JPH0523358A - Method for manufacturing denture base - Google Patents

Abstract

(57) [Summary] [Purpose] A denture made of high-quality, high-performance clasp with superplastic alloy plate that can secure an appropriate thickness in parts and can be manufactured for both upper and lower jaws. Establish a simple floor manufacturing method. [Structure] In manufacturing a denture base made of a superplastic alloy plate, after molding is performed in a state where residual natural teeth are present, the undercut portion of the residual teeth is repaired so that the rising angle of the residual tooth side surface is 90 degrees. The superplastic alloy material sheet is subjected to superplastic working using this forming die at a temperature of not less than 0 ° C, and the clasp portion is cut out from the portion corresponding to the residual teeth of the obtained formed body, or further, the superplastic At the time of processing, superplastic alloy material plates of the same material having a shape corresponding to the thick part are superposed on the "position corresponding to the thick part of the denture base" of the superplastic alloy material plate, and this superposed material plate is superplastic By performing the forming and the integration of the material plate at the same time by processing, an appropriate thickness can be partially ensured in a desired portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a denture base made of a superplastic alloy plate in which a base and a clasp (hook) are integrated by utilizing superplastic working.

[0002]

2. Description of the Related Art Conventionally, a denture base made of metal has been widely used as a denture base for supporting a denture, but this metal denture base was initially tried to be manufactured by a casting means. However, in the case of casting, there are problems that the manufacturing process is complicated and the working environment is bad, and that the obtained denture base is apt to be brittle due to the casting cavity and is heavy.

Therefore, attempts have been made to manufacture a denture base by press working an 18-8 stainless steel plate, but it is not possible to obtain precise compatibility because precise molding cannot be achieved, and compatibility with the living body is not obtained. It was not enough, and problems such as the appearance of metallic taste were pointed out.

Therefore, a metal denture base formed by superplastic forming a superplastic alloy material plate has been developed (Japanese Patent Laid-Open No. 63-63).
No. 95048, "Japanese Dental Association Magazine" Vol. 43, No. 1
No. ・ April 10, 1990 ・ See pages 13 to 21). The "superplastic working" includes Ti-6Al-4V and other [α
By utilizing the phenomenon (superplasticity phenomenon) that some alloys such as + β] type titanium alloy and [δ + γ] duplex stainless steel show abnormally high elongation under conditions such as specific temperature and deformation rate, It is a processing method that performs high-precision molding under a low load under the appearance of a phenomenon. Then, in manufacturing a denture base made of a superplastic alloy plate, one surface of the superplastic alloy material plate in a superplastic state is vacuum-suctioned, and the other surface is molded while being pressurized with an inert gas such as argon gas. A method of coining and deforming so that it fits in the mold is adopted.

The above denture base made of superplastic alloy plate is easy to manufacture and is less likely to cause product defects. Moreover, since the model shape is copied with extremely high accuracy, it is better suited to the oral cavity than the cast denture base, and is particularly excellent. In the case of a denture base made of a plastic titanium alloy plate, it was extremely lightweight and had excellent properties such as excellent compatibility with living bodies.

However, recently, the following problems have been pointed out in the denture base made of superplastic alloy plate. That is, there is no particular problem as a denture base (all denture bases) when there are no natural teeth in the mouth, but when several natural teeth remain in the mouth, this tooth is used for denture base. To fix
It is necessary to create a partial denture base in which the denture base is provided with a clasp (hook) to be joined to the remaining teeth. However, since this clasp must firmly and properly grip the residual teeth, it is important that its gripping surface has a complicated and precise shape that fits well with the relatively large irregularities of the residual tooth surface. Is. Therefore, it is difficult to manufacture the clasp by coining and the like, and it is generally manufactured by a method in which a dissimilar metal material such as a nickel-chromium alloy is cast and then shaped by electric discharge machining (for example, JP-A-2-88052). reference). Therefore, for a denture base made of a superplastic alloy plate that requires a clasp, it has been necessary to separately manufacture the denture base and the clasp and then join them by "brazing" or the like (for example, Japanese Patent Laid-Open No. 3-92148). See).

However, especially when the material of the denture base is a titanium alloy material, it is extremely difficult to bond to the casting clasp, and there is a possibility that sufficient strength cannot be obtained, and the bonded portion tends to be thick. Since the production was also complicated, such a denture base with a clasp could not be said to be practically satisfactory. Moreover, if the denture base and the clasp are made of different metals, taste changes easily occur after wearing in the oral cavity,
In addition, it was not preferable in terms of biocompatibility.
Further, the clasp produced by casting has a high occurrence rate of defective molten metal spinning and casting defects in a thin portion, which is also a problem in practical use.

It is also conceivable to fix the denture base and the clasp with a resin or the like, but in this case there is a problem in strength, and if both are dissimilar metals, there is a risk of corrosion due to electrolytic corrosion.

On the other hand, a titanium alloy plate or the like is still a difficult-to-machine material even if it is processed by utilizing the superplasticity phenomenon, and therefore, a thin plate material (as a material) is generally used as a material for a denture base in which the oral cavity shape must be accurately copied. It has been considered that only two types of superplastic titanium alloy plates having thicknesses of 0.55 mm and 0.75 mm are generally adopted). Therefore, as a denture base made of superplastic alloy plate, "upper maxillary full denture base" and "maxillary partial denture base similar to full denture base" with separate clasps have been created so far using the thin titanium alloy plate as the material. Only had a thick titanium alloy plate (double the thickness for the upper jaw)
Manufactured mandibular denture base that requires higher strength using
It was not commercially available.

From the above, the object of the present invention is to eliminate the above-mentioned problems pointed out in the conventional metal denture base, and to secure an appropriate thickness in a part, for the upper jaw, It was to establish a simple manufacturing method for a denture base made of a superplastic alloy plate with a high quality and high performance clasp that can be manufactured regardless of whether it is for the lower jaw.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted a number of tests in order to achieve the above object, and as a result, a) a superplastic alloy plate such as Ti-6Al-4V alloy is If the plate thickness is not particularly thick, it is possible to transfer the shape with high precision if the size (roughness) of natural teeth is used in processing using the superplastic phenomenon. It is also possible to copy the entire tooth shape. Therefore, after slightly shaping the molding die with the remaining natural teeth, and using this to superplastically process the superplastic alloy plate to form the denture base integrated with the natural tooth part , By removing the unnecessary part as a clasp from the natural tooth transfer part of the formed superplastic alloy plate, a clasp integrated denture base can be easily and easily obtained, b) In addition, using the superplastic phenomenon When superplastic alloy sheets of the same kind are superposed and pressure-formed when processing superplastic alloy sheets, smooth deformation proceeds under low load and the crystal structure becomes uniform even though the thickness increases due to superposition. Moreover, the superposed plates are completely joined and united to maintain the mechanical properties that are not different from a single member, and as a result, a product that is the same as that formed by molding thick plates can be obtained.
I was able to obtain new knowledge.

The present invention has been completed based on the above findings and the like. "As shown in FIG. 1, after molding in a state in which residual natural teeth exist, the under teeth of the residual teeth are removed. The cut portion is repaired so that the rising angle of the residual tooth side surface becomes 90 ° or more (step A in the figure), and superplastic working of the superplastic alloy material plate is performed using this forming die (in the figure, By incorporating the step B), the step of cutting out the clasp part from the part corresponding to the residual teeth of the obtained molded product (step C in the figure), the denture base made of a superplastic alloy plate with the clasp integrally attached can be simplified. The feature is that "the point that it can be manufactured", and further "when manufacturing the above denture base made of superplastic alloy plate, at the time of superplastic working, as shown in FIG.
"Position corresponding to thick part of denture base" of superplastic alloy material plate
And a superplastic alloy material plate of the same material having a shape corresponding to the thick portion or a shape including the thick portion (including the same size and shape as the superplastic alloy raw material plate), and the laminated raw material plate By performing superplastic working and forming and unifying the material plate at the same time, it is possible to manufacture a denture base made of a superplastic alloy plate in which a proper thickness is partially secured to a desired part with good workability. It also has a great feature in "done".

Here, as a "superplastic alloy plate" which is a material for the denture base, Ti-6Al-4V and other [α + β] are used.
Any plate material of alloy having superplasticity such as type titanium alloy and [δ + γ] duplex stainless steel and having corrosion resistance, strength and safety for dentistry may be applied.

In the present invention, the reason for repairing the "remaining teeth (tooth that engages with the clasp: hook teeth) side surface rising angle" of the forming die to be 90 ° or more prior to superplastic working is as follows. This is for preventing the superplastic alloy sheet from wrapping around the undercut portion due to the working, resulting in thinning, resulting in a decrease in strength and breaking during working. Of course, this repair may be carried out at the stage of the plaster model, and it may be copied to the molding die and used.

Incidentally, it is recommended that the contour of the clasp engaging portion shape be marked on the residual tooth (hook tooth) surface of the forming die used for superplastic working as shown in FIG. As a result, the superplastic alloy material plate is deformed so that it fits into the marking groove during superplastic working, and the marking line is transferred to the processed alloy plate, so if you cut or cut based on this line, the clasp will be cut out. Is extremely easy.
The depth of the marking line (and the thickness if possible) depends on the thickness of the superplastic alloy material plate, but is 0.1 mm or more, preferably 0.3 mm.
It is good to set the degree (the thicker the material plate, the deeper it becomes).
With this groove depth, the scribe line is clearly transferred to the alloy material plate and appears clearly as embossed grooves on the front and back surfaces of the alloy plate after processing, but the transfer becomes unclear when the groove depth is shallow. The marking line (cutting-out processing line) to this forming die may be formed by directly engraving the forming die, but it is practical to apply it at the stage of the plaster model and copy it to the forming die.

When the superplastic alloy material plates that have been superposed are subjected to superplastic working to form a denture base made of a superplastic alloy plate having a partially increased thickness portion, the superplastic alloy material plates are superposed. It is preferable to select at least the part of the residual tooth as the part. This is because a clasp that requires strength is cut out from the residual tooth portion, and it is advantageous to increase the strength by thickening this portion. Of course, if accuracy can be ensured, it is preferable to superimpose a superplastic alloy material plate on a narrow portion to be a clasp portion and to avoid waste such as increase in wall thickness of the cut portion.

When the wall thickness is to be increased, the flat plate preliminarily cut and processed into a shape corresponding to the thick wall portion is placed underneath, and the flat plate that covers the entire portion of the forming die is placed upside up. After that, it is better to follow the procedure of forming and integrating the upper and lower plates by superplastic working.

As is apparent from the above description, according to the present invention, a metal denture base in which the denture base and the clasp are integrated can be manufactured by a very simple superplastic working.
In addition, since it is easy to adjust the wall thickness, it is possible to easily manufacture the denture base for the lower jaw, which was conventionally impossible to create due to the relationship between formability and strength, by superplastic working. The method of the present invention will be described more specifically in the order of steps by taking the method for producing a superplastic titanium alloy denture base according to the present invention as an example.

[ Example of procedure for manufacturing superplastic titanium alloy denture base ] (a) Creation of plaster model While making a plaster model of the denture base by copying the affected area,
Properly remove protrusions and the like due to air bubbles on the plaster model surface (because the model surface is reproduced as it is on the inner surface of the bed), and outline the site where the denture base is set.

Next, a clasp guide line is drawn on the residual tooth (hook tooth) portion of the plaster model while taking into consideration the attachment / detachment direction of the denture and the clasp maintenance force. The clasp guide line is drawn by lightly cutting the outer circumference of the residual tooth portion (forming a streak groove of about 0.1 mm or more). The clasp leg should be connected to the relief part of the denture base. This marking line is an important working line for reproducing the molded body as per the outer peripheral line of the clasp.

Next, the required surface of the plaster model is relieved with wax so that a resin layer can be secured on the surface of the metal denture base. Further, in order to strengthen the transition portion between the resin layer and the metal denture base, a finishing line is provided for the purpose of protecting the peripheral portion of the resin layer. Furthermore, a stopper for the purpose of positioning the metal denture base plate and preventing the plate from bending during resin filling.
In order to attach, the stopper part is engraved on the plaster model according to the usual method.

Then, the undercuts of the alveolar ridge are blocked out with wax, and the undercuts existing at the boundary between the residual teeth (hook teeth) and the gingival part to be clasped are also blocked out with wax.

(B) Manufacture of Molding Mold The plaster model prepared as described above is impressed with an agar impression material or the like, and a phosphate-based investment material is poured into the molding model to form a molding mold. Next, carefully remove the occlusal surface of the "remaining tooth with the clasp guide line engraved" that is copied on the molding die, paying attention to the design line, and reduce the steps of the molding die as much as possible. Further, in order for the superplastic titanium alloy plate compact to uniformly wrap the residual teeth, cutting adjustment is performed so that the angle between the denture base portion and the residual teeth (the rising angle of the residual tooth side surface) is 90 ° or more.

The adjustment of this forming die is also important, and if a step or an undercut is severe, the clasp portion of the superplastic alloy sheet formed body that has been processed becomes thin, and the strength as a clasp is impaired. There is a risk of breaking during processing and making molding impossible.

(C) Firing of Mold The firing of the mold is carried out for the purpose of releasing the gas of the mold material and improving the strength. Firing is performed by raising the temperature from room temperature to 550 ° C. over 2 hours, then raising the temperature from 850 to 900 ° C. in 2 hours, and then maintaining the temperature within 1 hour, and then in the furnace until the temperature becomes 200 ° C. or lower. It is carried out with a heat pattern that is left to stand and cooling is completed.

(D) Forming of denture base by superplastic working Using a Ti-6Al-4V superplastic alloy plate as a material, a coining process utilizing superplasticity was carried out by a conventional method using the above-mentioned forming die, and a titanium alloy material plate was formed. Is molded according to the shape of the molding surface. Since the temperature is raised to 950 ° C in superplastic working, the mold and titanium alloy material plate are set in a container sealed in an oxygen-free state to prevent oxidation, and the temperature is raised to 950 ° C in an argon gas atmosphere. While the atmospheric gas pressure (7 ~
The titanium alloy material plate is pressed against the molding die surface at a pressure of about 9 kg / cm ² gauge) to mold. At this time, if the mold side is sucked to a negative pressure (about 0.8 kg / cm ² absolute pressure) through the breathable mold, the molding accuracy is further improved and the irregularities of the mold can be faithfully copied.

Further, when it is necessary to change the wall thickness of the titanium alloy sheet compact (for example, when the slap portion and the denture base portion supporting the denture base portion need to be thick and the denture base portion is thin) Etc.), "Molding a superplastic titanium alloy flat plate that covers the whole part of the forming die" and superimposing a "superplastic titanium alloy flat plate pre-cut into a shape corresponding to the thick part" on the lower side If set above and performing the above-mentioned superplastic working while adjusting the heating time, the thickness of a uniform material that is formed into the required shape and the superplastic titanium alloy sheets that have been superposed are joined and integrated Parting is achieved at the same time, and a titanium alloy denture base whose wall thickness is freely changed is manufactured. It goes without saying that not only local thickening but also superplastic titanium alloy plates superposed on each other over all parts and subjected to the superplastic working can achieve thickening and strengthening of the whole.
This makes it possible to easily manufacture a mandibular denture base that requires strength by utilizing superplastic working.

Further, in this case, unlike the thick-walled material plates, the laminated material plates do not significantly increase the deformation resistance at the time of molding, and the thick-walled products can be sufficiently manufactured. It is also possible to manufacture products with various wall thicknesses using the alloy plate having the specified thickness as a raw material.

FIG. 4 shows an example of the shape of a superplastic titanium alloy material plate used in the production of "a denture base having a thick clasp portion and bar portion and a thin denture base portion". Superplastic forming is carried out by superimposing the shaped material b on the lower surface of the material.

(E) Post-treatment of molded body of superplastic alloy plate molded body i) Surface treatment Back side of titanium alloy plate molded body after superplastic working (molding side)
Since a thin black coating is formed on this, the black coating is removed by sandblasting (preferably using aluminum sand).

Ii) Cutting of Excessive Part from Molded Body Excessive part of titanium alloy plate molded body may be cut using a metal scissors as before, but especially when a thick plate is used as a material. Is better to use a plasma cutting machine (electrical discharge machining or etching may be used, but the work efficiency will decrease). When performing plasma cutting, it is advisable to spray an anti-spatter agent in advance and wash it with water after completion of cutting to remove it.

Usually, after cutting off a surplus portion of about 10 mm from the design portion, cutting is performed by a lathe wheel to the vicinity of the design line. Since the marking line provided on the mold is transferred to the titanium alloy plate compact, the cutting may be performed based on this line.

After the cut surface of the titanium alloy sheet compact was corrected by the laser wheel, the shape of the cut surface was corrected by a carborundum or a hard rubber, and further finish polishing was performed to complete the adjustment of the outer peripheral portion. To do.

As described above, according to the method of the present invention, it is extremely easy to manufacture a denture base made of a clasp-integrated superplastic alloy plate having excellent performance, but if the thickness adjusting technique is applied, the strength of the clasp separate body can be improved. Not only is it possible to superplastically mold high upper and lower jaw full denture bases, but it is also possible, for example, to use a prosthesis with a thick occlusal surface (the surface where the teeth mesh with each other) that are easily worn away due to the biting force It is also possible to manufacture by plastic forming.

[0035]

[Summary of Effects] As described above, according to the present invention,
It becomes possible to easily and easily manufacture a denture base made of a superplastic alloy plate in which the denture base and the clasp are integrated, and further, a denture base made of a superplastic alloy plate having a wall thickness only in a required portion can be easily and easily manufactured. The applicable range of the superplastic coining method with good workability that could be applied only to "maxillary full denture base" or "maxillary partial denture base similar to full denture base" is It has extremely useful effects in industry, such as being expanded to all.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of “a manufacturing process of a denture base made of a superplastic alloy plate” according to the present invention.

FIG. 2 is an explanatory view of a wall thickness adjusting method in manufacturing the denture base of the present invention.

FIG. 3 is an explanatory diagram of a marking groove formed on a residual tooth surface of a molding die.

FIG. 4 shows an example of the shape of a superplastic titanium alloy material plate used in the production of “a denture base having a thickened scrub portion and bar portion and a thin denture base portion”.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenzo Maezono             Izumi, Kashima-gun, Kashima-gun, Ibaraki Prefecture             Within Shima Sogo Service Co., Ltd. (72) Inventor Junichi Yamada             Izumi, Kashima-gun, Kashima-gun, Ibaraki Prefecture             Within Shima Sogo Service Co., Ltd.

Claims (5)

[Claims] 1. After molding in a state where there are residual natural teeth, the undercut portion of the residual teeth is repaired so that the rising angle of the side surface of the residual teeth becomes 90 ° or more,
A superplastic alloy sheet characterized by including a step of performing superplastic working of a superplastic alloy material plate using this forming die and cutting out a clasp part from a portion corresponding to residual teeth of the obtained formed body. Method for manufacturing denture base. 2. A superplastic alloy material plate of the same material having a shape including the thick-walled portion is superposed on the "position corresponding to the thick-walled portion of the denture base" of the superplastic alloy raw material plate during superplastic working. The method for manufacturing a denture base made of a superplastic alloy plate according to claim 1, wherein the laminated material plate is subjected to superplastic working to simultaneously form and integrate the material plates. 3. The super-plastic working according to claim 2, wherein the super-plastic alloy material plate of the same material is superposed on the portion of the super-plastic alloy material plate corresponding to at least the residual tooth portion and subjected to super-plastic working. A method for manufacturing a denture base made of a plastic alloy plate. 4. The superplastic alloy according to claim 2, wherein the superplastic alloy material plate of the same material is superposed on a portion of the superplastic alloy material plate corresponding to at least the clasp portion and subjected to superplastic working. Method for manufacturing plate denture base. 5. The superplastic alloy according to any one of claims 1 to 4, wherein a groove having a depth of 0.1 mm or more indicating the cut-out processing line of the clasp portion is formed on the forming die. Method for manufacturing plate denture base.