JPH0565182B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a method for producing wax molds, resin molds, and synthetic resin molded products using a dental plaster model by coating the dental plaster model. The present invention relates to a coating agent for reinforcing the model and facilitating the separation of wax molds and the like.

(Prior art) When manufacturing a wax mold using a dental plaster model, for example, in order to manufacture a dental crown, molten wax is applied to a plaster tooth base and a wax mold in the same shape as the dental crown is formed. Conventionally, a solution of polystyrene resin was applied to the plaster model of the tooth table as a hardening agent to harden and reinforce the model, and silicone oil was applied as a mold release agent to facilitate separation of the wax mold. It was being applied.

In addition, when manufacturing complete dentures, a wax model with the same shape as the complete denture is made on a gum-shaped plaster inner mold, and then plaster is poured onto it to create an outer mold, and the outer and inner molds are opened. After washing off the wax with warm water, an aqueous solution of alginate is applied as a mold release agent to the surfaces of the outer mold and inner mold, and a mixture of acrylic resin monomer and polymer is filled into the area where the wax was poured. The mold was closed to allow the polymerization of the mixture to proceed, and then the outer and inner molds were opened to take out an acrylic resin molded product having the same shape as the wax model.

(Problems to be Solved by the Invention) Conventionally, when manufacturing dental crowns, etc., a hardening agent and a mold release agent were applied separately to a plaster model, which made the application work troublesome, and the hardening agent and mold release agent were applied separately. When polystyrene was used, the film formed by its application was too thick and the inner size of the wax mold became too large, which caused the resulting tooth crown to wobble, and silicone oil was used as a mold release agent. In some cases, the mold release effect is too strong, so when applying molten wax to make a wax mold, the area where the wax is applied is repelled and warped.To prevent this, the previously applied wax must be held down by hand. However, the next part had to be coated, making it difficult to form the wax mold.

In addition, when manufacturing complete dentures, the alginate aqueous solution applied to the plaster mold as a mold release agent to facilitate removal of the acrylic resin molded product has a high viscosity, making it difficult to apply. There was a problem in that the resulting acrylic resin molded product rattled because the coating film became thick.

The present invention is a coating agent for surface hardening of dental plaster models, which has the function of a mold release agent to facilitate the removal of wax molds, resin molds, and acrylic resin molded products, and is easy to apply. The present invention provides a coating agent for hardening the surface of a dental plaster model, which can form a thin coating film and easily form highly accurate wax molds, resin molds, and resin molded products.

(Means for Solving the Problems) The coating agent for surface curing of dental plaster models according to the present invention is characterized by being composed of a condensation polymerization type silicone resin and a volatile solvent, and having room temperature curability. As the above volatile solvent, ligroin toluene is preferred. Further, the concentration of the silicone resin component is preferably 5 to 25% by weight.

(Function) When the above coating agent is applied to the required locations on the plaster model, this coating agent absorbs moisture in the plaster model and hardens, forming a thin film on the plaster surface and covering the fine irregularities on the plaster surface. and smooth it. Therefore,
When the plaster model is reinforced and a wax mold, resin mold, or synthetic resin molded product is molded on the plaster surface, it becomes easy to release the mold. and,
Since the viscosity of the above coating agent is low, less than 1.5 cp,
It makes coating work easier, and since the coating film does not repel wax, it makes it easier to apply and mold wax molds, and the thinner coating film improves the precision of wax molds, resin molds, and molded products. do.

(Example) When molding a crown-shaped wax mold on a gypsum tooth table for manufacturing a dental crown, a ligroin/toluene solution of a commercially available condensation polymerization type silicone resin (Toray, Dow Corning, Manufactured by Silicone Co., Ltd., SR2410 resin, concentration 23%, viscosity
1.2 cp) was applied once and allowed to stand at room temperature for 15 minutes to harden, forming a resin film with a thickness of 1 μm. This thickness is
This is one-fifth of the 5μ film thickness formed by applying a conventional hardening agent made of polystyrene.

Painted and unpainted parts of the tooth table above (gypsum surface)
The surface roughness of the sample was measured using a surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd., and the results shown in FIG. 1 were obtained. As shown in FIG. 1, the surface of the coated area A is significantly smoother than that of the uncoated area B. In addition, when the hardness before and after the above application was measured using a Brinell hardness meter (manufactured by Shimadzu Corporation), the Brinell hardness before application was 40, while the Brinell hardness after application was 48. . After the above application, wax was applied on top of it to create a dental crown mold. There was no need to press the waxed area by hand as in the past, and the wax mold could be easily molded. Ta. Moreover, the wax mold after molding could be easily removed from the tooth base.

Next, in order to manufacture complete dentures, an inner mold of the shape of the jaw is made with plaster, wax is applied to the surface of the inner mold, and resin teeth are attached to create a wax model with the same shape as the complete denture. After applying soapy water to release the mold, plaster was poured on top to create the outer mold. Next, the above-mentioned outer mold and inner mold are divided, the wax model is poured out with warm water, the surface of the above-mentioned outer mold and inner mold is coated once with the above-mentioned condensation polymerization type silicone resin ligroin/toluene solution, and the mixture is heated to room temperature. Leave it for 15 minutes to harden. continue,
The recesses created by pouring out the wax are filled with a mixture of acrylic resin monomers and polymers, the inner and outer molds are put together again, and heated by immersion in 100°C warm water for 40 minutes. After completing polymerization and cooling to room temperature, the outer and inner molds were separated and the complete denture was taken out.

In this case, by applying the ligroin/toluene solution of the condensation polymerization type silicone resin to the outer and inner molds, the plaster outer and inner molds will be hardened and their surfaces will become smooth, allowing the complete denture to be removed. It was easy. The viscosity of the above ligroin toluene solution at 25℃ is
The viscosity of a conventional alginate aqueous solution is 1.2cp
Since it was lower than 50 cp, its application was extremely easy. In addition, the thickness of the coating film is 1μ,
When using a conventional alginate aqueous solution
It was 1/10 compared to 10μ, and a high-precision complete denture with no rattling was obtained.

(Effects of the Invention) The coating agent of the present invention is composed of a condensation polymerization type silicone resin and a volatile solvent, and has room temperature curability. Absorbs moisture and hardens, and forms a thin film on the plaster surface to make the plaster surface smooth, and when this plaster model is used to mold wax molds, resin molds, or synthetic resin molded products, the mold release Make it easier. Since the viscosity is low, it is easy to apply, and the thickness of the coating film is thinner, which improves the accuracy of wax molds and molded products.Furthermore, the coating film does not repel wax, so it is easy to apply. Easy to apply and mold.

[Brief explanation of drawings]

The drawing is an enlarged sectional view showing the surface roughness of the plaster model.

Claims (1)

[Claims] 1. A coating agent for surface curing of dental plaster models, which is composed of a condensation polymerization type silicone resin and a volatile solvent, and is curable at room temperature.