JPH0362091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a manufacturing method for obtaining a good local denture base by compression molding using a thermoplastic resin.

[Prior Art] As a manufacturing method for using engineering plastics with excellent mechanical strength as denture base materials, an injection molding method has been developed, and polysulfone denture bases have been used clinically. but,
Injection molding requires an expensive injection molding process.

For this reason, a compression molding method has been developed as an inexpensive method for molding denture bases using thermoplastic resin. The method is to soften a molded product in the form of a U-shaped plate that resembles a dental arch, and then compression mold it.
There is a known method (Japanese Patent Laid-Open No. 114252/1983) in which a U-shaped thin plate resembling a dental arch is softened several times on a lower plaster model and then compression molded. .

[Problems to be Solved by the Invention] However, the shape shown in Utility Model Application No. 60-88911 requires many types of denture base materials to accommodate a wide variety of dental arch shapes. The burden on the manufacturing mold for denture base material is large. Also, JP-A-60-
In No. 114252, the U-shaped thin plate is softened in several steps, which requires manual work in a high-temperature atmosphere and requires advanced techniques. Furthermore, these methods can be used to manufacture complete denture bases, but when used to manufacture local denture bases, they have the disadvantage of causing defects due to insufficient thermoplastic resin and deviations in occlusal height due to the formation of thick burrs. be. That is, in a local denture base, there are areas where alveolar ridges are created in the dental arch, which require a large amount of thermoplastic resin, and areas where natural teeth remain, which do not require any thermoplastic resin at all. For this reason, when a local denture is made by compression molding using a denture base material that has an even thickness over the entire dental arch, a thick material must be used to secure the amount of thermoplastic resin necessary for making the alveolar ridge. During compression molding, a large amount of unnecessary thermoplastic resin will be present in the area where natural teeth remain, resulting in thicker burrs and higher occlusion. Furthermore, if the thickness of the material is reduced in order to reduce the burr, sufficient thermoplastic resin cannot be secured for alveolar ridge fabrication, and the artificial tooth may fall off or shrink due to insufficient thermoplastic resin.

Therefore, as a countermeasure for the above-mentioned trouble, there is a method in which a thermoplastic resin is placed only in the alveolar ridge production area, the connection of the alveolar ridge is determined with a paratal bar or a lingual bar, and after the thermoplastic resin is softened, compression molding is performed.

However, for local denture bases where a small number of teeth are repeatedly lost, a method of connecting the alveolar ridge with thermoplastic resin is generally adopted because of ease of manufacture. In this case, if thermoplastic resin is placed and molded only in the alveolar ridge production area, problems may occur such as insufficient resin in the floor or weld lines appearing at the joints, reducing the strength of the floor.

In order to avoid such troubles, the best method is to use an integrally molded product that matches the local denture base as the denture base molding material, but this method cannot be used for local denture bases that have extremely polymorphous shapes.

[Means for Solving the Problems] The present inventor has conducted research to overcome the numerous drawbacks of the conventional methods described above and to easily obtain a good local denture base, and as a result, the present inventors have found that tooth loss in a plaster model can be easily obtained. A resin molded product for making the alveolar ridge is placed in the area, and a thin plate of the same material for connecting the alveolar ridge is placed in the remaining tooth area.
We have discovered that by performing compression molding, it is possible to easily obtain a good local denture base, and have arrived at the present invention.

That is, according to the present invention, in a method for manufacturing a local denture base by compression molding, a thermoplastic resin molded product for producing an alveolar ridge is placed in the tooth-losing area of a plaster model, and the alveolar ridge is placed in the remaining natural tooth area. Manufacturing a local denture base by placing a thin plate made of the same material as the thermoplastic resin for connection, then softening the thermoplastic resin molded product and the thin plate, and then compressing the upper and lower plaster molds together. A method is provided.

The present invention will be explained in detail below.

In the present invention, a thermoplastic resin molded product for making the alveolar ridge is placed in the tooth-losing area of the plaster model, and a thin plate made of the same material as the resin for connecting the alveolar ridge is placed on the plaster model, and the thermoplastic resin molded product is placed on the plaster model. After softening, a local denture base is manufactured by combining upper and lower plaster molds for forming a local denture base and performing compression molding.

The shape of the resin molded product for alveolar ridge production is not particularly limited as long as it has approximately the same width as the alveolar ridge to be produced and has a sufficient amount of resin for alveolar ridge production, but is preferably It is better to have a recess at the bottom of the molded product for ease of placing it on the plaster model.

The thin plate for connecting the alveolar ridge should have a length that can connect the alveolar ridge, and a thickness that will soften sufficiently without causing burns when heated and softened and will not cause thick burrs on the remaining teeth during compression molding. things are used. The specific thickness is 1 to 5 mm, preferably 2 to 3 mm.
mm. The thin plate preferably has a shape similar to a dental arch, but it is also possible to simply use a flat plate.

During compression molding, it is possible to place the resin molded product for making the alveolar ridge and the thin plate for connecting the alveolar ridge slightly apart, but in order to increase the strength of the denture base, it is necessary to place the resin molded product for making the alveolar ridge slightly apart. It is preferable to overlap the molded product and the thin plate.

The thermoplastic resin used in the present invention does not undergo thermal deterioration due to compression molding, has an appropriate viscosity, has good moldability, and can be colored in a color similar to that of the gums. The resin is required to have appropriate rigidity and moisture resistance, as well as toughness that does not cause stress cracks during use. Therefore, polystyrene, polymethyl methacrylate, polymethyl pentene-1, transparent nylon, polyethylene terephthalate, polycarbonate,
Polyarylate, polyester carbonate, transparent ABS resin, polysulfone resin, etc. are used, but polysulfone, polyethersulfone, polycarbonate, etc. are particularly preferred because they have excellent moisture resistance, rigidity, stress cracking resistance, etc. .

[Example] The present invention will be described below based on an example shown in the drawings.

The drawing is a perspective view showing the state when the local denture base material is placed on the plaster model of the lower flask,
On top of the plaster model 1, place the alveolar ridge material 2 for the tooth-losing area.
A material for forming a local denture base is shown, which includes a thin plate 3 of 4 remaining teeth.

In FIG. 1, the material for the local denture base has a U-shaped shape approximating the dental arch, and in FIG.
shows a local denture base material formed so as to cover not only the remaining tooth 4 but also the entire surface of the plaster model 1.

[Effects of the Invention] As explained above, according to the method for manufacturing a local denture base according to the present invention, sufficient resin can be secured in the alveolar ridge, so that the artificial tooth can be reliably and firmly fixed to the alveolar ridge, and Since a thin plate for connecting the alveolar ridge is used in the remaining tooth portion, the burr can be made thinner, and the occlusal height and diameter are not disturbed. Furthermore, the molded denture base has the advantage that it has high strength, does not suffer from defects such as shrinkage, and can be easily manufactured as a local denture base.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the situation when a local denture base material having a U-shape approximating a dental arch is placed on a plaster model, and Fig. 2 shows a thin plate placed on a plaster model. It is a perspective view showing the state when the local denture base material formed so as to cover not only the remaining tooth part but the entire surface of the plaster model is placed. 1... Plaster model, 2... Alveolar ridge material, 3...
Thin plate, 4... remaining teeth.

Claims (1)

[Claims] 1. In a method of manufacturing a local denture base by compression molding, a thermoplastic resin molded product for alveolar ridge production is placed in the tooth-losing area of the plaster model, and the thermoplastic resin for alveolar ridge connection is placed in the remaining natural tooth area. A method for producing a local denture base, which comprises placing a thin plate made of the same material as above, softening the thermoplastic resin molded product and the thin plate, and then combining upper and lower plaster molds and performing compression molding.