Manufacturing process for a removable partial denture and removable partial denture

Abstract

A method for manufacturing a removable partial denture, comprising the steps of: a) manufacturing at least one monolithic block comprising an artificial tooth portion and an artificial gingiva portion, the monolithic block comprising at least one first assembly member; b) manufacturing a framework configured to support the monolithic block, the framework comprising at least one second assembly member; and c) assembling the monolithic block with the framework by interlocking the first assembly member with the second assembly member, thus forming the removable partial denture. Figure for the abstract: Fig. 4B

Description

Title of the invention: Method for manufacturing a removable partial denture and removable partial denture technical field

[0001] The present invention relates to a method for manufacturing a removable partial dental prosthesis.

[0002] It also relates to a removable partial dental prosthesis, in particular manufactured according to such a process. Prior art

[0003] A removable dental prosthesis is a prosthesis that can be removed, for example for daily maintenance or for sleeping, and then put back in place in an individual's mouth.

[0004] A “complete” dental prosthesis, commonly called dentures, refers to a prosthesis that replaces all of the natural teeth, whether of the upper jaw for an upper denture or of the lower jaw for a lower denture.

[0005] A “partial” dental prosthesis is used when it is a question of replacing only one or some of the missing natural teeth, but not all of them.

[0006] A removable partial dental prosthesis, for example of the stellite dental type, traditionally comprises a metal framework on which at least one artificial tooth is fixed using an artificial gum.

[0007] The metal frame includes one or more saddles used to support the artificial tooth or teeth and fill the edentulous space or spaces.

[0008] Stools can also allow the transmission of masticatory forces to the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis.

[0009] Stools traditionally include a retention grid formed of through orifices.

[0010] The rigid metal frame rests both on the remaining natural teeth, in particular by means of hooks which surround them, and on the mucous membranes, mainly the gums, of the individual.

[0011] The metal frame can also be supported by at least one implant present in the individual's mouth. An implant is a metal element fixed in the bone, notably by means of a screw, in order to replace the root of a tooth.

[0012] The artificial teeth of the removable partial denture are usually made of ceramic or thermoplastic polymer of the poly(methacrylate) type methyl) (PMMA) by machining techniques, and more recently, are made of resin by three-dimensional (3D) printing techniques.

[0013] These artificial teeth are usually fixed to the metal frame by a step of casting a resin, for example pink in color, which will ultimately form the artificial gum.

[0014] During this casting stage, some of the resin passes through the metal framework's retention grid so that the resin is ultimately encapsulated by the resin. Thus, when the removable partial denture is in place in the individual's mouth, a layer of resin is present between the metal framework's resin and the individual's mucous membranes, primarily the gums, such that the resin is located at a distance of approximately 0.2 to 0.5 mm from the individual's mucous membranes, primarily the gums.

[0015] The artificial gum thus plays a fundamental mechanical role insofar as it allows, on the one hand, to ensure the attachment of the artificial teeth to the metal framework, and on the other hand, to anchor the metal framework saddles to the mucous membranes, mainly the gums, of the individual.

[0016] Furthermore, once formed, this artificial gum requires a polishing step in order to obtain a surface condition that ensures comfort to the individual on the one hand, and prevents the deposition of bacteria on this artificial gum on the other.

[0017] Thus, the production of a removable partial dental prosthesis requires a great many manual tasks and is very laborious, despite the advent of digitalization in the dental field which makes it possible, for example, to simplify and improve the taking of impressions by intraoral camera, the modeling of the metal framework or the manufacturing by numerical control of the artificial teeth and the metal framework.

[0018] Even so, the final stage of manufacturing the removable partial dental prosthesis, namely the stage of assembling the artificial teeth onto the metal frame using the artificial gum, remains very dependent on manual operations.

[0019] Thus, the manufacture of a removable partial denture, and in particular the step of assembling the artificial teeth onto the metal framework, is relatively long and tedious, taking several hours. Furthermore, since this step is carried out manually, the precision of the positioning of the artificial teeth on the metal framework and repeatability remain critical aspects. Description of the invention

[0020] The present invention aims to remedy, in whole or in part, the aforementioned drawbacks.

[0021] Its object, according to a first aspect, is a method for manufacturing a removable partial dental prosthesis, comprising the following steps: a) manufacture of at least one monolithic block comprising an artificial tooth part and an artificial gum part, in particular contiguous to the artificial tooth part, the monolithic block comprising at least one first assembly element,

[0022] b) manufacturing a chassis, in particular a metal chassis, configured to support the monolithic block, the chassis comprising at least one second assembly member, then c) assembly of the monolithic block with the frame by fitting the first assembly member with the second assembly member forming the removable partial dental prosthesis.

[0023] Manufacturing a monolithic block comprising an artificial tooth part and an artificial gum part allows the assembly step of the manufacturing process to only concern two distinct elements, namely the monolithic block on the one hand, and the framework on the other hand, whereas the assembly step of the traditional manufacturing process concerns three distinct elements, namely an artificial tooth part, an artificial gum part and a framework.

[0024] Thus, the monolithic fabrication of the artificial tooth part with the artificial gum part can, on the one hand, simplify the manufacturing process and, on the other hand, reduce its duration. It can also improve the precision of the assembly step because reducing the number of elements to be assembled (two elements instead of three) eliminates a source of dimensional variation.

[0025] Furthermore, the presence of the first assembly member and the second assembly member can further improve the accuracy of the assembly step and further reduce its duration by acting as a positioning guide between the monolithic block and the chassis.

[0026] In one embodiment, the manufacturing step of at least one monolithic block involves the manufacturing of a plurality of monolithic blocks, for example two or more monolithic blocks, each monolithic block comprising an artificial tooth part and an artificial gum part and at least one first assembly member.

[0027] The monolithic block, preferably the artificial tooth part of the monolithic block, includes at least one first assembly element.

[0028] The artificial tooth part of the monolithic block may include at least one artificial tooth, and in particular several artificial teeth.

[0029] In one embodiment, the monolithic block, preferably the artificial tooth portion of the monolithic block, comprises a plurality of first organs assembly, in particular when the artificial tooth part of the monolithic block comprises a plurality of artificial teeth.

[0030] In this embodiment, the monolithic block, preferably the artificial tooth part of the monolithic block, can include as many first assembly members as there are artificial teeth present in the artificial tooth part of the monolithic block.

[0031] Preferably, each of the artificial teeth of the artificial tooth part of the monolithic block includes a first assembly element.

[0032] In one embodiment, the chassis comprises a plurality of secondary assembly members.

[0033] The manufacturing step of at least one monolithic block and the manufacturing step of the chassis can be implemented in parallel.

[0034] The manufacturing step of at least one monolithic block may include an additive manufacturing step, in particular a 3D printing step.

[0035] The additive manufacturing step, in particular the 3D printing step, may include a succession of additions of material, in particular of at least one resin, by jets onto a printing support, in successive layers, the material being preferably solidified by photopolymerization after each jet.

[0036] This type of additive manufacturing can be carried out for example using a print head comprising multiple micro-nozzles operated by a piezoelectric system (technology of the "poly jet printing" type in English).

[0037] This type of additive manufacturing allows for precise control of each voxel in terms of position and composition, and offers very high printing resolution and the ability to simultaneously print multiple materials, thus enabling the production of a monolithic object. Using this type of additive manufacturing also allows for significant time savings in the production of the monolithic block.

[0038] The “J5 DentaJet” 3D printer from Stratasys is an example of a commercially available 3D printer suitable for manufacturing the monolithic block.

[0039] The manufacturing step of at least one monolithic block may include a sub-step of manufacturing the artificial gum part in contiguity with the artificial tooth part, preferably by additive manufacturing, in particular by 3D printing.

[0040] The first assembly member can be formed in one piece with the rest of the monolithic block, preferably by additive manufacturing, in particular by 3D printing.

[0041] The monolithic block may have an internal face configured to come into contact with the chassis.

[0042] In one embodiment, the first assembly member is formed on said inner face of the monolithic block.

[0043] In one embodiment, at least part of the first assembly member is formed in the artificial tooth part of the monolithic block.

[0044] The chassis may include at least one saddle.

[0045] The term “saddle” means a part of the chassis configured to support the monolithic block.

[0046] In one embodiment, the second assembly member is formed on said saddle.

[0047] The saddle may have an external face configured to come into contact with the monolithic block, in particular with the internal face of the monolithic block.

[0048] In one embodiment, the second assembly member is formed on said external face of the saddle.

[0049] The saddle may have an inner face configured to come into contact with the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis.

[0050] In one embodiment, the saddle is without a retention grid. In this embodiment, the saddle is therefore without through holes.

[0051] Thus, unlike the saddles of the prior art previously described which are encapsulated by a resin forming the artificial gum and which are therefore at a distance from the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis, the saddle of the frame according to the invention can be in direct contact with the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis.

[0052] This can help to reduce or even eliminate the risks of allergic reactions, such as irritation phenomena, and the risks of inflammatory reactions at the level of the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis, in particular when the framework is a metallic framework, especially one based on titanium (Ti).

[0053] This can also help to limit the risk of formation of a bacterial film on the mucous membranes, mainly the gums, of the individual receiving the removable partial denture, in particular when the framework is a metallic framework, especially one based on titanium (Ti).

[0054] In one embodiment, the chassis comprises a biocompatible material, or is even made of a biocompatible material. For example, this is the case when the chassis is a metallic chassis, particularly one based on titanium (Ti).

[0055] The inner face of the saddle is preferably opposite the outer face of the saddle which is configured to come into contact with the monolithic block, in particular with the inner face of the monolithic block.

[0056] The inner face of the monolithic block and the outer face of the chassis saddle are preferably configured to come into contact with each other.

[0057] The second assembly member can be formed as a single unit with the rest of the chassis.

[0058] In one embodiment, the first assembly member and the second assembly member are of complementary shapes.

[0059] In particular, the first assembly member and the second assembly member form a complementary male-female interlocking.

[0060] Thus, during the assembly stage of the monolithic block with the chassis, the interlocking of the first assembly member with the second assembly member corresponds to a complementary male-female interlocking.

[0061] The complementary male-female interlocking may comprise a male part and a complementary female part.

[0062] The male part of the complementary male-female socket can form a pin.

[0063] The pawl can be hollow or solid.

[0064] The pin may have a cylindrical, conical, frustoconical or any other shape. It may also have a first cylindrical part which continues into a second conical or frustoconical part.

[0065] The pawn may have a circular or polygonal cross-section, for example triangular, square, rectangular, pentagonal, hexagonal, cross-shaped, star-shaped, etc.

[0066] The female part of the complementary male-female socket can form a blind orifice, in particular complementary to the pin forming the male part.

[0067] In a particular embodiment, the first assembly member forms the female part of the complementary male-female interlocking and the second assembly member forms the male part of the complementary male-female interlocking.

[0068] In one embodiment, the inner face of the monolithic block and the outer face of the frame saddle are of complementary shapes.

[0069] This means that, in addition to the presence of the first assembly member and the second assembly member forming a complementary male-female interlocking, the residual surface of the inner face of the monolithic block and the residual surface of the outer face of the frame saddle are also complementary.

[0070] Such complementarity between the residual surface of the inner face of the monolithic block and the residual surface of the outer face of the frame saddle - which This is in addition to the presence of the first assembly element and the second assembly element forming a complementary male-female interlocking - further improving the mechanical assembly between the monolithic block and the chassis.

[0071] The manufacturing process for the removable partial dental prosthesis may include a three-dimensional modeling step of the monolithic block to be manufactured and / or the frame to be manufactured.

[0072] The three-dimensional modeling step of the monolithic block and / or chassis can be implemented before the manufacturing step of at least one monolithic block and / or before the manufacturing step of the chassis.

[0073] The three-dimensional modeling step of the monolithic block and / or the chassis can allow the inner face of the monolithic block and the outer face of the chassis saddle to have complementary shapes.

[0074] In one embodiment, the inner face of the frame saddle is configured to conform to the shape of the mucous membranes, mainly the gums, of the individual with which it comes into contact.

[0075] The manufacturing process for the removable partial dental prosthesis may include a three-dimensional modeling step of the saddle of the frame to be manufactured.

[0076] The three-dimensional modeling step of the chassis saddle can be implemented before the chassis manufacturing step.

[0077] The three-dimensional modeling step of the chassis saddle can allow the inner face of the chassis saddle to be configured to fit the shape of the mucous membranes, mainly the gums, of the individual on which it comes into contact.

[0078] The manufacturing process for the removable partial dental prosthesis may include a step of fixing the monolithic block onto the frame.

[0079] The fastening step can be carried out by friction, clipping and / or snapping.

[0080] In this case, the fixing of the monolithic block on the chassis can be removable.

[0081] The fixing step can be carried out by gluing.

[0082] In this case, the fixing step includes a step of applying glue to at least one of the first assembly member and the second assembly member.

[0083] The glue application step can be implemented prior to the step of assembling the monolithic block with the chassis.

[0084] Thus, this can allow the monolithic block to be fixed by gluing to the chassis at the end of the step of assembling the monolithic block with the chassis.

[0085] The glue may be a polymerizable glue, in particular a self-polymerizing glue.

[0086] The adhesive may contain dimethacrylate and / or 2-hydroxyethyl methacrylate (HEMA).

[0087] In addition, the glue may include at least one inorganic filler.

[0088] The inorganic filler can be chosen from barium glass, ytterbium trifluoride, titanium dioxide and one of their mixtures.

[0089] The inorganic charge may include particles with a size between 0.05 and 5.0 pm, preferably between 0.10 and 4.0 µm, more preferably between 0.15 and 3.0 pm.

[0090] The inorganic charge may include particles having an average size between 0.5 and 1.5 pm, preferably between 0.6 and 1.25 pm, more preferably between 0.8 and 1.0 pm.

[0091] In one embodiment, the glue comprises a total volume quantity of inorganic filler between 10% and 60%, preferably between 20% and 50%, more preferably between 30% and 40%.

[0092] The “Multilink® Hybrid Abutment” adhesive from IVOCLAR VIVADENT is an example of a commercially suitable adhesive for fixing the monolithic block to the chassis by bonding.

[0093] The glue may be pink-purple and / or white-yellow in color.

[0094] This can reduce the visual impact of the adhesive in relation to the framework, the artificial tooth portion of the monolithic block, and / or the artificial gingival portion of the monolithic block. In particular, it can allow the color of the adhesive to blend with the color of the artificial gingival portion and / or the color of the artificial tooth portion of the monolithic block.

[0095] The manufacturing step of at least one monolithic block may include a 3D printing step of at least one material, or even at least two materials or at least three materials.

[0096] The material may include a resin, preferably suitable for use in 3D printing.

[0097] The resin may comprise a thermosetting resin and / or a self-curing resin and / or a photopolymerizing resin, preferably a photopolymerizing resin.

[0098] The resin, particularly before polymerization, may have a water absorption of less than or equal to 32 qg / mm3 according to ISO 20795-1:2013.

[0099] The resin, in particular before polymerization, may have a water absorption of less than or equal to 40 qg / mm3, preferably less than or equal to 28 qg / mm3, according to ISO 10477:2020.

[0100] The resin, in particular before polymerization, may have a solubility less than or equal to 1.6 qg / mm3, preferably less than or equal to 1.1 qg / mm3, according to ISO 20795-1:2013.

[0101] The resin preferably exhibits biocompatibility properties as required by ISO 10993-1.

[0102] The monolithic block may have an ultimate flexural strength greater than or equal to 65 MPa, preferably greater than or equal to 85 MPa, according to ISO 20795-1:2013.

[0103] The monolithic block may have an ultimate flexural strength greater than or equal to 50 MPa, preferably greater than or equal to 94 MPa, according to ISO 10477:2020.

[0104] The monolithic block may have a flexural modulus greater than or equal to 2000 MPa, preferably greater than or equal to 2300 MPa, according to ISO 20795-1:2013.

[0105] The resin may contain a coloring agent.

[0106] In one embodiment, the coloring agent comprises at least one pigment or at least one dye, preferably at least one pigment.

[0107] In one embodiment, the pigment comprises organic and / or inorganic and / or metallic particles.

[0108] In one embodiment, the pigment comprises nanometer-sized particles. For example, the average number particle diameter is less than 1 pm, in particular between 0.1 pm and 1 pm.

[0109] In one embodiment, the pigment comprises particles, in particular of nanometric size, of titanium dioxide (TiO2) and / or zinc oxide (ZnO) and / or silica (SiO2) and / or carbon black.

[0110] The colouring agent may comprise a mixture of different pigments.

[0111] The coloring agent may include a dispersing agent.

[0112] In one embodiment, the dispersing agent comprises a surfactant.

[0113] In one embodiment, the surfactant comprises a block copolymer high molecular weight polyurethane type.

[0114] In one embodiment, the dispersing agent comprises functional groups exhibiting a high affinity for the pigment of the coloring agent present in the resin.

[0115] When the colouring agent comprises a mixture of different pigments, the dispersing agent may be identical or different for each of the colouring agent pigments present in the resin.

[0116] The artificial tooth portion of the monolithic block may include an artificial dentin portion and an artificial enamel portion covering at least partially the artificial dentin portion.

[0117] The resin used for manufacturing the artificial tooth part, in particular that used for the artificial dentin portion and that used for the artificial enamel portion of the artificial tooth part, and that used for manufacturing the part Artificial gums can have the same composition and differ only in the presence or type of coloring agent. This allows for the desired shade to be adapted, firstly, for the artificial tooth portion, specifically the artificial dentin and enamel portions, and secondly, for the artificial gum portion.

[0118] The resin may be colorless, and optionally transparent or partially transparent. This may be advantageous for manufacturing the artificial enamel portion of the artificial tooth part of the monolithic block. In this case, the resin does not contain a coloring agent.

[0119] The resin may have a white color. This may be advantageous for the manufacture of the artificial dentin portion of the artificial tooth part of the monolithic block.

[0120] The resin may have a pink color. This can be advantageous for manufacturing the artificial gingival part of the monolithic block. Such a color can be achieved, for example, by the presence of a coloring agent in the resin.

[0121] The resin may be commercially available, for example under the TrueDent™ brand of Stratasys.

[0122] The manufacturing process for the removable partial dental prosthesis may include at least one step of processing the monolithic block.

[0123] At least one monolithic block processing step can be implemented after the manufacturing step of at least one monolithic block, and in particular before the step of assembling the monolithic block with the chassis.

[0124] At least one monolithic block processing step can be implemented once the monolithic block manufactured at the end of the manufacturing step of at least one monolithic block has reached a temperature less than or equal to 70°C, preferably less than or equal to 60°C, more preferably less than or equal to 50°C, and even more preferably less than or equal to 40°C.

[0125] At least one monolithic block processing step may include a step of cleaning the monolithic block manufactured at the end of the manufacturing step of at least one monolithic block, so as to remove a support material used during the manufacturing step of at least one monolithic block.

[0126] This step of cleaning the monolithic block may include a water cleaning step, for example by high-pressure water jet (of the "water-jet" type in English), and / or a step of dissolving the support material, for example in a sodium hydroxide (NaOH) solution.

[0127] At least one processing step of the monolithic block may include a photopolymerization step of the monolithic block produced at the end of the manufacturing step of at least one monolithic block, so as to finalize the process of photopolymerization of the monolithic block produced at the end of the manufacturing step of at least one monolithic block.

[0128] In one embodiment, this photopolymerization step of the monolithic block is carried out in a photopolymerization box (“curing-box” in English).

[0129] The frame may include fastening means configured to allow the removable attachment of the frame to at least one remaining natural tooth or to at least one implant of the individual receiving the removable partial dental prosthesis.

[0130] Said fixing means may include at least one hook, for example of the ring, half-ring or Roach type, configured to surround at least partially the at least one remaining natural tooth or at least one implant and ensure removable fixing of the framework, in particular by clipping effect.

[0131] The chassis manufactured during the chassis manufacturing stage can be a metallic chassis, in particular based on a chromium and cobalt alloy (CrCo) or based on titanium (Ti).

[0132] The chassis manufactured during the chassis manufacturing stage may include a polymer material, or even be made of a polymer material.

[0133] The polymer material may be a semi-crystalline thermoplastic polymer material.

[0134] The semi-crystalline thermoplastic polymer material can be selected from polyaryletherketones (PAEK), in particular polyetheretherketone (PEEK) or polyetherketoneketone (PEKK).

[0135] Pekkton® from Cendres+Métaux SA is an example of a commercially available polymer material suitable for chassis manufacturing.

[0136] Preferably, the chassis manufacturing step includes a casting or molding step, a machining step, for example from a metal wafer or metal alloy, or an additive manufacturing step, for example by 3D printing, in particular via a laser melting technique.

[0137] The frame, and in particular the saddle(s), may have surface features, such as grooves. This can improve the bonding of the monolithic block(s) to the frame.

[0138] The chassis may be pink-purple and / or white-yellow.

[0139] This can reduce the visual impact of the framework in the mouth of the individual receiving the removable partial denture, and can in particular allow the color of the framework to blend with the color of the artificial gum part and / or with the color of the artificial tooth part of the monolithic block.

[0140] In one embodiment, the chassis is colored by anodic oxidation, in particular when the chassis is a metallic chassis, especially one based on titanium (Ti).

[0141] In one embodiment, the chassis is colored by physical vapor deposition (PVD) or by chemical vapor deposition (CVD), in particular when the chassis is a metallic chassis.

[0142] When the chassis includes a polymer material, or is made of a polymer material, the polymer material can be dyed.

[0143] The invention also relates, according to another aspect, to a removable partial dental prosthesis comprising: - at least one monolithic block comprising an artificial tooth part and an artificial gum part, the monolithic block comprising at least one first assembly element, and - a chassis, in particular a metal chassis, configured to support the monolithic block, the chassis comprising at least one second assembly member, the monolithic block and the chassis being assembled by interlocking the first assembly member with the second assembly member.

[0144] The removable partial dental prosthesis may include all or part of the structural characteristics described above in the context of the implementation of the manufacturing process.

[0145] In one embodiment, the removable partial dental prosthesis is manufactured according to the process as described above.

[0146] In one embodiment, the chassis is metallic, in particular based on a chromium and cobalt alloy (CrCo) or on titanium (Ti).

[0147] In another embodiment, the chassis comprises a polymer material, or is even made of a polymer material.

[0148] The polymer material may be a semi-crystalline thermoplastic polymer material.

[0149] The semi-crystalline thermoplastic polymer material can be selected from polyaryletherketones (PAEK), in particular polyetheretherketone (PEEK) or polyetherketoneketone (PEKK).

[0150] Pekkton® from Cendres+Métaux SA is an example of a commercially available polymer material suitable for chassis manufacturing.

[0151] The artificial tooth part may include at least one artificial tooth, and in particular several artificial teeth.

[0152] The artificial gum part may be contiguous with the artificial tooth part. Brief description of the figures

[0153] The invention, according to an exemplary embodiment, will be better understood and its advantages will become more apparent upon reading the following detailed description, given by way of example and not limitation, with reference to the accompanying drawings in which:

[0154] [Fig.lA] [Fig.lA] represents a schematic and perspective view of an example of a removable partial dental prosthesis according to the prior art, before assembly;

[0155] [Fig.lB] [Fig.lB] represents a schematic and perspective view of the removable partial dental prosthesis of [Fig.lA], after assembly;

[0156] [Fig.2A] [Fig.2A] represents a schematic and perspective view of an example of a monolithic block according to the present invention;

[0157] [Fig.2B] [Fig.2B] represents another schematic and perspective view of the monolithic block of [Fig.2A];

[0158] [Fig.3A] [Fig.3A] represents a schematic and perspective view, from below, of an example of a chassis according to the present invention;

[0159] [Fig.3B] [Fig.3B] represents a schematic and perspective view of a detail of the chassis of [Fig.3A];

[0160] [Fig.3C] [Fig.3C] represents a schematic and perspective view of another detail of the chassis of [Fig.3A];

[0161] [Fig.4A] [Fig.4A] represents a schematic and perspective view, from below, of the monolithic block of [Fig.2A] and a schematic and perspective view of a detail of the chassis of [Fig.3A], before assembly;

[0162] [Fig.4B] [Fig.4B] represents a schematic and perspective front view of the monolithic block of [Fig.2A] and a schematic and perspective view of a detail of the chassis of [Fig.3A], before assembly;

[0163] [Fig.4C] [Fig.4C] represents a schematic and perspective view of the monolithic block and detail of the chassis of [Fig.4A], after assembly;

[0164] [Fig.4D] [Fig.4D] represents a longitudinal section of the assembly of [Fig.4C];

[0165] [Fig.4E] [Fig.4E] represents a cross-section of the assembly of [Fig.4C]

[0166] [Fig.5A] [Fig.5A] represents a schematic and perspective view of another example of a removable partial dental prosthesis according to the present invention, before assembly; and

[0167] [Fig.5B] [Fig.5B] represents a schematic and perspective view of the removable partial dental prosthesis of [Fig.5A], after assembly. Detailed description of the figures

[0168] Figures IA and IB represent an example of a removable partial denture 1 according to the prior art. [Fig. IA] represents the denture 1 before assembly, while [Fig. 1B] represents the denture 1 after assembly.

[0169] In [Fig.1A], the three constituent elements of the prosthesis 1 are shown, namely the artificial tooth parts 2, the artificial gum parts 3 and the framework 4, before the step of assembling these elements to form the prosthesis 1.

[0170] In [Fig. IA], a replica of the lower jaw 5 is also shown, with the prosthesis 1 configured to be placed on this replica of the lower jaw 5. The latter has nine natural teeth 6. When the prosthesis 1 is placed on this replica of the lower jaw 5, some of these natural teeth 6 will serve as support points for the framework 4.

[0171] In [Fig.1B], the three constituent elements of the prosthesis 1, namely the artificial tooth parts 2, the artificial gum parts 3 and the framework 4, are assembled to form the prosthesis 1. The latter is installed on the replica of the lower jaw 5. Thus, each of the artificial tooth parts 2 is assembled on the artificial gum parts 3, the latter allowing to mechanically connect the artificial tooth parts 2 to the framework 4.

[0172] Figures 2A and 2B show an example of a monolithic block 7 manufactured according to the process of the present invention. The monolithic block 7 comprises an artificial tooth portion including two artificial teeth 8, and an artificial gum portion 9.

[0173] The artificial tooth portion and the artificial gum portion 9 form a single monolithic block 7, and not three separate elements. Thus, the manufacture of such a monolithic block 7 eliminates the need to assemble the artificial tooth portion onto the artificial gum portion, as is the case in the prior art.

[0174] The monolithic block 7 is preferably manufactured by 3D printing, in particular by a succession of additions of photopolymerizable resin by jets onto a printing support, in successive layers, the photopolymerizable resin being in particular solidified by photopolymerization after each jet.

[0175] Preferably, the light-cured resin used for manufacturing the artificial tooth part and that used for manufacturing the artificial gum part 9 differ only in the type of coloring agent. This makes it possible to obtain a white-yellow colored artificial tooth part and a pink-purple colored artificial gum part 9.

[0176] The monolithic block 7 has an internal face 10 configured to come into contact with a chassis.

[0177] Figures 3A, 3B and 3C represent an example of chassis 11 manufactured according to the process of the present invention.

[0178] The chassis 11 can be a metallic chassis. It can be made from a chromium and cobalt alloy (CrCo) or from titanium (Ti), in particular by casting (molding), by machining, for example from a metal wafer or a metallic alloy, or by additive manufacturing, for example by 3D printing, preferably via a laser melting technique.

[0179] Alternatively, the chassis 11 comprises a polymer material, or is made of a polymer material, in particular a semi-crystalline thermoplastic polymer material, for example selected from polyaryletherketones (PAEK), in particular polyetheretherketone (PEEK) or polyetherketoneketone (PEKK).

[0180] The frame 11 includes hooks 12 configured to surround at least partially some of the remaining natural teeth of the individual receiving the removable partial dental prosthesis and to ensure removable fixation of the frame, in particular by clipping effect.

[0181] The chassis 11 includes saddles 13, which are parts of the chassis 11 configured to support the monolithic block(s) 7.

[0182] Each of these saddles 13 has an external face 13b configured to come into contact with one of the monolithic blocks 7, in particular with its internal face 10, and an internal face 13a configured to come into contact with the mucous membranes, mainly the gums, of the individual receiving the removable partial dental prosthesis.

[0183] The inner face 13a of the saddle 13 is preferably opposite the outer face 13b of the saddle 13 which is configured to come into contact with one of the monolithic blocks 7, in particular with its inner face 10.

[0184] Each of the internal faces 13a is preferably configured to conform to the shape of the mucous membranes, primarily the gums, of the individual with which it comes into contact.

[0185] To do this, the process according to the invention may include a three-dimensional modeling step of each of the saddles 13 of the frame 11 to be manufactured, prior to the manufacturing step of the frame 11.

[0186] In the example illustrated in figures 3A, 3B and 3C, each of the saddles 13 of the frame 11 has on its external face 13b two second assembly members 14.

[0187] Each of the second assembly members 14 forms, in the illustrated example, a pin, with a circular section and a truncated cone shape.

[0188] Figures 4A to 4E represent only one of the two saddles 13 of the frame 11 and the monolithic block 7 intended to be assembled on said saddle 13.

[0189] As illustrated in [Fig.4A], the monolithic block 7 has two first assembly members 15 formed in the internal face 10 of the monolithic block 7.

[0190] The artificial tooth part, in particular each of the artificial teeth 8 of the artificial tooth part of the monolithic block 7 comprises a first assembly member 15.

[0191] Indeed, the monolithic block 7 preferably comprises as many first assembly elements 15 as there are artificial teeth 8 present in the artificial tooth part of the monolithic block 7.

[0192] Each of the first assembly members 15 forms, in the illustrated example, a blind orifice.

[0193] As illustrated in particular in [Fig.4A], the first assembly members 15 and the second assembly members 14 are of complementary shapes, and in particular form complementary male-female interlockings.

[0194] Each complementary male-female interlocking comprises a male part and a complementary female part, the first assembly member 15 forming the female part of the complementary male-female interlocking and the second assembly member 14 forming the male part of the complementary male-female interlocking.

[0195] This can allow the first assembly members 15 to be fitted together with the second assembly members 14 in the direction of the arrows in [Fig.4B] so as to result in a mechanical assembly of the monolithic block 7 on the saddle 13 of the frame 11, as illustrated in figures 4C and 4D.

[0196] The mechanical assembly of the monolithic block 7 on the saddle 13 of the frame 11, enabling the formation in the end of the removable partial dental prosthesis 1 as illustrated in [Fig.4C] and 4D, is thus greatly facilitated by the interlocking of the first assembly members 15 of the monolithic block 7 with the second assembly members 14 of the frame 11.

[0197] As illustrated in particular in figures 4A, 4D and 4E, the inner face 10 of the monolithic block and the outer surface 13b of the saddle 13 of the frame 11 coming into contact with each other are complementary, which makes it possible to further improve the mechanical assembly between the monolithic block 7 and the frame 11.

[0198] To do this, the process according to the invention may include a three-dimensional modeling step of the monolithic block 7 and the chassis 11 to be manufactured, prior to the manufacturing steps of the monolithic block 7 and the chassis 11, so as to allow the inner face 10 of the monolithic block and the outer face 13b of the saddle 13 of the chassis 11 coming into contact with each other to be complementary.

[0199] Figures 5A and 5B illustrate another example of a removable partial denture 1 according to the present invention, comprising two monolithic blocks 7 and a framework 11. [Fig.5A] represents the prosthesis before assembly while [Fig.5B] represents the prosthesis 1 after assembly of the monolithic blocks 7 onto the framework 11 by interlocking the first assembly members 15 of the monolithic blocks 7 with the second assembly members 14 of the framework 11.

[0200] In figures 5A and 5B, the frame 11 is installed on a replica of a lower jaw 17 having remaining natural teeth 16, some of these teeth 16 serving as support points for the frame 11.

Claims

Demands

1. A method for manufacturing a removable partial denture (1), comprising the steps of: a) manufacturing at least one monolithic block (7) comprising an artificial tooth part and an artificial gum part (9), the monolithic block (7) comprising at least one first assembly member (15), b) manufacturing a frame (11) configured to support the monolithic block (7), the frame (11) comprising at least one second assembly member (14), and then c) assembling the monolithic block (7) with the frame (11) by interlocking the first assembly member (15) with the second assembly member (14) forming the removable partial denture (1), the monolithic block (7) comprising an inner face (10) configured to come into contact with the frame (11), the first assembly member (15) being formed on said inner face (10) of the monolithic block (7).

2. Method according to claim 1, step a) of manufacturing at least one monolithic block (7) comprising an additive manufacturing step, in particular a 3D printing step.

3. The method according to claim 2, the additive manufacturing step comprising a succession of additions of material, in particular of at least one resin, by jets onto a printing substrate, in successive layers, the material being preferably solidified by photopolymerization after each jet.

4. A method according to any one of the preceding claims, the first assembly member (15) and the second assembly member (14) being of complementary shapes.

5. Method according to claim 4, the first assembly member (15) and the second assembly member (14) forming a complementary male-female interlocking, the complementary male-female interlocking comprising a male part and a complementary female part.

6. Method according to claim 5, the first assembly member (15) forming the female part of the male-female interlocking complementary and the second assembly member (14) forming the male part of the complementary male-female joint.

7. Method according to claim 5 or 6, the male part of the complementary male-female socket forming a pin (14).

8. Method according to any one of claims 5 to 7, the female part of the complementary male-female socket forming a blind orifice (15).

9. A method according to any one of the preceding claims, the first assembly member (15) being formed in one piece with the rest of the monolithic block (7), preferably by additive manufacturing, in particular by 3D printing.

10. Method according to any one of the preceding claims, the frame (11) comprising at least one saddle (13), the second assembly member (14) being formed on said saddle (13) of the frame (11).

11. Method according to any one of the preceding claims, the second assembly member (14) being formed as one piece with the rest of the chassis (11).

12. A method according to any one of the preceding claims, comprising a step of fixing, in particular removable, the monolithic block (7) on the chassis (11) by friction, clipping and / or snapping.

13. Method according to any one of claims 1 to 11, comprising a step of fixing the monolithic block (7) to the chassis (11) by gluing.

14. Method according to claim 13, the step of fixing the monolithic block (7) on the chassis (11) comprising a step of applying glue to at least one of the first assembly member (15) and the second assembly member (14).

15. Removable partial dental prosthesis (1), in particular manufactured according to the method according to any one of the preceding claims, comprising: - at least one monolithic block (7) comprising an artificial tooth part and an artificial gum part (9), the monolithic block (7) comprising at least one first assembly member (15), and - a framework (11) configured to support the monolithic block (7), the framework (11) comprising at least one second assembly member (14), the monolithic block (7) and the chassis (11) being assembled by interlocking the first assembly member (15) with the second assembly member (14), the monolithic block (7) having an internal face (10) configured to come into contact with the chassis (11), the first assembly member (15) being formed on said internal face (10) of the monolithic block (7).

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