holes and screws.

[0038] FIG. 5 is an exploded perspective view of the model tooth stump formed by the main body and the rigid insert.

[0039] FIG. 6 is a bottom front perspective view of the model mandible with teeth.

[0040] FIGS. 7, 8, and 9 are a perspective view, a side view, and a partially sectioned side view, respectively, of the model tooth stump formed by the main body and the rigid insert introduced in the housing.

[0041] FIGS. 10, 11, and 12 are a sectioned side view, a sectioned front view, and a sectioned bottom view, respectively, of the main body.

[0042] FIGS. 13, 14, 15, and 16 are a side view, a sectioned side view, a perspective view, and a bottom view, respectively, of the rigid insert.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0043] The working model depicted in the figures is used in a laboratory to perform a dental prosthesis for a tooth stump and partially reproduces a patient's mandible, including the teeth and a tooth stump. The working model is formed by two main parts: a model mandible 1 with teeth and a model tooth stump 4 which is detachably coupled to said model mandible 1 with teeth. FIG. 2 shows these two parts 1 and 4 coupled to one another.

[0044] As can be seen in FIGS. 1-3 and 6, the model mandible 1 with teeth comprises the teeth, a toothless space 2 corresponding to a missing tooth in the model mandible 1 with teeth, and a cavity 3 facing said toothless space 2. A straight through hole 10a opening into the cavity 3 and having its axis in the apical-coronal direction Z is formed on the lower face of the model mandible 1 with teeth. Another straight through hole 10b opening into the cavity 3 and having its axis in the vestibular-lingual direction Y is formed on the front face of the model mandible 1 with teeth. Both through holes 10a, 10b have a first outer segment followed by a second inner segment having a smaller diameter than the first outer segment. The difference in diameter between these two segments forms a support shoulder for the head of screws constituting second fixing means 9a, 9b, as will be described below. The model mandible 1 with teeth is a monoblock piece of resin manufactured by means of 3D printing. For example, for the 3D printing a 3D printer with SLA (stereolithography) technology is used, and the resin is a photosensitive resin that hardens when subjected to ultraviolet light.

[0045] As can be seen in FIGS. 5 and 7-9, the model tooth stump 4 is formed by a main body 5 and a rigid insert 6 introduced in a housing 7 formed in said main body 5.

[0046] The main body 5 is a monoblock piece of resin manufactured by means of 3D printing. Preferably, the main body 5 is manufactured with the same 3D printer and with the same resin as the model mandible 1 with teeth. The main body 5 forms a first end 4a of the model tooth stump 4, which is detachably introduced in the cavity 3 of the model mandible 1 with teeth, and a second end 4b extending from said first end 4a and being in the form of a tooth stump, corresponding to the real tooth stump in the patient's mandible. The first end 4a has an outer shape corresponding to the inner shape of the cavity 3, such that it fits snugly therein. As shown in FIGS. 10-12, the housing 7 in the main body 5 is a hollow which is formed at the first end 4a and opens into the lower face of said first end 4a, opposite the second end 4b. The housing 7 has a cylindrical shape with a planar side face 13. The central axis of this cylindrical shape has a direction corresponding to the apical-coronal direction Z when the first end 4a is introduced in the cavity 3. The main body 5 further comprises, in a front wall, a straight through hole 11b which opens into the housing 7 and is aligned with the through hole 10b of the model mandible 1 with teeth when the first end 4a is introduced in the cavity 3.

[0047] The rigid insert 6 is a monoblock piece, preferably made from metal. For example, the rigid insert 6 is made from steel. As can be seen in FIGS. 13-16, the rigid insert 6 has a cylindrical shape with a planar wall 12. The shape of the rigid insert 6 is complementary to the shape of the housing 7 in the main body 5, such that said rigid insert 6 is snugly introduced in said housing 7 by translation in the direction of the axis of the cylindrical shape of the housing 7. The complementary planar faces 12 and 13 prevent the rotation of the rigid insert 6 with respect to the housing 7. In this embodiment, the rigid insert 6 comprises two first fixing means 8a, 8b which are each a threaded hole. A first fixing means 8a is a threaded hole open on the lower face of the rigid insert 6, coaxial with the axis of the cylindrical shape of said insert. The other first fixing means 8b is a threaded hole open on the side cylindrical face of the rigid insert 6, having an axis perpendicular to the axis of the cylindrical shape of said insert.

[0048] As can be seen in FIGS. 4 and 9, the rigid insert 6 is introduced completely in the housing 7, such that it does not protrude from same. The first fixing means 8b, which is a threaded hole in this case, is aligned with the through hole 11b of the first body 5. The rigid insert 6 introduced in the housing 7 is integrally attached to the main body 5 by means of an adhesive arranged in an interstitial space between the outer wall of said rigid insert 6 and the wall of the housing 7. A contact adhesive in liquid or gel form, for example, can be used.

[0049] As seen in FIG. 4, when the first end 4a of the model tooth stump 4 is introduced in the cavity 3, each of the two first fixing means 8a, 8b of the rigid insert 6, which are threaded holes in this case, is aligned with one of the through holes 10a, 10b of the model mandible 1 with teeth. Furthermore, the first fixing means 8b and the through hole 10b are aligned with the through hole 11b of the main body 5.

[0050] Two second fixing means 9a, 9b cooperating respectively with the two first fixing means 8a, 8b are used for integrally attaching the model tooth stump 4 to the model mandible 1 with teeth in a detachable manner when the first end 4a is introduced in the cavity 3. In the depicted example, the two second fixing means 9a, 9b are screws which are threaded into the threaded holes of the rigid insert 6 constituting the first fixing means 8a, 8b. Each second fixing means 9a, 9b in the form of a screw is introduced from outside the model mandible 1 with teeth and passes through one of the through holes 10a, 10b of said model. The second fixing means 9b in the form of a screw also passes through the through hole 11b of the main body 5.

[0051] The described working model is obtained by means of the method described below. A scan of all or part of a patient's mandible with teeth, comprising at least one tooth stump, is performed. An original data set defining the geometry of said all or part of the mandible with teeth is thus obtained. For example, this data set is a file in STL (Standard Triangle Language) format. The data file can be in any other format other than the STL format, which can be read and interpreted by a 3D printer. A first processed data set defining the geometry of the model mandible 1 with teeth, including the toothless space 2, the cavity 3, and the through holes 10a, 10b, is created from this original data set. A second processed data set defining the geometry of the main body 5 of the model tooth stump 4, including the housing 7 and the through hole 11b, is also created. These two processed data sets are STL files, for example, which are created using a 3D shape editing program with which the original data STL file is edited, such that the mandible with teeth is cut down and separated into two parts: the model mandible 1 with teeth and the main body 5, and all the geometries needed for the couplings, i.e., the cavity 3, the first end 4a, the through holes 10a, 10b, and 11b, and the housing 7, are created in these two parts. In these processed data STL files, the assembly formed by the model mandible 1 with teeth and the main body 5 of the model tooth stump 4, when the first end 4a is introduced in the cavity 3, has a geometry corresponding to the geometry of the mandible with teeth defined in the original data STL file. The model mandible 1 with teeth and the main body 5 are manufactured from resin by means of 3D printing from these first and second processed data STL files, respectively. The rigid insert 6 is introduced in the housing 7 of the main body 5 and is integrally attached to said body by means of an adhesive. Finally, the screws constituting the second fixing means 9a, 9b are supplied.