METHOD FOR MANUFACTURING A DENTAL PROSTHESIS AND SHELL MOLD FOR CARRYING OUT THE METHOD

Description

[0001] The present invention relates to a method for manufacturing a dental prosthesis, for example a removable, complete or partial dental prosthesis (more commonly called "stellite").

[0002] It also relates to a shell mold configured to implement such a process.

[0003] A dental prosthesis here refers to a device that replaces at least some of the natural teeth.

[0004] A removable dental prosthesis is a prosthesis that can be removed from the mouth, for example for daily maintenance or for sleeping.

[0005] A "complete" dental prosthesis, also called dentures, refers to a prosthesis that replaces all the teeth, whether in the upper jaw for an upper denture or in the lower jaw for a lower denture.

[0006] A "partial" dental prosthesis is used when it is only a matter of replacing one tooth, or some of the teeth, but not the whole thing.

[0007] A partial denture traditionally consists of a metal framework, or stellite, which supports artificial teeth positioned in the space of the missing teeth. This rigid metal framework (usually made of chromium-cobalt-molybdenum) rests on both the remaining teeth and the mucous membranes, primarily the gums.

[0008] A dental prosthesis can also be held in place in the mouth by at least one implant. An implant is a metallic element, possibly fixed with a screw, in the bone, in order to replace the tooth root.

[0009] The fabrication of dental prostheses requires the implementation of a protocol comprising a series of highly precise steps, including a step called the molding process. This step consists of taking an impression of a prosthesis model made of wax, in a two-part separable mold called a mold. The model is made manually by a dental technician and includes artificial teeth arranged one after the other on the model.

[0010] In some cases, the impression is taken by pouring plaster into the mold. Once the plaster has hardened, the mold is scalded, and the melting wax is removed, leaving an impression in the plaster. The plaster mold must then cool before pouring a material, usually a resin, into the impression, in which artificial teeth have been previously placed.

[0011] In other cases, the impression is taken by pouring a gel into the flask. Once the gel has solidified, the wax model can be removed manually without scalding. However, the artificial teeth must be separated from the wax model before being positioned in the gel impression. Furthermore, the artificial teeth are usually scalded to remove any wax residue.

[0012] This flask preparation stage, including sub-stages of plaster solidification, scalding of the flask, cooling, or separation of the artificial teeth from the wax model, is time-consuming and considerably delays the actual creation of the prosthesis.

[0013] The US2020146791A1 document describes a method for manufacturing a dental prosthesis, including a digital design stage of a dental prosthesis model to be made from a replica model of a patient's dentition; a 3D printing manufacturing stage of the jaw part; a stage of making an impression of the base of the prosthesis; a stage of pouring a filling material into a residual volume defined by the impression of the base; a stage of positioning artificial tooth models (in wax) in the base, for a "lost wax" overmolding of the final teeth in the base.

[0014] The present invention therefore aims to remedy, at least in part, these drawbacks.

[0015] Its aim is in particular to offer a process that saves time and makes manufacturing a dental prosthesis easier.

[0016] To this end, the invention relates, according to a first aspect, to a method for manufacturing a dental prosthesis comprising: a digital design step of a dental prosthesis model to be made from a replica model of a patient's dentition; a generation step of a jaw part model including the replica dentition model and the dental prosthesis model assembled to the replica dentition model; a digital design step of a positioning organ model in the replica dentition model; a manufacturing step of the jaw part including a positioning organ from the jaw part model including a positioning organ model; a manufacturing step of the replica dentition including a positioning organ from the replica dentition model including the positioning organ model;a step of positioning the jaw part on a shell of a shell mold by cooperation of the jaw part positioning organ with a complementary positioning organ provided in said shell; a step of closing the shell mold; a step of making an impression of the jaw part by injecting a material into the shell mold; a step of positioning at least one artificial tooth in the impression of the jaw part; a step of positioning the replica of the dentition on the shell of the shell mold by cooperation of the replica of the dentition positioning organ with the complementary positioning organ of the shell;a step of positioning the denture replica in the impression in which at least one artificial tooth is positioned, the denture replica only partially filling the impression, so as to form a residual volume in the impression; and a step of pouring a filling material into the residual volume formed in the impression, the at least one artificial tooth and the denture replica.

[0017] Such a dental prosthesis manufacturing process according to the invention thus allows a possible saving of time by avoiding steps such as boiling and cooling the muffle.

[0018] Indeed, the wax prosthesis model is here replaced by a part of the jaw made from a digitally designed model.

[0019] In practice, the jaw part is manufactured as a single piece.

[0020] As a result, no artificial teeth need to be removed or boiled since the jaw part is a single piece and is not necessarily reused in the rest of the process, which allows the artificial teeth to be positioned directly after the impression is taken and avoids the usual steps of boiling or retrieving artificial teeth.

[0021] Furthermore, a component material from the jawbone can then be recycled to enable the manufacture of other dental prostheses or other products. The same applies to the component material for the replica denture, which can be manufactured in the same way as the jawbone.

[0022] In one implementation example, the jaw part manufacturing step and the denture replica manufacturing step are carried out simultaneously.

[0023] Thus, the time required to produce the prosthesis can be shortened.

[0024] A process according to the invention thus makes it possible to easily and quickly obtain a dental prosthesis made on a case-by-case basis, that is to say, custom-made.

[0025] In addition, using a replica of a patient's dentition for the manufacture of the prosthesis, and more specifically during the pouring stage of a filling material, makes it possible to obtain a more precise fit between the prosthesis and the environment in which it is intended to be inserted than usual methods.

[0026] The presence of a positioning device on the denture replica, and therefore on the jaw component, allows for more precise positioning of these two elements on the shell of the mold using the complementary positioning device. This, in turn, allows for more precise positioning of the denture replica within the impression of the jaw component.

[0027] The positioning organ also serves, particularly when used in conjunction with a complementary positioning organ, to hold the jaw section or dentition replica in place on the shell of the shelled mussel. Such a positioning organ is, for example, formed on the lower part of the dentition replica.

[0028] In a privileged example, the positioning organ cooperates via a sliding connection with the complementary positioning organ provided on the shell.

[0029] For example, the cooperation between the positioning element and the complementary positioning element can form a dovetail joint.

[0030] In this way, the movement of the jaw part or the replica teeth relative to the shell is limited to translation along a single axis defined by the sliding joint. It is then possible to adjust the translational position along the axis defined by the sliding joint of at least one of the jaw parts or the replica teeth.

[0031] According to another privileged example, the positioning member has a groove configured to cooperate with the complementary positioning member.

[0032] According to another privileged example, the complementary positioning element includes a tab configured to cooperate with the positioning element.

[0033] The groove can have a polygonal cross-section and be configured to form a female part of a dovetail joint by cooperation with the complementary positioning member.

[0034] Similarly, the tongue can have a cross-section configured to form a male part of the dovetail joint through cooperation with the positioning element. The tongue may, for example, have a polygonal cross-section.

[0035] According to an interesting option, the additional positioning device also includes an axial stop.

[0036] For example, this axial stop can prevent the jaw component or denture replica from moving in translation when the positioning element cooperates with the complementary positioning element via the sliding joint. Thus, the axial stop provides a positioning reference point for the jaw component and / or denture replica relative to the shell. Indeed, it is possible to immobilize the jaw component and / or denture replica in a predetermined position by sliding it along the axis defined by the sliding joint until it reaches the axial stop.

[0037] Thus, the positioning of the jaw section on the shell is easily and quickly achieved by a prosthetist or any other practitioner, by sliding the jaw section until it reaches the stop. Furthermore, it is possible to position the replica teeth identically on the shell using the same method.

[0038] In one example implementation, the manufacturing step of the denture replica is preceded by a parallelization step of the denture replica model, in which undercut areas of the denture replica model are filled digitally.

[0039] These undercut areas are typically located at the junction between the teeth and the gums.

[0040] In the prior art processes, it was necessary to manually fill these undercut areas with wax.

[0041] Therefore, the realization step is configured to minimize, or even eliminate, the undercut areas of the denture replica model.

[0042] Thus, this step, carried out digitally, subsequently allows the fabrication of the denture replica in which the so-called parallelized areas are formed in one piece with the denture replica.

[0043] This is particularly advantageous during the impression-making stage in order to remove the jaw part from the mold without damaging the impression.

[0044] Furthermore, the undercut areas can be filled along a digitally determined insertion axis. The insertion axis corresponds to the direction in which the prosthesis will be inserted into the patient's mouth. The insertion axis is generally determined by the practitioner or by software.

[0045] According to one particular implementation example, the step of positioning the impression on the replica of the denture is preceded by a step of positioning a stellite framework on the replica of the denture.

[0046] A stellite frame is particularly useful in the case of a partial prosthesis, typically to hold together two separate parts of the prosthesis.

[0047] Advantageously, the stellite framework is attached to the dental prosthesis after the filling material has been poured.

[0048] The installation of the stellite frame is then easy and quick for a practitioner and guarantees optimal adaptation to the environment in which it is intended to be positioned.

[0049] According to another implementation example, the process further includes a step of drilling a feed channel opening into the cavity.

[0050] This feed channel is then used to pour the filling material to create the dental prosthesis. In one interesting example, at least two channels are drilled to allow both the pouring of the filling material and the evacuation of air present in the impression.

[0051] According to one implementation example, the manufacturing step of the jaw part and / or the replica of the teeth is carried out by additive manufacturing.

[0052] According to the invention, "additive manufacturing" refers to a manufacturing process involving the addition of material, most often computer-aided, more commonly known as "3D printing". Additive manufacturing techniques allow, for example, more precise manufacturing of the jaw component.

[0053] Thus, it is possible to refrain from manually making a wax model.

[0054] Furthermore, due to the precision of additive manufacturing, it may be possible to eliminate a polishing step which is often time-consuming and costly and likely to damage the part.

[0055] Thus, at least in some cases, a dental prosthesis to be made can come out directly ready for use from such a process, or with only a minimum of post-treatment steps, for example to obtain a mirror-polished appearance on certain surfaces of the dental prosthesis.

[0056] According to one example of implementation, the manufacturing step of the jaw part and / or the replica of the teeth is carried out according to a process comprising a succession of additions of material by jets onto an printing support, in successive layers, the material being solidified by photopolymerization after each jet.

[0057] For example, the jaw part can be made from a monomer, a polymer, or a light-cured resin. Preferably, the jaw part is made from PA 12 (for polyamide 12, also known as Nylon 12).

[0058] Indeed, PA 12 has interesting recycling capabilities for unmelted powder after the implementation of the additive manufacturing process as described here, and thus allows this powder to be reused to make other prostheses or even other products.

[0059] Also proposed, according to another aspect, is a shell mold for manufacturing a dental prosthesis, in which a shell has a bottom defining a flat surface and a complementary positioning member disposed on the bottom and configured to cooperate with a positioning member of an insert to be positioned on the bottom of the shell mold, characterized in that said complementary positioning member is configured to form a dovetail joint with said positioning member preventing movement of the insert in an out-of-plane direction, and in that the complementary positioning member has an axial stop.

[0060] Such a mold is thus specifically configured to implement a process as described above.

[0061] In the context of the invention, a "shell mold" means a mold formed by at least two cooperating parts, each part then being called a "shell".

[0062] An insert, as defined here, refers to any component that enables the implementation of at least some of the steps involved in taking an impression, molding, or overmolding for the purpose of creating a dental prosthesis. For example, according to the invention, the insert could be a replica of a patient's dentition or a portion of a jawbone.

[0063] Such a shell mold thus presents advantages similar to those described above in connection with the process.

[0064] The complementary positioning member is configured to form a sliding link with the positioning member of the insert.

[0065] In particular, the complementary positioning element is, for example, configured to form a male part of the dovetail assembly.

[0066] According to one embodiment, the complementary positioning member includes a tab configured to cooperate with the positioning member.

[0067] In particular, the axial stop can be formed by a protruding surface, extending transversely to the longitudinal direction of the tongue serving as a translational guide, for example perpendicularly on either side of the tongue, so that the complementary positioning member has a T-shape.

[0068] The invention, according to an exemplary embodiment, will be better understood and its advantages will become clearer upon reading the following detailed description, given by way of example and in no way limiting, with reference to the attached drawings in which: There figure 1 shows an example of a replica model of a patient's dentition according to one embodiment of the invention; The figure 2A shows a front, top-down view of a patient's sample denture replica model from the figure 1 , with a positioning device; The figure 2B shows a rear view, roughly from a low angle, of the replica denture model of the figure 2A ; There figure 3A shows an example of a jaw part model, in a plunging position, as obtained from the dentition replica example of the figures 2A et 2B , according to an implementation method of the invention; The figure 3B shows a rear view, roughly from a low angle, of the sample model of the jaw part of the figure 3A ; There figure 4 shows the positioning of a jaw part, created from the jaw part model of the figures 3A et 3B , on a shell of a shell mold, according to an example of an implementation of the invention; The figure 5 illustrates, through a perspective view, a stage of closing the shell mold with the jaw part positioned on one of the shells, as illustrated figure 4 ; There figure 6 shows an impression of the jaw section made in the shell mold and a step in the formation of a feeding channel; The figure 7 shows a step in positioning an artificial tooth in the impression of the figure 6 ; There figure 8 shows a step in the positioning of a replica denture, made from the replica denture model of the figures 2A et 2B , on the shell of the mussel in shells of the figure 4 ; There figure 9 illustrated by a perspective view, a stage of closing the shell mold with the replica dentition positioned on one of the shells as illustrated in the figure 8 ; There figure 10 shows a step of pouring a filling material inside the closed shell mold, including the replica of the dentures as shown in the figures 8 And 9 ; There figure 11 shows a dental prosthesis obtained according to an example of an implementation of the invention; and The figure 12 schematically presents a method for manufacturing a dental prosthesis according to an example of implementation of the invention.

[0069] Identical elements represented in the aforementioned figures are identified by identical numerical references.

[0070] There figure 1 represents a replica model of a patient's dentition 1.

[0071] Such a model is obtained for example from a digital impression step (not illustrated) carried out on a plaster model using a table scanner or, preferably, directly using an intraoral scanner in the patient's mouth.

[0072] The denture replica model 1 thus corresponds to a digital representation of a part of a patient's jaw, in this case a part of the lower jaw, for which a dental prosthesis must be made.

[0073] This denture replica model 1 is usually stored in an STL file and displayed from computer-aided design software.

[0074] The dentition replica model 1, for example, includes an upper part, mainly forming a teeth section, and a lower part, mainly forming a gum section.

[0075] The dentition replica model 1 also includes an anterior part, or lingual part, representing a concave inner face.

[0076] In the illustrated example, the dentition replica model 1 includes, in the upper part, at least one edentulous space 3.

[0077] Furthermore, in the illustrated example, the denture replica model 1 includes at least one remaining tooth 5. The dental prosthesis to be made is in this case a partial dental prosthesis.

[0078] Of course, the present invention is not limited to this type of dental prosthesis and also applies to other types of prostheses, for example, to a complete dental prosthesis, that is to say, one for which the replica denture model would not include any teeth 5.

[0079] As illustrated in figures 2A et 2B The dentition replica model 1 also includes a frontal part, representing a convex external face. The frontal part is thus opposite the anterior part, and the distance separating them constitutes the thickness of the dentition replica model 1.

[0080] The dentition replica model 1 also includes, in its lower part, a lower surface 7.

[0081] This surface, once the denture replica model 1 has been manufactured, is configured to position it stably on a support.

[0082] The lower surface 7 of the lower part of the dentition replica model 1 defines, for example, a plane.

[0083] THE figures 2A et 2B They also show a model of a positioning organ 8, formed in the model of the replica dentition 1, at its lower part. In particular, the model of the positioning organ 8 is formed from the lower surface 7 of the model of the replica dentition 1.

[0084] In the example shown, the positioning element model 8 has a groove 8a. The groove 8a is configured to form a sliding connection with a complementary element.

[0085] Indeed, groove 8a extends along a longitudinal axis between the anterior and frontal parts of the dentition replica model 1. Groove 8a here has a trapezoidal section which, by cooperation with a complementary organ, only allows movement along a longitudinal axis of groove 8a.

[0086] In the example shown in figures 2A et 2B The groove 8a is cut from the lower surface 7 of the denture replica model 1. The groove 8a extends parallel to the plane defined by the lower surface 7, over at least part of the thickness of the denture replica model 1. At the figure 2B For example, groove 8a extends from the anterior portion to the frontal portion of the denture replica model 1, that is, across the entire thickness of the denture replica model 1. In other words, groove 8a is a through groove. In this embodiment, the positioning element model 8 also includes a stop element or stop 8b configured to prevent the translational movement of the denture replica model 1. In one interesting option, the stop is formed by the frontal portion of the denture replica model 1. In this embodiment, the stop 8b has a protrusion extending from the frontal portion of the denture replica model 1. The protrusion of the stop 8b has a flat surface perpendicular to the longitudinal axis of groove 8a.

[0087] There figure 3A and the figure 3B show a model of jaw part 2 comprising the replica dentition model 1 illustrated in figures 2A et 2B and a dental prosthesis model 4, shown in hatching, assembled by digital design to the denture replica model 1.

[0088] The dental prosthesis model 4 is digitally designed based on the denture replica model 1. The profile and shape of the prosthesis model are determined according to the denture replica model 1 to ensure the best possible fit. The profile of the dental prosthesis model 4 is also determined based on an insertion axis, that is, the trajectory for inserting the simulated dental prosthesis model into the patient's mouth. This insertion axis is determined, for example, by the dental technician or by the software.

[0089] Therefore, the dental prosthesis model 4 typically includes at least one tooth, and possibly a portion of gum depending on the denture replica model 1, so as to form a jaw part model 2 with a corrected and complete dentition.

[0090] In the case of a partial denture, the denture model 4 may include a stellite framework model (not shown) configured to bear on at least one remaining tooth 5 and / or on a mucosa, in particular the gums, and / or to hold together at least two separate parts of the denture model.

[0091] It is understood that the lower portion of the jaw part model 2 corresponds in all respects to the lower portion of the denture replica model 1. Indeed, only the hatched area shown on the jaw part model 2 differs from the denture replica model 1. Thus, the jaw part model 2 also includes the lower surface 7 at its lower end. Consequently, the jaw part model 2 also includes the positioning member model 8, which here includes the groove 8a and the stop 8b, identical to the positioning member of the denture replica model 1.

[0092] There figure 4 illustrates a positioning step of the jaw part 20 on a shell 32 of a shell mold 30. The shell mold 30 here comprises two shells: the shell 32 and a complementary shell 34 which is configured to cooperate with the shell 32 to close the shell mold 30.

[0093] To this end, the shell 32 and the complementary shell 34 respectively have a notch 33a and a hook 33b. The hook 33b is configured to cooperate with the notch 33a to keep the shell mold 30 closed. Of course, any other means of closing the shell mold 30 can be considered, such as elastic bands.

[0094] The shell 32 has a base 35. The base 35 defines a flat surface. The flat surface formed by the base 35 is intended to receive the jaw part 20 on the side of its lower surface 7.

[0095] According to the example shown, pouring holes 38 are made in the complementary shell 34 in order to fill the shell mold 30 with a material for the purpose of making an impression of an insert.

[0096] The material used to make the impression is a hydrocolloid gel.

[0097] Such a mold in 30 shells constitutes, for example, a dental mitten.

[0098] There figure 4 also shows an example of the realization of jaw part 20, made from the jaw part 2 model shown in figures 3A et 3B .

[0099] Jaw part 20, for example, is manufactured using additive manufacturing. For instance, jaw part 20 is made from PA 12 or from a light-curing resin. In the implementation example described here, jaw part 20 is manufactured as a single piece.

[0100] The manufacturing step for jaw part 20 may also include, for example, a finishing sub-step. However, parts produced by additive manufacturing generally require very little or no finishing; such a finishing step is therefore optional.

[0101] According to an interesting aspect of the invention, the shell 32 includes a complementary positioning element 36.

[0102] The complementary positioning member 36 of the shell 32 is configured to cooperate with a positioning member formed in an insert to be overmolded, to create a sliding connection. In the embodiment shown, the complementary positioning member 36 forms the male part of a dovetail joint.

[0103] The complementary positioning member 36 includes an axial stop 36b to stop the translational movement of the jaw part 20 during the cooperation of the complementary positioning member 36 with the positioning member 28. Generally in this description, an "insert" means an object intended to be inserted into a mold for overmolding.

[0104] In the context of this example, the insert considered is therefore the jaw part 20.

[0105] As shown by figure 5 The jaw portion 20 includes a positioning member 28. The positioning member 28 is based on the design of the positioning member 8. In this case, the positioning member 28 has a groove 28a. According to the example shown, the positioning member 28 also has a stop 28b formed at the front part of the jaw portion 20.

[0106] The complementary positioning organ 36 of the shell 32 is therefore configured to cooperate with the positioning organ 28 of the jaw part 20.

[0107] The complementary positioning element 36 is located on the bottom 35 of the shell 32. In particular, the complementary positioning element 36 protrudes from the bottom 35 of the shell 32.

[0108] According to the example shown, the complementary positioning member 36 here includes a tab 36a, which has a shape complementary to that of the groove 28a. The tab 36a has, for example, a cross-section complementary to the cross-section of the groove 28a.

[0109] The tongue 36a projects from the base 35 of the shell 32. The tongue extends longitudinally along the axis G shown on the figure 5 The longitudinal axis G of the tongue 36a is parallel to the flat surface formed by the bottom 35 of the shell 32 so that the translational movement obtained during the cooperation between the tongue 36a and the groove 28a takes place parallel to the flat surface formed by the bottom 35 of the shell 32.

[0110] Thus, during the cooperation between the positioning organ 28 and the complementary positioning organ 36, the jaw part 20 is moved parallel to the flat surface of the bottom 35 of the shell 32.

[0111] In the embodiment shown, groove 28a forms the female part of a dovetail joint. Groove 28a has, for example, a polygonal, or more precisely, trapezoidal cross-section. In the embodiment shown, tongue 36a forms the male part of a dovetail joint.

[0112] The dovetail joint here serves to prevent the movement of the jaw part 20 in an out-of-plane direction, for example orthogonal to the flat surface of the bottom 35 of the shell 32, and to hold the jaw part 20 in position for example during the separation of the complementary shell 34 and the shell 32 after a step of making an impression described in more detail below.

[0113] Of course, the groove 28a of the positioning member 28 and / or the tab 36a of the complementary positioning member 36 according to the invention can be of any other shape provided they allow cooperation via a sliding connection. Thus, in an embodiment not shown, the positioning member 28 has a tab projecting from the lower surface of the jaw portion, and the complementary positioning member has a groove with a cross-section complementary to the tab of the positioning member. According to the example shown, the axial stop 36b is configured to cooperate with the positioning member 28 and more particularly with the front portion of the jaw portion 20, optionally with the stop 28b of the positioning member 28. This axial stop 36b also forms a positioning reference mark for the jaw portion 20 on the shell 32.

[0114] The axial stop 36b is formed by a projecting surface, extending perpendicularly on either side of the tongue 36a, so that the complementary positioning member 36 has a T-shape. The axial stop 36b is for example located at one end of the tongue 36a so as to be able to visualize the support against the stop with an insert, such as the jaw part 20 and in this case with the stop 28b of the positioning member 28.

[0115] Of course, the axial stop 36b of the complementary positioning member 36 is not limited to the example shown and can be formed by any other means that prevents the translational movement of an insert. In an embodiment not shown, the groove 28a formed by the positioning member 28 is blind and abuts against a longitudinal end of the tongue 36a.

[0116] There figure 6 illustrates the imprint 39 obtained after separation of the complementary shell 34 and the shell 32 bearing the jaw part 20, i.e. when the shell mold 30 is opened.

[0117] According to the example shown, the cavity 39 is formed from the material introduced through the pouring holes 38. Therefore, in the present example, the cavity 39 is fully contained within the complementary shell 34 of the shell mold 30.

[0118] As also illustrated by the figure 6 The process includes a step of drilling a feeding channel 37a, formed from at least one of the pouring holes 38 of the complementary shell 34 and opening into the impression 39. Such a feeding channel 37a is for example made using a cannula 37b, for example a hollow cannula, inserted through one of the pouring holes 38. By way of non-limitation, the feeding channel 37a preferably opens at the level of a gingival part of the impression 39.

[0119] Thus, such a process makes it possible to take an impression in order to create a custom-made dental prosthesis by molding.

[0120] There figure 7 illustrates a positioning step of at least one artificial tooth 42 in the impression 39.

[0121] For example, here, several artificial teeth 42 are positioned in the impression 39. These teeth are intended to fill the gaps, represented in the denture replica model 1. Therefore, such artificial teeth 42 are positioned in the impression 39, in the locations corresponding to the teeth previously designed by the software, as shown in hatching on the figures 3A et 3B For example.

[0122] There figure 8 shows a positioning step of a replica of teeth 10 on the shell 32 of the shell mold 30, in a manner analogous to the positioning step of the jaw part 20 on the shell 32.

[0123] For example, the replica of teeth 10 is produced by additive manufacturing, from the replica teeth model 1, in a manner analogous to the production of the jaw part 20.

[0124] The replica of the dentition 10 therefore includes a positioning organ 18, identical to the positioning organ 28 of the jaw part 20.

[0125] In this case, the positioning member 18 has a groove 18a. According to the example shown, the positioning member 18 also has a stop 18b formed by the front face of the jaw part 20.

[0126] The complementary positioning member 36 of the shell 32 is therefore configured to cooperate with the positioning member 18 of the denture replica 10. In this way, the denture replica 10 is positioned on the shell 32 in a similar, or even identical, manner to the jaw part 20. The complementary positioning member 36 is configured to form a sliding connection, and a dovetail joint, with the positioning member 18.

[0127] The sliding link allows here a translational movement of the replica of dentition 10 along the longitudinal axis G of the tongue 36a, that is to say parallel to the flat surface of the bottom 35 of the shell 32.

[0128] The dovetail joint serves to prevent the movement of the denture replica 10 in a direction perpendicular to the flat surface of the bottom 35 of the shell 32, and to hold the denture replica 10 in position for example when separating the complementary shell 34 and the shell 32 after a pouring step of a filling material described in more detail below.

[0129] There figure 9 shows a positioning step of the denture replica 10 in the impression 39. For example, this step includes a closing step of the mold into shells 30, by the cooperation of the shell 32 and the complementary shell 34, while the denture replica 10 is positioned on the shell 32 and the impression 39 is in the complementary shell 34.

[0130] The replica of teeth 10 forms a watertight bond with the impression 39. This is explained in particular by the fact that the lower part of the jaw part 20 is identical to that of the replica of teeth 10.

[0131] However, since their upper part is different, the replica of denture 10 only partially fills the impression 39, so as to form a residual volume in the impression 39. This residual volume is both defined and delimited by the impression 39, the artificial teeth 42 and the replica of denture 10.

[0132] In the case of a partial dental prosthesis, this volume is further defined by the stellite 44 framework ( figure 11 ), previously positioned on the replica of teeth 10 before the closing of the mold into shells 30.

[0133] There figure 10 illustrates a casting step in which a filling material 46 is introduced via at least one of the pouring holes 38 into the residual volume defined between at least the denture replica 10 and the impression 39. In this case, in the example shown, the filling material 46 is introduced via the feed channel 37a.

[0134] During this step, the filling material 46 comes into contact with at least part of the artificial teeth 42 to bond to them, for example, by overmolding. The same applies to the stellite framework 44 in the case of a partial denture.

[0135] The filling material 46 can be injected under pressure or by natural gravity filling, so as to best conform to the walls of the residual volume. The filling material 46 can include any type of material known for the manufacture of dental prostheses, such as an acrylic resin, for example.

[0136] The process also includes a step of separating the replica of the denture 10 and the impression 39, or even, for example, opening the mold into shells 30, then a step of extraction (not illustrated) of a blank configured to form the dental prosthesis.

[0137] The process also includes, for example, a finishing step which may include a step of removing an injection sprue corresponding to the molding of the feed channel, and / or a finishing step consisting, for example, of polishing and / or deburring and / or buffing the rough mold.

[0138] There figure 11 This illustrates an example of a prosthesis 40 obtained through this process, according to an example of implementation. In the example shown, the prosthesis 40 comprises the artificial teeth 42 and the stellite framework 44, which are bonded to the solidified filling material 46, forming a gingiva.

[0139] In this example, the dental prosthesis 40 is a partial dental prosthesis. Indeed, the stellite framework 44 connects two parts, each containing at least one artificial tooth 42 bonded to the solidified filling material 46.

[0140] Adjustment steps can be performed by positioning the dental prosthesis 40 on the denture replica 10, before it is inserted into the patient's mouth.

[0141] There figure 12 schematically illustrates an example of the implementation of a manufacturing process for a dental prosthesis according to the invention.

[0142] According to this example, the process involves: a step S1 of digital design of the dental prosthesis model to be made from the replica model of dentition 1 of a patient, as illustrated figure 1 ; a step S2, in which the positioning organ model 8 is digitally designed in the dentition replica model 1; a step S3 of parallelizing the dentition replica model 1, in which undercut areas are digitally filled; a step S4 of generating the jaw part model 2, as illustrated figures 3A et 3B comprising the denture replica model 1 and the model of the dental prosthesis assembled to said denture replica model 1; a step S5 consists of manufacturing the jaw part 20 from the jaw part model 2 including a positioning element 28, for example by additive manufacturing; a step S6 consists of manufacturing a denture replica 10 from the denture replica model 1 including a positioning element 18, for example by additive manufacturing; a step S7, as illustrated figure 4 , positioning of the jaw part 20 on a shell 32 of a shell mold 30 by cooperation of the positioning member 28 of the jaw part 20 with the complementary positioning member 36 provided in said shell 32; once the jaw part 20 is positioned on the shell 32, the shell mold 30 is closed in a step S8, illustrated by the figure 5 ; a step S9 of creating an impression 39 of the jaw part is thus carried out 20 by injecting a material into the shell mold 30. This step results in the formation of an impression 39 of the jaw part; a step S10 of drilling a feed channel opening into the impression (39); a step S11 of positioning at least one artificial tooth in the impression of the jaw part 20, as illustrated figure 7 ; an S12 step, represented for example by the figure 8 , positioning of the denture replica 10 on the shell 32 of the mold in shells 30 by cooperation of the positioning element 18 of the denture replica 10 with the complementary positioning element 36 of the shell 32; a step S13 of positioning a stellite framework 44 on the denture replica 10, when it is a partial dental prosthesis. a step S14, represented for example by the figure 9 , positioning of the denture replica 10 in the impression 39 in which at least one artificial tooth 42 is positioned; a step S15, illustrated for example figure 10 , of casting a filling material 46 into a residual volume defined by the impression 39, at least one artificial tooth 42 and the replica of dentition 10.

Claims

1. A method for manufacturing a dental prosthesis, said method comprising the following successive steps: - a step of digitally designing a dental prosthesis model (4) to be made from a dentition replica model (1) of a patient; - a step of generating a jaw part model (2) comprising the dentition replica model (1) and the dental prosthesis model (4) assembled to said dentition replica model (1); - a step of digitally designing a positioning member model (8) in the dentition replica model (1); - a step of manufacturing a jaw part (20) comprising a positioning member (28) from the jaw part model (2) including a positioning member model (8); - a step of manufacturing a dentition replica (10) comprising a positioning member (18) from the dentition replica model (1) including the positioning member model (8); - a step of positioning the jaw part (20) on a shell (32) of a shell mould (30) by cooperation of the positioning member (28) of the jaw part (20) with a complementary positioning member (36) provided in said shell (32); - a step of closing the shell mould (30); - a step of making an impression (39) of the jaw part (20) by injecting a material into the shell mould (30); - a step of positioning at least one artificial tooth (42) in the impression (39) of the jaw part (20); - a step of positioning the dentition replica (10) on the shell (32) of the shell mould (30) by cooperation of the positioning member (18) of the dentition replica (10) with the complementary positioning member (36) of the shell (32); - a step of positioning the dentition replica (10) in the impression (39) in which the at least one artificial tooth (42) is positioned, the dentition replica (10) only partially filling the impression (39), so as to form a residual volume in the impression (39); and - a step of pouring a filling material (46) into the residual volume defined by the impression (39), the at least one artificial tooth (42) and the dentition replica (10).

2. The method according to claim 1, wherein the positioning member (18, 28) cooperates in a sliding connection with the complementary positioning member (36) provided on the shell (32).

3. The method according to any one of claims 1 or 2, wherein the step of manufacturing the dentition replica (10) is preceded by a step of parallelising the dentition replica model (1), wherein undercut zones are digitally filled.

4. The method according to any one of claims 1 to 3, wherein the step of positioning the dentition replica (10) in the impression (39) is preceded by a step of positioning a stellite denture-skeleton (44) on the dentition replica (10).

5. The method according to any one of claims 1 to 4, further comprising a step of piercing a feed channel (37a) opening into the impression (39).

6. The method according to one of claims 1 to 5, wherein the step of manufacturing the jaw part (20) and / or the dentition replica (10) is carried out by additive manufacturing.

7. The method according to claim 6, wherein the step of manufacturing the jaw part (20) and / or the dentition replica (10) is carried out according to a method comprising a succession of additions of material by jets on a printing medium, in successive layers, the material being solidified by photopolymerisation after each jet.

8. A shell mould for manufacturing a dental prosthesis, wherein a shell (32) comprises a bottom (35) defining a planar surface and a complementary positioning member (36) disposed on the bottom and being configured to cooperate with a positioning member (18, 28) of an insert (10, 20) to be positioned on the bottom (35) of the shell mould (30), characterised in that said complementary positioning member (36) is configured to form a dovetail assembly with said positioning member (18, 28) preventing movement of the insert in a direction outof the plane, and in that the complementary positioning member (36) comprises an axial stop (36b).

9. The shell mould according to claim 8, characterised in that the complementary positioning member (36) is configured to form a slide connection with the positioning member (18, 28) of the insert (10, 20).

10. The shell mould according to claim 8 or 9, characterised in that said complementary positioning member (36) is configured to form a male part of the dovetail assembly.

11. The shell mould according to any one of claims 8 to 10, characterised in that said complementary positioning member (36) comprises a tongue (36a) configured to cooperate with said positioning member (18, 28).

12. The shell mould according to claim 11, characterised in that the axial stop (36b) is formed by a protruding surface, extending perpendicularly on either side of said tongue (36a), thereby giving the complementary positioning member (36) a T-shape.