Abstract
Disclosed is a method for manufacture of a removable dental prosthesis by moulding, the method including: digital modelling of a prosthesis model; a step of producing a mould including a lower half-shell corresponding to a tooth part of the prosthesis and an upper half-shell corresponding to a gum part of the prosthesis, the two half-shells being able to be joined together by affixing one to the other, thereby forming an impression of the prosthesis, the step including digital modelling of a model of the mould, followed by additive manufacture of at least the lower half-shell, and a step of producing the prosthesis, the step including in succession at least one provision of at least one artificial tooth, positioning of the artificial tooth in a seat of the lower half-shell, assembling the mould and pouring a filler material into the mould. Also disclosed is a prosthesis obtained by this method.
Claims
1. A method for manufacture of a removable dental partial prosthesis by moulding, said method comprising the following successive steps: a step of digitally modeling a prosthesis model, the prosthesis model representing the prosthesis to be produced and comprising a gum part and a tooth part; a step of producing a mould from the digitally modeled prosthesis model, said mould comprising upper and lower half-shells, the lower half-shell comprising a first imprint of the tooth part of the prosthesis, and the upper half-shell comprising a second imprint of the gum part of the prosthesis, the upper and lower half-shells being configured to be assembled by juxtaposition against each other, imprints of each half-shell forming by assembly an imprint of the prosthesis, the mould also comprising a positioning member for positioning one of the upper and lower half-shells relative to the other one of the upper and lower half-shells, the step of producing the mould including at least successive sub-steps of: partial digital modeling of a mould model according to the prosthesis model, followed by additive manufacture of at least the lower half-shell according to the mould model; and a step of producing the prosthesis, including at least successive sub-steps of: providing at least one artificial tooth, positioning the artificial tooth in an accommodation of the lower half-shell, assembling the mould, and casting a filling material in the mould, wherein the mould is a partial prosthesis mould, the gum part and the tooth part each being partial, wherein the positioning member comprises at least one support member configured to support a third imprint of existing teeth, the support member formed of one or more plates and abutments, said plates and abutments mounted on and extending from a support plate, said plates and abutments presenting top surfaces that fit against correspondent lower surfaces of the third imprint of the existing teeth when assembled with the upper half-shell, and wherein the positioning member is formed as a complementarity of both of the second imprint of the gum part of the upper half-shell and the third imprint of the existing teeth of the upper half-shell, and of both of the first imprint of the tooth part and the support member of the lower half-shell.
2. The method according to claim 1, wherein the sub-step of additive manufacture of the mould is carried out by photopolymerisation.
3. The method according to claim 2, wherein the sub-step of additive manufacture of the mould is carried out by a method comprising a succession of additions of material by jets on a printing substrate, layerwise, the polymer being solidified by photopolymerisation after each jet.
4. The method according to claim 2, wherein the additive manufacture material of said additive manufacture is selected from the group consisting of: acrylic monomers, epoxide monomers, and acrylonitrile butadiene styrene.
5. The method according to claim 1, wherein the sub-step of additive manufacture of the mould is carried out by a succession of additions of material by jets on a printing substrate, layerwise, the polymer being solidified by photopolymerisation after each jet.
6. The method according to claim 5, wherein the additive manufacture material of said additive manufacture is selected from the group consisting of: acrylic monomers, epoxide monomers, and acrylonitrile butadiene styrene.
7. The method according to claim 1, wherein additive manufacture material of said additive manufacture is selected from the group consisting of: acrylic monomers, epoxide monomers, and acrylonitrile butadiene styrene (ABS).
8. The method according to claim 1, wherein additive manufacture material of said additive manufacture is selected from the group consisting of: polylactic acid polymers (PLA), polyvinyl alcohol (PVA), acrylonitrile butadiene styrene (ABS), and ethylene terephthalate (PET).
9. The method according to claim 1, wherein the filling material is an acrylic monomer.
10. The method according to claim 1, wherein the positioning member is completed by cobalt-chrome metal (22) so as to provide sealing of the mould.
11. The method according to claim 1, wherein the step of producing the prosthesis is preceded by a step of taking an imprint.
12. The method according to claim 1, wherein the step of producing the prosthesis is followed by at least one step of removing the prosthesis from the mould and/or finishing.
13. The method according to claim 1, wherein the additive manufacture material of said additive manufacture is an acrylic monomer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The removable dental prosthesis manufacturing method according to the invention will be better understood in the light of the following detailed description, given by way of non-limiting indication, with reference to the accompanying drawings illustrating three embodiments: a first embodiment illustrated in FIGS. 1 to 11, a second embodiment illustrated in FIGS. 12 to 16, and a third embodiment illustrated in FIGS. 17 to 28. FIGS. 1 to 28 take the following form:
FIRST EMBODIMENT OF THE INVENTION
(2) FIG. 1 is a diagrammatic representation of a perspective view of a dental prosthesis model, according to a first embodiment of the invention;
(3) FIG. 2 is a diagrammatic representation of a perspective view of the model of FIG. 1 in which an artificial delimitation enables a separation into two parts (tooth part and gum part);
(4) FIG. 3 is a diagrammatic representation of a perspective view of the model of FIGS. 1 and 2 after the separation into two parts of the item of FIG. 2;
(5) FIG. 4 is a diagrammatic representation of the production of a model of a lower half-shell of the mould from the first of the two parts of FIG. 3, in perspective view from above (FIG. 4A) and from below (FIG. 4B);
(6) FIG. 5 is a diagrammatic representation of the production of a model of an upper half-shell of the mould from the second of the two parts of FIG. 3, in perspective view from above (FIG. 5A) and from below (FIG. 5B);
(7) FIG. 6 is a diagrammatic representation of a perspective view of the mould model produced by assembly of the two half-shell models by juxtaposition against each other, producing the imprint of the model;
(8) FIG. 7 is a diagrammatic representation of a perspective view of a half-shell corresponding to the tooth part produced by additive manufacture from the first half-shell model of FIG. 4, and also represents the sub-step of providing at least one tooth 20 as well as a sub-step of positioning at least part of that tooth 20;
(9) FIG. 8 diagrammatically represents a perspective view of the half-shell corresponding to the gum part produced by additive manufacture on the basis of the second half-shell model of FIG. 5;
(10) FIG. 9 is a diagrammatic view in perspective of the mould constituted by the half-shells of FIGS. 7 and 8, and also represents the sub-step of casting from the step of actual production of the dental prosthesis;
(11) FIG. 10 is a diagrammatic representation of a perspective view of the step of removal from the mould of the dental prosthesis produced by the method for manufacture in the casting sub-step illustrated by FIG. 9; and
(12) FIG. 11 is a diagrammatic representation of a perspective view of two complete dental prostheses, an upper jaw prosthesis obtained further to the step of FIG. 10, and a lower jaw prosthesis obtained similarly.
SECOND EMBODIMENT OF THE INVENTION
(13) FIG. 12 is a diagrammatic representation of an exploded perspective view of three parts forming a dental prosthesis mould obtained after modelling, according to a second embodiment of the invention;
(14) FIG. 13 is a diagrammatic representation in detail of one of the three parts (tooth part) of the dental prosthesis mould of FIG. 12;
(15) FIG. 14 is a diagrammatic representation of a perspective view of the dental prosthesis mould of FIGS. 12 and 13 after the fastening of one part of the three parts on another of the three parts;
(16) FIG. 15 is a diagrammatic representation of a perspective view of the mould after assembly;
(17) FIG. 16 is a diagrammatic representation of another perspective view, complementary to FIG. 15, of the mould after assembly,
THIRD EMBODIMENT OF THE INVENTION
(18) FIG. 17 is a diagrammatic representation of a perspective view of a first part (gum part) of a dental prosthesis mould model, according to a third embodiment of the invention;
(19) FIG. 18 is a diagrammatic representation of a perspective view of a second part (support bar) of the dental prosthesis mould model of FIG. 17;
(20) FIG. 19 is a diagrammatic representation of a perspective view of the first part and of the second part of the dental prosthesis mould model, the second part (support bar) being re-worked;
(21) FIG. 20 is a diagrammatic representation of a perspective view from above of a third part (tooth part) of the dental prosthesis mould model of FIGS. 17 to 19;
(22) FIG. 21 is a diagrammatic representation of a perspective view from below of the third part from FIG. 20, reworked;
(23) FIG. 22 is a diagrammatic representation of a perspective view from above (FIG. 22A) and from below (FIG. 22B) of a lower half-shell corresponding to the gum part produced by additive manufacture from the half-shell model of FIGS. 17 and 20;
(24) FIG. 23 is a diagrammatic representation of a perspective view from above (FIG. 23A) and from below (FIG. 23B) of an upper half-shell corresponding to the tooth part produced by additive manufacture from the half-shell model of FIGS. 18 and 20;
(25) FIG. 24 is a diagrammatic representation of a perspective view from above of the half-shell of FIG. 23 at the time of the sub-step of providing an artificial tooth 45 as well as at the time of the sub-step of positioning another artificial tooth 44.
(26) FIG. 25 is a diagrammatic representation of an exploded perspective view of the assembly of the mould formed from the half-shells of FIGS. 22 and 23 and of a support bar corresponding to the part of FIGS. 19 and 20;
(27) FIG. 26 is a diagrammatic representation of a cross-section view of the mould after assembly;
(28) FIG. 27 is a diagrammatic representation of a perspective view of the mould after assembly and before casting the resin;
(29) FIG. 28 is a diagrammatic representation of a perspective view of the removal from the mould of a prosthesis so obtained after casting the resin.
(30) In the Figures, identical parts are identified by identical numerical references.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(31) The first embodiment discloses all the steps of the method according to the invention, with the exception of the step of taking an imprint. The second embodiment is described only as regards the modelling, the manufacture and the assembly of the mould, the steps of casting filling material in the mould for actual manufacture of the dental prosthesis, then removal from the mould of the dental prosthesis so obtained, being transposable from the first embodiment. The third embodiment discloses all the steps of the method according to the invention, with the exception of the step of taking an imprint.
FIRST EMBODIMENT OF THE INVENTION
(32) FIGS. 1 to 10 according to the first embodiment of the invention illustrate the case of a method for manufacture of a complete dental prosthesis, here for an upper jaw. FIGS. 1 to 6 represent phases of computer aided design, which generates models, while FIGS. 7 to 10 represent phases of actual manufacture itself, comprising the actual production by additive manufacture of the mould then the actual production of the dental prosthesis using the mould. FIG. 11 illustrates the case of two complete dental prostheses, of the upper jaw and lower jaw, obtained by the method of the invention, the lower jaw dental prosthesis having been produced in the same way as the dental prosthesis manufactured in the steps illustrated by FIGS. 1 to 10.
(33) As FIG. 1 illustrates, a digital file representing a model 10 of a three-dimensional removable dental prosthesis was produced in STL format using a computer-aided design (CAD) software application, such as an application such as SolidWorks®, Sculpt® or Maya®. The three-dimensional imprint of the model 10 of FIG. 1 will next be processed by a general software application, such as Magics®, or by a specific software application, for example such as 3Shapes®, Exocad® or Dental Wings®, to reconstitute dentition therein as well as the gum profiles.
(34) This step of producing the three-dimensional dental prosthesis model was preceded by a step of taking an imprint (not illustrated) carried out either on a plaster model by virtue of a table scanner, or, preferably, directly by virtue of an intraoral scanner.
(35) The following phases, illustrated by FIGS. 2 to 6, illustrate the sub-step of three-dimensional modelling of the mould.
(36) FIG. 2 represents the model 10 of FIG. 1, in which a delimitation 11 has been made, thereby separating the model into two parts, an upper part 12 referred to as gum part and a lower part 13 referred to as tooth part.
(37) Any form of delimitation may be envisioned, provided the greater part, or possibly the entirety of the teeth, is present in the lower part. According to a preferred embodiment, the delimitation is carried out substantially in a plane (called parting plane) which facilitates manipulation while making it possible, subsequently, to produce two half-shells that can easily be joined to each other in that plane.
(38) FIG. 3 represents the model 10 of FIG. 1, after separation of the upper part; or gum part, 12, and of the lower part, or tooth part 13, according to the delimitation 11. A model 10′ is thus obtained as represented, separated into two parts which are a gum part 12′ and a tooth part 13′.
(39) FIG. 4 is a diagrammatic representation of production of a model of a first mould half-shell 130 corresponding to the tooth part 13′ of the model 10′. This first half-shell model 130 was produced as a negative of the part 13′ of FIG. 3, which thus comprises an accommodation for the teeth, in perspective view from above (FIG. 4A) and from below (FIG. 4B). The outside surface of the tooth part 13′ of the model 10′ of FIG. 3 corresponds in every respect to the inside surface of the half-shell 130. The periphery of this inside surface is completed by a U-shaped planar wall 150c. The first half-shell model, or offset, 130 is hollow and comprised within a U-shaped three-dimensional virtual volume, delimited by the wall 150c, in this adopting substantially the shape of an upper jaw.
(40) The thickness of this model, or skin, is approximately 0.5 mm. Advantageously, this thickness is produced through homethecy by excess thickness relative to the outside surface of the model 10′ of FIG. 3. This thickness is uniform by virtue of the use of additive manufacture, which makes it possible to save material. The additive manufacture is particularly advantageous from this point of view.
(41) The depth P.sub.5 of the U is here of greater or equal magnitude to the height of the teeth. It extends between two substantially parallel planes, one of which corresponds to the delimitation 11 and is materialized by the planar wall 150c, the other plane (virtual) being substantially parallel to the plane 150c. A lateral wall 150d links these two planes over the periphery of the U. The first half-shell 130 comprises two centring holes 150a and 150b which are located in the rear part, that is to say on the two ends of the U. The centring holes 150a and 150b extend recessed from the wall 150c towards the inside of the first half-shell model 130. Preferably, they are of length less than or equal to the depth of the U, P.sub.5.
(42) FIG. 5 is a diagrammatic representation of production of a model of a second mould half-shell 140 corresponding to the gum part 12′ of the model 10′. This second half-shell model 140 was produced as a negative of the part 12′ of FIG. 3, which thus constitutes an imprint of the gum part, in perspective view from above (FIG. 5A) and from below (FIG. 5B). The outside surface of the gum part 12′ of the model 10′ of FIG. 3 corresponds in every respect to the inside surface of the half-shell 140. The periphery of this lower surface is completed by a U-shaped planar wall 160c, configured to cooperate with the planar wall 150c of the half-shell 130. At the periphery of the planar wall 160c there is a slight rim 160d in the form of a rib, configured to stiffen the half-shell 140. The second half-shell model 140, or offset, is hollow and is included within a U-shaped three-dimensional virtual volume, delimited by plane 160.
(43) The depth P.sub.6 of the U is here of greater or equal magnitude to the height of the gum. It extends between two substantially parallel planes. One of these planes corresponds to the plane of the delimitation 11 and is materialized by the wall 160c, the other plane (virtual) being substantially parallel to that first plane 160c. The second half-shell 140 comprises two centring pins 160a and 160b which are located in the rear part, that is to say on the two ends of the U. The pins 160a and 160b extend projecting from the wall 160c towards the outside of the second half-shell model 140 and are of length substantially identical to that of the respective centring holes 150a and 150b, with which they are respectively configured to cooperate.
(44) FIG. 6 is a diagrammatic representation of a perspective view of the mould model 8 produced by assembly of the two first and second half-shells models 130 and 140 by juxtaposition against each other by virtue of the (virtual) insertion of the centring pins 160a and 160b into the respective holes 150a and 150b. The mould model 8 thus form the imprint (or the negative) of the offset 10′. The mould so virtually formed defines the shape of the upper jaw to produce as a complete dental prosthesis. The production of this mould model 8 marks the end of the CAD phase of the method.
(45) The vents and casting hole(s) are not shown in FIGS. 4 to 6 in the interest of simplification but are preferably also modelled.
(46) FIG. 7 is a diagrammatic representation of a perspective view of a first half-shell 3 corresponding to the tooth part produced by additive manufacture, for example by SLA, from the first half-shell model 130 of FIG. 4.
(47) FIG. 8 is a diagrammatic representation of a perspective view of a second half-shell 4 corresponding to the tooth part produced by additive manufacture, for example by SLA, from the second half-shell model 140 of FIG. 5.
(48) FIG. 9 is a diagrammatic view in perspective of the mould 5 constituted by the assembly of the first half-shell 3 of FIG. 7 and the second half-shell 4 of FIG. 8, producing the imprint of the model 10′.
(49) The half-shell 3 comprises centring holes 15a and 15b, a U-shaped planar wall 15c from which project the U-shaped lateral wall 15d. In this it reproduces the aspects of the virtual half-shell 130 and of its parts 150a, 150b, 150c and 150d. The half-shell 4 comprises two centring pins 16a and 16b, a planar wall 16c and a rim 16d. In this it reproduces the aspects of the virtual half-shell 140 and of its parts 160a, 160b, 160c and 160d.
(50) The positioning member of this first embodiment is thus formed by at least two pins (16a, 16b) present on a planar part of the wall or on a planar wall 16c, preferably on a planar wall 16c, of one of the two half-shells 4 configured to cooperate respectively with at least two centring holes (15a, 15b) present on a planar wall part or on a planar wall 15c, preferably on a planar wall 15c, of the other of the half-shells 3. In the case represented here, the two walls (15c, 16c) are (entirely) planar and are configured to be juxtaposed against each other over their whole surface.
(51) In a preferred embodiment, represented here, the two walls 15c and 16c are U-shaped. However, they may also have another geometrical shape, provided those shapes cooperate with each other to provide positioning engagement. In a preferred embodiment, independently or not independently of the preceding embodiment, the outside periphery of the wall 16c and the inside periphery of the wall 15d substantially coincide at the time of their positioning engagement.
(52) The vents are not represented in FIGS. 7 and 8 in the interest of simplification. However, they are represented in FIG. 9.
(53) In FIG. 7 artificial teeth 20 are moreover represented, illustrating at the same time a sub-step of providing teeth 20 as well as a sub-step of positioning those teeth 20 in an accommodation corresponding to the first half-shell 3.
(54) The first half-shell 3 comprises holes 15a and 15b respectively for centring pins 16a and 16b of the second half-shell 4.
(55) In FIG. 8, it can be seen that the second half-shell 4 comprises a supply channel 17, also designated “runner” configured to enable the flow of a filling material (which is in liquid form or in powder form) into the imprint formed by the two assembled half-shells 3, 4. The supply channel 17 is represented here as central (relative to the U-shape of the model), preferably emerging onto a part of the imprint that is as untechnical as possible. It comprises a supply hollow 17a and a flow channel 17b opening both into the imprint of the half-shell 4 and into the supply hollow 17a. The filling material is introduced by the supply hollow 17a on casting.
(56) However, any other location of the supply channel 17 may be envisaged in the context of the invention, according to a variant not shown.
(57) In FIG. 9, the half-shells 3 and 4 have been juxtaposed against each other by assembly and insertion of the centring pins 16a and 16b in the centring holes 15a and 15b, the planar surfaces 15c and 16c being pressed against each other after positioning of the set of teeth 20 in the accommodations of the imprint of the first half-shell 3. The presence of two vents 18a and 18b can be seen, which are formed here vertically in the upper part of the second half-shell 4.
(58) FIG. 9 illustrates a casting sub-step. Thus, a filling material is poured into the supply channel 17, as shown by arrow F. During this casting sub-step, the air present in the mould 5 is flushed via the two vents 18a and 18b, as shown by the respective arrows Fa and Fb.
(59) Therefore, an upper jaw dental prosthesis 9 has been produced by moulding inside the mould 5.
(60) FIG. 10 is a diagrammatic representation of a perspective view of the removal from the mould of the prosthesis 9. The dental prosthesis 9 comprises, by definition, a gum part 90 and a tooth part 91, itself comprising the teeth 20. The removal from the mould carried out here is total by application of two forces effecting two opposite withdrawal movements, illustrated by the arrows f.sub.1 and f.sub.2
(61) The prosthesis 9, once extracted free from the mould, advantageously undergoes smoothing by abrasive (at the locations at which the supply channel and the vents emerged), and possibly any finishing step known in the art.
(62) FIG. 11 is a diagrammatic representation of a perspective view of two complete dental prostheses 9 and 7, the upper jaw prosthesis 9 being obtained further to the step of FIG. 10, and the lower jaw prosthesis 7 being obtained similarly. These two complete dental prostheses 9 and 7 may be fastened to the jaw, temporarily, by adhesive suction, or by use of a fastening past or cream promoting that phenomenon of adhesive suction.
SECOND EMBODIMENT OF THE INVENTION
(63) FIGS. 12 to 16 according to the second embodiment of the invention illustrate the case of a method for manufacture of a partial dental prosthesis, with stellite 22, here for an upper jaw. FIGS. 12 to 16 all represent the mould 29 once designed and manufactured by additive manufacture, before moulding (FIGS. 12 to 14) and after manufactured (FIGS. 15 and 16).
(64) Thus, FIG. 12 is a diagrammatic representation of an exploded perspective view of the parts forming the dental prosthesis mould 29, which are an upper half-shell 21 (gum part), a lower half-shell 23 (tooth part) obtaining after modelling, as well as a stellite 22. The lower half-shell 23 is represented in FIG. 13 in a slightly different perspective view, which enables its form to be better perceived. The stellite 22 has been designed, as known to the person skilled in the art, based on the step of taking an imprint.
(65) The step of taking an imprint was carried out by direct scanning in the mouth by intra-oral scanners, or by direct scanning on the imprint-taking made, for example, with alginate, the plaster model arising therefrom, or for instance by scanning. It is then possible to model the virtual model (in CAD) of the stellite, of the gum part and of the tooth part, for example using the Dental Wings® software.
(66) The mould 29 is formed from these three parts 21, 22 and 23.
(67) The lower half-shell 23 corresponds to the tooth part of the prosthesis to form and comprises the imprint of the tooth part to form (here two imprints 23a and 23c) supported by at least one support member 23b, here constituted by different support plates and different support abutments, said support member 23b preferably being borne, as is the case here, by a support plate 23d.
(68) The stellite 22 is formed from a single piece of metal, which comprises two linking parts 22b and 22c, respectively corresponding to the members 23c and 23a of the tooth part, as well as a part 22a configured to be incorporated behind the teeth still present and a part 22d configured to bear on the palate. The stellite 22 is a piece of the mould, but also a piece of the partial dental prosthesis once this has been produced.
(69) The upper half-shell 21 comprises the gum part of the dental prosthesis, and comprises the imprint of the gum part to produce, here in two parts 21a and 21c around the imprint of the teeth still present 21b, and an upper support part 21d. If necessary, the artificial teeth which will be incorporated into the final prosthesis are machined, in particular to enable better fastening, via for example an aperture enabling partial passage of the stellite. The stellite is of cobalt-chrome metal, as is known in the art.
(70) The upper half-shell 21, which corresponds to the dental imprint of the patient's upper jaw, may be producing in a plaster mould, and in that case be solid. However, it is preferably produced by additive manufacture.
(71) The lower half-shell 23 is manufactured by additive manufacture. The members 23c and 23a are configured to form the actual partial prosthesis, in combination with the corresponding gum part 21c and 21a of the upper half-shell 21, while incorporating the parts 22b and 22c of the stellite 22.
(72) The positioning member thus comprises at least one support member 23b configured to support the imprint of the existing teeth 21b. Produced in this way, the positioning member basically consists of the complementarity of the imprint of the gum part (21a, 21c) and of the existing teeth 21b of the upper half-shell 21 and of the imprint of the tooth part (23a, 23c) and of the support member 23b of the lower half-shell 23. The positioning member is preferably, as is the case here, completed by the stellite 22 so as to provide sealing of the mould. This is particularly advantageous when casting the filling compound.
(73) FIG. 14 is a diagrammatic representation of a perspective view of the dental prosthesis mould of FIGS. 12 and 13, after the fastening of the stellite 22 on the lower half-shell 23, at the locations provided for that purpose of the members 23a, 23c, and of the abutments 23b.
(74) The abutments 23b comprise locations for receiving the stellite 22. They are members here represented as solid members, mainly to simplify the representation. However, it is preferred in the context of the invention to provide hollow abutments so as to save additive manufacture material, which is the filling material.
(75) FIGS. 15 and 16 diagrammatically represent two complementary perspective views of the mould after assembly.
(76) Therein it is possible to see the assembled mould 29, consisting of the upper half-shell 21, the stellite 22 and the lower half-shell 23. The supply of the filling material is made by runners (not shown) in the mould level with the members 23a and 23c of the lower half-shell, the mould 29 possibly further comprising at least one vent (not shown). This mould advantageously makes it possible to produce a prosthesis according to the invention, as was explained previously for the first embodiment.
THIRD EMBODIMENT OF THE INVENTION
(77) FIGS. 17 to 28 according to the third embodiment of the invention illustrate the case of a method for manufacture of a complete dental prosthesis, here for the upper jaw, comprising a support bar 49 configured to fasten the prosthesis in the mouth by cooperation with six implants present in the jaw. FIGS. 17 to 23 represent phases of computer aided design, which generates models, while FIGS. 24 to 28 represent phases of actual manufacture itself, comprising the actual production by additive manufacture of the mould then the actual production of the dental prosthesis using the mould.
(78) The support bar 49 is produced by additive manufacture. It could also have been produced by lost wax casting.
(79) FIG. 17 is a diagrammatic representation of a perspective view of a first part 37 (gum part) of a dental prosthesis model, produced on the basis of the step of taking an imprint. The upper part 37 comprises a part corresponding to the gum 37a, a part corresponding to the palate 37b, as well as a peripheral part 37c.
(80) FIG. 18 is a diagrammatic representation of a perspective view of a second part (support bar 36) of the dental prosthesis mould model of FIG. 17. The support bar 36 comprises a semi-circular main part 36a, and six different holding abutments 36b, the central part 36a bearing on these abutments 36b, configured to be placed in relation subsequently with the six implants of the patient. It is hollow and corresponds to the support bar 49 as it will be finally produced.
(81) FIG. 19 is a diagrammatic representation of a perspective view of the first part and of the second part of the dental prosthesis mould model, reworked by CAD. Thus, the support bar 36 has been reworked as a support bar 43, which is a solid model (as opposed to the hollow model of FIG. 18), so as to be able to rework the part 37 (gum part) as part 48. The support bar 43 comprises a semi-circular main part 43a, and six different holding abutments 43b, the central part 43a bearing on these abutments 43b, configured to be placed in relation subsequently with the six implants of the patient. Part 48 comprises an actual gum part 48a, in which have been created six hollow parts or accommodation platforms 48b configured to enable the positioning of part 43, and corresponding to the cavities of the six abutments 43b at their bases configured to face part 48. Part 48 must be reworked further to comprise a hollow part corresponding to a support bar main part. This enables the later positioning of the support bar relative to the gum part, in the mould and then also in the prosthesis.
(82) FIG. 20 is a diagrammatic representation of a perspective view from above of a third part 38 (tooth part) of the dental prosthesis mould model of FIGS. 17 to 19. Part 38 is solid. It comprises a tooth part 38c and a gum part 38b.
(83) FIG. 21 is a diagrammatic representation of a perspective view from below of the third part 38 from FIG. 20, reworked. As explained earlier, the support bar 43 is a solid model (as opposed to the hollow model of FIG. 18), so as to be able to rework part 38 (tooth part). Part 38 comprises a hollow part 38a corresponding to an accommodation of the lower part of the main part 43a of the support bar 43, and six hollow parts 38d or accommodation platforms corresponding to the six abutments 43b. This enables the latter positioning of the support bar relative to the tooth part in the mould.
(84) FIG. 22 is a diagrammatic representation of a perspective view from above (FIG. 22A) and from below (FIG. 22B) of a mould hollow upper half-shell 41 corresponding to the gum part 48, produced by additive manufacture from the model of the part of FIG. 19. The outside surface of the gum part 48 of FIG. 19 corresponds in every respect to the inside surface of the half-shell 41.
(85) The thickness of the upper half-shell 41 is practically uniform and enables a particularly advantageous saving of material.
(86) It is possible to distinguish an actual gum part 41a, a palate part 41b, a rim part 41c, a part 41d corresponding to an accommodation platform of the upper part of the main part 49a of the support bar 49, and a part 41e corresponding to an accommodation platform of the upper part of the abutments 49b of the support bar 49.
(87) FIG. 23 is a diagrammatic representation of a perspective view from above (FIG. 23A) and from below (FIG. 23B) of a mould hollow lower half-shell 42 corresponding to the tooth part 38c produced by additive manufacture from the half-shell model of FIGS. 20 and 21. The outside surface of the tooth part 38c of FIG. 20 corresponds in every respect to the inside surface of the half-shell 42.
(88) The thickness of the lower half-shell 42 is practically uniform and enables a particularly advantageous saving of material.
(89) It is possible to distinguish a gum part 42e, a tooth part 42c, a rim part 42d, a substantially planar upper part 42a and a circular peripheral lateral part 42b. Parts 42a and 42b advantageously make it possible to rigidify the bottom part of the mould once this has been produced by additive manufacture.
(90) FIG. 24 is a diagrammatic representation of a perspective view from above of the lower half-shell of FIG. 23 at the time of the sub-step of providing an artificial tooth 45 as well as at the time of the sub-step of positioning another artificial tooth 44. In this Figure, it can be seen that the artificial tooth 45 has already been positioned, while the artificial tooth 44 is in course of being positioned. The artificial teeth 44 and 45 each comprise passage apertures for screws which have been machined in them in advance. This apertures enable the fastening, before filling, of the abutments of the support bar 49 in the artificial teeth. This manner of proceeding is carried out as many times as necessary to provide all the six artificial teeth.
(91) FIG. 25 is a diagrammatic representation of an exploded perspective view of the assembly of the mould formed from the upper 41 and lower 42 half-shells of FIGS. 22 and 23 and of a support bar (stellite) 49 corresponding to the modelled support bar (36, 43) of FIGS. 19 and 20; All the artificial teeth have been placed in advance in the lower half-shell 42. As explained above, the support bar 49 is fastened, level with each of the abutments 49b in the apertures of the artificial teeth 44, 45 . . . , then the upper half-shell 41 obturates the assembly. The support bar 49 will later be fastened by retention due to the resin inside the prosthesis 45.
(92) The support bar 49 is configured to be interposed between the two half-shells (41, 42) on assembly, the support bar 49 comprising at least two holding abutments 49b and a semi-circular main part 49a bearing on these abutments, the support bar 49 being configured to be positioned on the lower half-shell 42 by at least one fastening means of at least one abutment 49b on at least one artificial tooth 44 housed in the tooth part of said lower half-shell 42, and the support bar 49 being configured to be positioned on the upper half-shell 41 by at least one accommodation platform of the upper part of the abutments.
(93) Thus, the positioning member is formed by the complementarity of the imprint of the tooth part of the lower half-shell 42 and of the imprint of the gum part of the upper half-shell 41. Preferably, the positioning member consists of the complementarity of the imprint of the tooth part of the lower half-shell 42 and of the imprint of the gum part of the upper half-shell 41.
(94) FIG. 26 is a diagrammatic representation a cross-section view of the mould after having juxtaposed the two half-shell 41 and 42 against each other by assembly. It is possible to distinguish the upper half-shell 41, the lower half-shell 42, the support bar 49 and an artificial tooth 44. It can be seen that the support bar 49 is screwed to the artificial tooth 44 level with one of its abutments.
(95) FIG. 27 is a diagrammatic representation of a perspective view of the mould after assembly, and before casting the assembly material. It is possible to see therein the injection symbolized by a syringe partly filled with filling material, as well as a runner 41f for the supply of filling material. A single runner 41f has been symbolized. According to the invention, several runners may be present. The hole or holes 41f may have been machined in the lower half-shell 42 just prior to the assembly of the mould, as is symbolically represented here, or have been provided in the half-shell of the mould as of it being modelled. According to a preferred variant, the runner is complemented by at least one vent.
(96) FIG. 28 is a diagrammatic representation of a perspective view of the removal from the mould of a prosthesis 51 so obtained after casting the filling material in the mould (41, 49, 42). The removal from the mould is carried out by application of two forces executing two opposite withdrawal movements, illustrated by the arrows Fh and Fb. The prosthesis 51 is composed of a resin 46 solidified around artificial teeth and the support bar 49. The abutments of the support bar will enable the positioning of the prosthesis 51 in the jaw of the patient via implants. These implants will thus be joined to the prosthesis 51.
