JPS62236543A - Production of thermoplastic resin bed denture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for manufacturing a thermoplastic resin denture, in particular, a method for manufacturing a thermoplastic resin preform, which comprises preparing a thermoplastic resin preform, softening it by heating, and compression molding the preform. This invention relates to a method for manufacturing dentures.

[Prior Art] In recent years, polysulfone (hereinafter referred to as
PSF), polyether sulfone (hereinafter referred to as PE
Thermoplastic resins such as polycarbonate (hereinafter referred to as S) and polycarbonate (hereinafter referred to as PC) came to be used, and dentures could now be manufactured using an injection molding method called the Raining method using these thermoplastic resins. .

[Problems to be Solved by the Invention] However, in the above method, a plaster mold made by a conventional dental method is used instead of a mold used in ordinary injection molding, so the temperature and pressure are complicated. As a result, expensive injection molding machines with complex functions and various sensors were required. Furthermore, the thermoplastic resin base denture produced by this method had the disadvantage that a considerably large residual stress was observed.

[Means for Solving the Problems] Therefore, the present invention solves the problems in the conventional method, and uses a thermoplastic resin preform for compression molding to produce a denture with low compression molding pressure and low residual stress. An object of the present invention is to provide a method for manufacturing a thermoplastic resin base denture which is easy to operate and is suitable for automating the thermoplastic resin heating softening process and compression process.

According to the present invention, the purpose is to perform the following steps (a) to
This is achieved by providing a method for manufacturing a thermoplastic resin base denture, which includes at least (d) (a) preparing in advance a thermoplastic resin preform similar to the shape of the palate and/or alveolus.

(b) After drying the lower plaster mold of the upper and lower plaster molds, the preform is drawn to a predetermined position on the lower plaster mold.

(c) The thermoplastic resin is heated and softened, and the preform is attached to the lower mold of the plaster mold while keeping the thickness of the preform substantially constant.

((1) Next, the lower plaster mold capped with thermoplastic resin and the dried upper plaster mold holding the artificial tooth are placed one on top of the other and compression molded.

In the present invention, it is important to prepare in advance a thermoplastic resin preform similar in shape to the palatal and/or alveolar regions.

That is, the thermoplastic resin used in the present invention is not particularly limited. Usually, they have a high melting point such as PSF, PC1PES, etc., and in order to soften them, it is necessary to heat them at a high temperature. In that case, since the thermoplastic resin for the denture base is placed on the plaster mold, the plaster mold is also exposed to high temperatures through the heat treatment of the thermoplastic resin. For this reason, thermal decomposition of the gypsum occurs during heat treatment of the thermoplastic resin, resulting in roughness of the gypsum surface and reduction in gypsum strength.As a result, separation of the thermoplastic resin and gypsum becomes difficult, and the gypsum is destroyed during compression molding. A phenomenon occurs. In order to prevent these phenomena, it is desirable to reduce the heat treatment temperature and time of thermoplastic resins to as low a temperature as possible and to shorten them. Not only does poor flow of the thermoplastic lead to poor denture fit, but compression molding pressure must be increased, resulting in plaster failure or large residual stresses in the denture base. . Therefore, in the present invention, by using a thermoplastic resin preform similar to a thermoplastic resin denture base, it is possible to obtain a denture base with good compatibility and low residual stress even if the flow of the thermoplastic resin is poor. It has become.

Such a thermoplastic resin preform is produced by varying the thickness of the palatal and alveolar parts to give it a predetermined shape.

Specifically, the shape of the thermoplastic resin preform is as follows: in the case of the upper jaw, the thickness of the palate is 0.5 to 2.5 mm, the thickness of the alveolar region is 4 to IO+a, and an appropriate shape is used to match the shape of the upper jaw. In the case of the lower jaw.

Since there is no palate, the plate of 4 to 1OIl+1 is made to resemble the shape of the lower jaw.

Furthermore, in the present invention, the heat treatment conditions for the thermoplastic resin are extremely important. In the present invention, is it necessary to heat-treat the thermoplastic resin to attach it to the lower plaster mold while keeping the thickness of the thermoplastic resin preform approximately constant? 300 for PSF
~380°C, preferably 340-380'C, P E
In the case of S, the temperature is 320-400°C, preferably 350-400°C.
It is necessary to heat at a temperature of 400°C (25L in case of PC) to 330°C, preferably 270 to 320°C, for 2 to 7 minutes, preferably 4 to 6 minutes.

[Example] Hereinafter, the present invention will be explained in more detail based on the example shown in the drawings.

FIG. 2 shows a schematic diagram of an apparatus for carrying out the method of the present invention, and the apparatus body 5 includes a lower plaster mold drying chamber 1, a polysulfone heating softening chamber 2, a press chamber 3, an upper plaster mold, and a drying chamber for preforms. Consists of 4 chambers, 1 drying chamber for the lower plaster mold
, the polysulfone heating softening chamber 2, and the press chamber 3 are each partitioned by a vertically movable heat insulating partition plate 11 (see Fig. 1), and a preform 6 (see Fig. 1) is placed in a drying chamber l below the plaster mold. After setting the lower mold 7, compression molding automatically starts (
Pressing) process is completed.

Next, an example of a method for manufacturing a thermoplastic resin denture according to the present invention will be explained with reference to FIG.

■First, a separating agent is applied to the upper and lower plaster molds made according to standard dental methods.

■The plaster mold upper mold 9 holding the artificial tooth 1O is placed in the drying chamber 4, and the drying temperature is 10 to 18 mm depending on the type of the artificial tooth 10 to be used.
Dry at a temperature of 0'C, and dry the lower plaster mold 7 at a temperature of 220°C in a lower plaster mold drying chamber l.

■Take out the upper plaster mold 9 from the drying chamber 4 and place it on the upper part of the press in the press chamber 3.

■ With the lower plaster mold 7 placed in the lower plaster mold drying chamber l, a polysulfone plate having a shape similar to the palate and/or the sliding part is placed at a predetermined position on the lower plaster mold 7. Set Form 6.

■After that, the following operations from ■ to ■ will be performed automatically.

- The partition plate 11 is raised and the plaster mold is moved to the lower mold 7 or the polysulfone heating softening chamber 2.

■The partition plate 11 is lowered to seal the polysulfone heating softening chamber 2, and the temperature inside the polysulfone heating softening chamber 2 rises.
The polysulfone preform 6 set on the lower plaster mold 7 is softened by heating at 380°C for 5 minutes. As a result, the preform 6 is attached to the lower plaster mold 7 while keeping its thickness substantially constant.

■The partition plate 11 is raised and moved to the lower plaster mold 7 or the press room 3.

■In the press room 3, overlap the plaster mold upper mold 9 and the plaster mold lower mold 7 installed in the upper part of the press room in the above (■), and press (
Compression molding).

■Take out the upper and lower plaster molds that have been pressed from the press room 3.

■Then, the plaster mold is cooled, the denture is indexed, the denture is removed, and the denture is polished to complete the denture.

[Effects of the Invention] As explained above, according to the method for manufacturing a thermoplastic resin base denture of the present invention, a thermoplastic resin preform similar to the shape of the palate and/or alveolus is used in advance, and a thermoplastic Since the heating and softening conditions for the resin are appropriately selected, the compression molding pressure can be kept low, and the destruction and movement of the artificial tooth during molding of the denture can be prevented as much as possible. Furthermore, it has the advantage that the thermoplastic resin can be easily placed in the plaster mold, and that the heating and softening process and compression process of the thermoplastic resin can be easily automated.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram schematically showing one embodiment of the present invention, and FIG.
The figure is a schematic diagram of an apparatus for carrying out the method of the invention. l... Lower plaster mold drying chamber, 2... Polysulfone heating softening chamber, 3... Press room, 4... Upper plaster mold and preform drying chamber, 5... Apparatus main body, 6. ... Preform, 7... Plaster mold lower mold, 8... Flask, 9
...Gypsum mold upper mold, 10...Artificial tooth, 11...Partition plate.

Claims (2)

[Claims] (1) A method for manufacturing a thermoplastic resin denture, comprising at least the following steps (a) to (d). (a) A thermoplastic resin preform similar to the shape of the palate and/or alveolus is prepared in advance. (b) After drying the lower plaster mold of the upper and lower plaster molds, place the preform at a predetermined position on the lower plaster mold. (c) The thermoplastic resin is heated and softened, and the preform is attached to the lower mold of the plaster mold while keeping the thickness of the preform substantially constant. (d) Next, a lower plaster mold capped with thermoplastic resin;
The dried plaster mold holding the artificial tooth is placed on top of the upper mold and compression molded. (2) Claim 1, wherein the thermoplastic resin is polysulfone, polycarbonate, or polyethersulfone.
A method for manufacturing a thermoplastic resin denture as described in Section 1.