WO1997034543A1

WO1997034543A1 - System for implanting fixed dental prosthesis

Info

Publication number: WO1997034543A1
Application number: PCT/ES1997/000053
Authority: WO
Inventors: Mª Carmen GARCIA CASTILLO
Original assignee: Centro De Investigacion Y Desarrollo Del Titanio En Implantologia Oral, Sociedad Limitada
Priority date: 1996-03-15
Filing date: 1997-03-07
Publication date: 1997-09-25

Abstract

System for the implantation of fixed dental prosthesis, starting from a master model (9) which reproduces the jawbone (1) of the patient, including 'replicas' (8), which match with the posts (3) of the implants (2) incorporated into the jawbone (1), on said 'replicas' (8) are arranged titanium columns (10) which are joined by means of titanium bridges (11) fixed by laser welding to said columns (10), forming a frame which can be used as a base for the construction and anchoring of the prosthesis; the frame can be made from a titanium block (20) obtained by lost wax casting from a wax blocks (19), while incorporating into said block (20) false parts (15) which determine the seats, by fixing said parts by laser welding in the corresponding hollows left by elements (17) calcined by casting.

Description

SYSTEM FOR THE IMPLEMENTATION OF FIXED DENTAL PROSTHESIS

Ectentialism, total or partial, is a very widespread problem among the population, whose effects have been tried to alleviate by incorporating prosthetic prostheses, having developed solutions ranging from removable prostheses to the incorporation of fixed dentures, in realization of the latter based on bridges that are held on natural teeth, which are still preserved, or by prostheses supported by clamping implants on the patient's own jaw.

This last solution consists in placing in the application jaw some small pieces by way of screws, of a material such as titanium, constituting the implants themselves, so that once the jaw accepts these implants, in what is known as osseointegration, on them are placed pieces called pillars, on which the corresponding prosthesis will subsequently be seated and fastened.

However, for the realization of such implant-supported prostheses to be successful, it is necessary to achieve an almost exact adjustment of the prosthesis on the implants, because a not perfect enough adjustment causes the appearance of specific pressures and stresses between the prosthesis and the implants, giving rise, depending on the degree of mismatch, to problems that can result from serious consequences in the short, medium, or long term. on the contrary, a perfect fit, or within narrow limits, provides what is known as "passive fit" between prostheses and implants, which is the fundamental condition for a successful outcome, even in the long term. Now the prosthetic cannot work I directly over the patient's mouth to carry out the preparation of the prosthesis, whereby a master model, plaster or similar material is made, in reproduction of the jaw on which the implants are incorporated, to determine in said master model the exact position of the abutments of the implants incorporated in the maxilla, being carried out on that reproduction the development of the operations aimed at the elaboration of the prosthesis. The conventional solution to carry out this process is to take an impression of the jaw, after the incorporation into it of the implants destined to hold the prosthesis, to obtain the master model from plaster. In order to obtain the impression of the jaw, transfer pieces are placed on the implants incorporated therein, called "copins", which remain in the mass of the material used for printing, serving as fasteners for other parts or called "replicas"", which constitute a reflection of the implant abutments, but in cheap materials, so that said" replicas "will be included in the mass of the material of the master model, corresponding exactly to the position of the implant abutments in the maxilla.

According to the conventional method, small gold cylinders are incorporated on said "replicas" of the master model, modeling on them a wax structure, which is subsequently replaced by a metal alloy by means of a lost wax casting process, obtaining with it the base frame for the incorporation of the dental pieces of the prosthesis, by means of a suitable coating, based on ceramic, composite, etc. 5 That method has the disadvantage that the process casting, to obtain the metal alloy structure, produces contractions and dilations, whereby the accuracy of the seats determined by the gold cylinders in the positioning obtained from the master model is lost.

This alteration is also increased due to the rounding suffered by the edges of the gold cylinders themselves, due to the heat in the casting operation, making rectification of said cylinders necessary.

All this requires that the metal structure has to be reformed based on cuts and welds, in order to find the closest possible approximation to the exact settlement on the abutments of the implants located in the patient's jaw, based on a succession of repeated operations, which complicates and makes it more expensive to obtain the prosthesis, and it is very difficult to achieve an adequate fit. ^In accordance with the present invention, a new system is proposed for carrying out the implantation of said fixed dental prostheses, with which a much easier embodiment of the prostheses to be implanted is achieved, obtaining the basic framework for the dental pieces without alteration of the seats with respect to the adjustment on the master model, so that said framework is obtained directly with the "passive adjustment" that is intended, without having to make correction modifications to it. According to this system object of the invention, on the "replicas" that are held in the material of the master model are incorporated pieces by way of columns, made of titanium, which include joining bridges, also of titanium, the which join the mentioned columns by I laser welding.

A frame is thus obtained that serves as a basis for the formation or incorporation of the incorporating block of the corresponding dental pieces, said framework being with its seats in the exact position obtained on the "replicas" of the master model and therefore with respect to the pillars of the implants incorporated in the patient's jaw.

Said correspondence between the seats of the prosthesis frame and the supports defined by the

"replicas" of the master model, does not suffer in this case alteration when developing said framework, since there is no casting that results in temperatures causing possible deformations. On the other hand, all the mentioned framework of the prosthesis is constituted by a monometal titanium assembly, so that the heating by laser welding, is easily absorbed without causing deformations, due to the uniformity of the dilation of the entire assembly .

The exclusive use of titanium in the constituent block of the prosthesis frame, as well as in the implants incorporated in the jaw, confers in turn a series of advantages over the conventional system 5 that uses gold cylinders for the seats and an alloy of lower melting point for the frame made by casting, since titanium offers the following advantages over other materials: -Low specific weight. 0 -It is radiologically transparent. -Small thermal conductivity. -It looks metallic.

- Despite its relative hardness, it is nevertheless easy to work. 5 The construction of the prosthesis frame, can also be carried out, according to the same system of the invention by placing parts intended to constitute the seats, on the "replicas" of the master model, incorporating on said pieces some calcinable elements, for the determination of a block of wax on the assembly , from whose block the pieces of the seats are then removed, transforming the wax into titanium by casting the lost wax, so that on the resulting metal block the pieces of the seats are then incorporated, which are fixed by laser welding.

In this way, a metal base frame for the prostheses is obtained, in which all the above-mentioned advantages are equally fulfilled, said framework being the seats for fixing on the implants located in the jaw, perfectly established facing the adjustment on the aforementioned implants, since said seats are established directly positioned on the "replicas" of the master model during the constructive preparation, in which position they are then incorporated exactly for laser welding, after the metal block of the frame is made .

Figure 1 represents a detail of the incorporation of an implant (2) for fastening a fixed dental prosthesis.

Figure 2 is a detail like the previous one, with the maxilla (1) of application already osseointegrated on the implant (2). Figure 3 is a representation of the same detail above, with the incorporation of the corresponding implant abutment (3) for the attachment of the prosthesis to be incorporated.

Figure 4 is the same detail above, with the incorporation of a dental piece (4) on the abutment (3) of the implant (2).

Figure 5 is a detail showing the incorporation of a "copin" of transfer (5) on a pillar (3) for holding the prosthesis to be performed. Figure 6 represents in perspective a bucket

(6) Impression of the maxilla for the realization of the prosthesis to be placed.

Figure 7 is a perspective of the block (7) in which the transfer copins remain when the impression of the jaw is taken.

Figure 8 is a perspective of the master model

(9) obtained from the printing block (7), with the "replicas" (8) positioned according to the "copins"

(5), included in the molded material. Figure 9 represents the construction of a structural structural assembly, based on two columns (10) and a bridge (11), according to the system recommended.

Figure 10 corresponds to a representation like ^the previous one, indicating the elimination of excess material from the columns (10).

Figure 11 is a representation like that of Figure 9, according to an example of practical embodiment for the fixation of the prosthesis on the implants by cementing.

Figure 12 is a representation showing the incorporation of the dental pieces (4) on a support frame already made.

Figures 13 to 15 represent configurative designs of the "replicas" (8), according to non-limiting examples.

Figures 16 to 18 represent respective possible configurations of the bridges (11) between the columns (10), according to non-limiting examples. Figure 19 represents a piece (14) provided for the realization of removable prostheses removable on a fixed bridge.

Figures 20 and 21 are two non-limiting examples of cones (13) for fixing the prosthesis by cementing according to Figure 11.

Figure 22 is a representation showing the placement of seat pieces (15), with calcinable elements (17), on the replicas (8) of the master model (9) for the realization of the prosthesis frame by means of a cast block .

Figure 23 is a representation of the same previous set, with the calcinable elements (17) of the different pieces (15) joined together. Figure 24 shows the configuration of the prosthesis block on the anterior assembly, by means of a wax block (19).

Figure 25 is a representation of the previous assembly with the wax block (19) devoid of the dental pieces (4) and dotted with granules (21) of calcinable plastic.

Figure 26 is a perspective of the wax block (19) without the seat parts (15).

Figure 27 is a perspective of the titanium block (20) obtained from the wax block (19), with the seat pieces (15) fixed in the corresponding fittings.

The invention relates to a system for the implantation of fixed dental prostheses, starting from the conventional procedure that consists in placing in the jaw (1) of the patient some pieces (2) of titanium, as screws, by means of which some are constituted Implants that can be considered as new dental roots to hold the prostheses to be placed. After a period of osseointegration, the aforementioned implants (2) remain part of the jaw (1), and then, by means of another operation, extensions (3), also of titanium, which constitute pillars, are placed on said implants (2). of seat for the incorporation of the prostheses.

If it is a question of placing an isolated dental piece (4), it can be incorporated and held directly on the corresponding implant (2) without any difficulty.

However, when the prosthesis to be placed includes multiple dental pieces (4), its installation is carried out incorporating only some implants (2) for the subjection of the whole set, the dental pieces (4) being arranged on a bearing block which is the one that it is held on the implants (2), so that in a maxillary (1) totally edentulous, with five or six implants (2) they are sufficient for the subjection of the complete prosthesis.

The placement of said dental prostheses with multiple pieces (4), however, requires great precision in the adjustments of the seats on the abutments (3) of the corresponding implants (2), since any slack in a seat causes stresses and tensions originate that lead to the failure of the prosthesis.

The preparation of the prostheses must therefore be carried out on a direct reference of the seating points on the abutments (3) of the implants (2) incorporated in the patient's mouth, in order to achieve what is called "adjustment passive "with respect to the mentioned seating points, that is to say that when the prosthesis is placed, its arrangement coincides in perfect fit over all the seating points.

For this, a conventional procedure is used, which consists in taking an impression that reflects the exact arrangement of the abutments (3) of the implants (2) in the jaw (1) of the patient; for which, on the pillars (3) transfer pieces (5), called "copins" are incorporated preceeding to take an impression by means of a tray (6) filled with a semi-directed material (7), such as silicone or similar, of so that the "copins" (5) are embedded in said material (7), keeping exactly the same arrangement as in the patient's mouth. On the "copins" (5) thus included in the block of the material (7), parts (8) are coupled, which constitute exact "replicas" of the pillars (3) of the patient's mouth, corresponding to the arrangement of said pillars (3), due to the positioning determined by the transfer copins (5).

Once again, by means of plaster molding, a block (9) is obtained, in which the "replicas" (8) are fixedly included, constituting what can be considered a master model similar to the maxilla (1) of the patient, corresponding to the "replicas" (8) in an exact manner with the abutments (3) of the implants (2), whereby said "replicas" (8) serve as exact reference points for making the prosthesis. According to the invention, said preparation of the prosthesis from said master model constituted by the block (9) provided with the "replicas" (8), is carried out, in accordance with one embodiment, in the following manner: On the replicas ( 8), which can be of various shapes, respective pieces (10) are held as columns, which are then joined by bridges (11) that are laser welded to said parts (10), thus obtaining a framework in which the columns (10) constitute exact seats to coincide with "passive adjustment" on the abutments (3) of the implants (2) of the patient's mouth.

Both the columns (10) and the bridges (11) are also provided with titanium, and the columns (10) can be of any shape and size that favors their manipulation and the arrangement for joining the bridges (11), so that, once the assembly of the assembly has been carried out by means of the necessary welds, the columns (10) can be cut to eliminate the material that is not necessary.

The framework thus formed is totally unalterable in its form by manipulations, due to the strength of the material of the component parts and the consistency of the joint welds, not producing heating capable of causing deformation stresses, while the monometal titanium assembly results from uniform contractions that do not cause tensions, so that the arrangement of the seats determined by the columns (10) remains unchanged according to the reference of the "replicas" (8), in correspondence with the arrangement of the pillars ( 3) of the implants (2) in the patient's mouth.

The bridges (11) can be a regular or irregular section, with only the need for the length to be adjusted to the separation between the columns (10) to be joined.

The frame formed by the columns (10) and the bridges (11), serves as the basis for the arrangement of the dental pieces (4) to be incorporated by the prosthesis, which can be incorporated individually or in block, by means of a metal support which is fixed by laser welding and then coated with a layer of ceramic, composite, etc. The prosthesis block that is thus obtained is _M „.,„ PCT / ES97 / 00053 97/34543

eleven -

Incorporable on the abutments (3) of the implants (2) of the patient's mouth, with respect to which the columns (10) seat with "passive adjustment", the fastening can be established directly by means of screws (12), or by including intermediate cones (13) that are fixed cemented to the columns (10) and which are the ones that in this case determine the seats on the pillars (3) of the implants (2). For the securing of the fixing screws (12), it is planned to incorporate them with a gold washer, which, being a softer metal than titanium, is compressed when the tightening is done, acting as a medium insurer against loosening.

A possible construction of the prosthesis under construction on a corrugated part (14) is foreseen, for the incorporation by fitting on the bridge

(11) of a frame firmly attached to the implants

(2) from the patient's mouth, thus obtaining an arrangement with the possibility of removing the block from the prosthesis without affecting the support frame support on the implants (2).

According to one embodiment, the metal support frame on the implants (2) can be made based on a cast titanium block, with determining parts (15) of the seats on the pillars (3) incorporated in a false manner.

To do this, as can be seen in Figure 22 and following, on the "replicas" (8) of the master model (9) the pieces (15) are placed to serve as seats on the pillars (3) of the implants ( 2), which are held in the aforementioned "replicas" by means of threaded end rods (16).

On each piece (15) and its corresponding clamping rod (16) an element (17) of calcinable material is incorporated, joining all the elements (17) of the different pieces (15) by means of bars (18), also of calcinable material, which are fixed in the joints by means of bonding and reinforcement with equally synthetic resin. Once the assembly is in solidarity, the rods (16) are removed, with low length securing screws in place and the calcinable elements (17) are cut to a suitable longitudinal measure depending on the prosthesis to be constructed. On the set thus formed, a wax covering (19) is carried out, in which the dental pieces (4) are incorporated, located so as not to interfere with the elements (17), whereby an apparent set is obtained of the prosthesis to be performed, in which the wax (19) acts as a holding block for the dental pieces (4).

From this set, the dental pieces (4) are then removed, proceeding with a modeling of the wax block (19), to remove the material that is not necessary, while smoothing the outer surface; after which the block (19) is released from the "replicas" (8), the pieces (15) being removed from the seats.

The wax block (19) is then transformed into titanium, by means of a lost wax casting, thus obtaining a metal block (20) similar to the previous block (19) of wax, in which coinciding with the preexistence of the calcinable elements (17) there are corresponding holes, in which the parts (15) of the seats are fixed by laser welding, which remain in the same arrangement as they were stored in the wax block (19), since the corresponding fittings are defined precisely because of the placement of those same pieces (15) in that situation. The block (20) thus constitutes a rigid and resistant frame, on which the prosthesis configuration with incorporation of the corresponding dental pieces (4) can be made by composite or other suitable material, leaving the assembly provided with seats defined by the pieces (15) in an arrangement to adjust with due accuracy the abutments (3) of the implants (2) in the jaw (1) of application. Once the parts (1) of the seats are fixed, in the metal block (20), the accuracy of the adjustments can be verified on the "replicas" (8) of the master molding (1), or even on the pillars themselves (3 ) of the implants (2) in the patient's mouth, so that if there is any deviation in the adjustment of any of the seats, a correction can be carried out by cutting the block (20) and re-joining its parts by laser welding in the right position.

For a good grip of the configuration material to be incorporated on the metal block (20), granules (21) of calcined plastic are spread on the wax block (19) before the casting operation, which gives rise to to that after casting in the metal block (20) there are prominences that favor said grip of the configuration material to be superimposed.

Claims

1.-System for the implantation of fixed dental prostheses, characterized in that starting from a master model (9) made of plaster or similar, as reproduction of the patient's jaw (1), including some "replicas" (8) that correspond to the pillars

(3) of the fixation implants (2) incorporated in the patient's jaw itself (1), on the aforementioned

"Replicas" (8) are clamped with titanium pieces (10), by way of columns, which are joined together by bridges (11) also made of titanium, whose fixations with respect to the mentioned columns (10) are made by laser welding, in determining a framework that serves as the basis for the prosthesis, maintaining referenced seats, on the "replicas" (8), which determine exact adjustment supports on the implants (2) in the mouth of the user.

2.-System for the implantation of fixed dental prostheses, in all according to the first claim, characterized in that once the frame formed by the columns (10) and the bridges (11) is made, the component columns (10) are reduce eliminating from them all the material that is no longer necessary.

3. System for the implantation of fixed dentures, in all according to the first and second claims, characterized in that the framework formed by the columns (10) and the bridges (11), serves as a means for the incorporation of the pieces dentures (4) of the prosthesis, which can be incorporated individually, or in assemblies, by means of a metal support that is fixed by laser welding to the prosthesis frame.

4.-System for implanting prostheses fixed teeth, in all according to the first and second claims, characterized in that the block of the dental pieces (4) can be formed independently on a support piece (14) in a corrugated way, for the coupling of the block by fitting on the bridge (11) of a frame fixed on the implants (2) of the patient's mouth, with the possibility of disassembly.

5.-System for the implantation of fixed dental prostheses, in all according to the first claim, characterized in that the prosthesis support frame is realizable based on a block (20) of cast titanium, with parts (15) determinants of the seats on the pillars (3) of the implants (2) incorporated in a false manner, the mentioned pieces (15) being arranged on the "replicas" (8) of the master model (9), being placed on said pieces (15) a castable elements (17), which are joined together by rods (18), also castable, ^and l for covering the assembly by a block of wax

(19) which is then transformed separately into the metal block (20) by casting to the lost wax, the pieces (15) of the seats being fixed on said block (20) by laser welding, in the gaps left by the calcinable elements (17).

6.-System for the implantation of fixed dentures, in all according to the sixth claim, characterized in that before casting, on the wax block (19) granules (21) of calcinable plastic are spread, which < * qη place in the formation of the metal block (20) to prominences that facilitate the grip of the configurative covering material of the prosthesis.

DATA SHEET (RULE91)

ISA / ES MODIFIED CLAIMS

[received by the International Bureau on July 30, 1997 (30.07.97); claims 1-6 replaced by modified claims 1-4 (2 pages)]

1.-System for the implantation of fixed dental prostheses, of the type that are fastened on implants (2) of fixation inserted in the jaw (1) of the patient, with incorporation of extensions (3) in function of pillars of seat for the support of the prosthesis, characterized in that starting from a master model (9), made of plaster or similar, as reproduction of the patient's jaw (1), including some "replicas" (8) that correspond to the pillars ( 3) of the implants (2), on the aforementioned replicas (8) parts (10) are held as columns, which are joined together by bridges (11), whose fixations with respect to said columns ( 10) are carried out by laser welding, in determining a framework that serves as the basis for the realization of the prosthesis, whose dental pieces (4) can be incorporated individually or in assemblies, by means of a metal support that is fixed by laser welding to the said frame, said frame being obtained with referenced seats on the replicas (8), to support with an exact adjustment on the implants (2) in the mouth of the user. 2.-System for the implantation of fixed dentures, in all according to the first claim, characterized in that once the framework formed by the columns (10) and the bridges (11) is made, the component columns (10) are reduced eliminating from them all the material that is no longer necessary.

3.-System for the implantation of fixed dental prostheses, in all according to the first claim, characterized in that the support frame of the prosthesis is realizable based on a block (20) of cast titanium, with determining parts (15) of the seats on the abutments (3) of the implants (2) incorporated in a false manner, the mentioned parts (15) being arranged on the "replicas" (8) of the model master (9), placing on said pieces (15) calcinable elements (17), which are joined together by rods (18), also calcinable, for covering the whole by a block of wax

4. System for the implantation of fixed dental prostheses, in all according to the third claim, characterized in that before casting, on the wax block (19) granules (21) of calcinable plastic are spread, which give place in the formation of the metal block (20) to prominences that facilitate the grip of the configurative covering material of the prosthesis.