JPS6251926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The disclosed technology belongs to the technical field of a coating liquid for reinforcing a denture base or a crown for prosthesis of missing teeth.

Therefore, in this invention, the prosthesis of the artificial tooth such as the denture base and crown is molded from a polymethyl methacrylate resin, and the prosthesis is coated to strengthen it, weaken water absorption, and prevent residual This invention relates to a reinforcing liquid for coating that prevents monomer leakage, and in particular, it can be applied and polymerized by dissolving either or both of polycarbonate resin and polysulfone resin together with glass fibers in methylene chloride, which is a solvent. This invention relates to a dental prosthesis reinforcing liquid.

As is well known, so-called dental prostheses are available as a solution to missing teeth, and crowns have been developed for artificial teeth, denture bases have been developed for pedestals, and these have been put to practical use either alone or in combination.

The material for this type of prosthesis that has been commonly used until now is polymethyl methacrylate (P), which has various advantages such as cost, ease of operation during molding, and ease of handling. ,M,M,
A) Resin products based on resins have been widely used.

However, these types of polymethyl methacrylate resins have had the following problems when used as prosthetics.

In other words, because the material is water absorbent, artificial teeth made of resin can absorb water in the acidic and humid environment in the oral cavity.
Another drawback is that wear resistance deteriorates due to water absorption during brushing and other washing during removal, while residual monomer leaks out from the denture base.
However, there was also the problem that an unpleasant odor was generated over time due to the invasion of oral bacteria due to wear.

Therefore, it has been desired to improve the oral hygiene prosthesis, which is unavoidably exposed to humid environmental conditions as described above.

To deal with this, some systems have been systemized for denture bases made of polysulfone resin and prosthetics with porcelain covers such as crowns, but the manufacturing process is extremely complicated compared to the polymethyl methacrylate resin prosthesis mentioned above. However, there are many molding devices, many processes, and cumbersome precision control, resulting in significantly high costs.Therefore, there are disadvantages that prevent it from being widely used, and as a result, the above-mentioned polymethyl methacrylate resin prosthesis The current situation is that mass production is becoming more widespread.

The purpose of this invention is to take advantage of the advantages of polymethyl methacrylate resin prostheses, which are currently widely used due to various circumstances, in view of the above-mentioned problems with the prosthesis based on the conventional technology, and to By simply applying it to the polymethyl methacrylate resin prosthesis, it can reduce water absorption, prevent the residual monomer from leaking out, and also enhance wear resistance and prevent the invasion of bacteria. The purpose of the present invention is to provide an excellent dental prosthesis reinforcing solution that suppresses the occurrence of unpleasant odors and has extremely long durability.

The structure of the present invention in accordance with the above-mentioned object is to dissolve either one or both of polycarbonate resin and polysulfone resin together with glass fibers in methylene chloride, which is a solvent, in a predetermined ratio to prepare a reinforcing liquid for coating dental prosthesis. After the reinforcing liquid is thinly applied to the prosthesis, it is polymerized in a pressurized oven at a set pressure and temperature or in the atmosphere for a set time, and the methylene chloride is volatilized to form a coating of polycarbonate resin, etc. It eliminates the water absorption of the prosthesis, prevents residual monomer from leaking out, significantly increases wear resistance, prevents the invasion of bacteria, does not emit strange odors, and does not cause any problems in color tone. This is a summary of what was done.

Next, embodiments of the present invention will be described as follows.

First example: 90g of polycarbonate resin, 10g of glass fiber,
This was dissolved in 1000 ml of methylene chloride, a solvent, to prepare a reinforcing solution.

This was applied thinly and thoroughly onto a regular denture base made of a polymethyl methacrylate resin molded product using a regular brush, and after 5 minutes, the mixture was placed in a commercially available pressurized oven at 115°C under a pressure of 4.5 kg/ ^cm2. The denture base was polymerized by drying under pressure for 20 minutes, and the solvent methylene chloride was evaporated, and a glass fiber-reinforced polycarbonate resin was hardly coated on the entire surface of the denture base.

When we compared the denture base coated with the reinforcing liquid with the untreated denture base made of polymethyl methacrylate resin, we found that after 50,000 brushings, the present invention showed no change in gloss or wear compared to the initial state. Although this was not the case, conventional products had a significant loss of luster and considerable wear.

In addition, regarding water absorption, we artificially created an acidic bacteria-containing environmental fluid that is the same as the oral environment, and placed both inside it.
When immersed for 300 hours and measured with a microweigher, the denture base according to the embodiment of this invention showed no increase in water absorption, whereas the conventional product had a 1/200 increase in water absorption.
An increase in water absorption of ~1/50g was observed.

A residual monomer leakage test was carried out using a distilled water immersion test, and while no leakage was observed in the present invention, significant leakage was observed in the conventional product.

2nd Example 10g of polysulfone resin, 7g of glass fiber were dissolved in 1000ml of methylene chloride as a solvent to make a reinforcing liquid, and this was applied thinly and thoroughly to the crown and denture base using a brush, and then exposed to the atmosphere indoors. After being left to dry for 10 hours, the same solvent, methylene chloride, is evaporated, and a hard coating of polysulfone resin reinforced with glass fibers is formed over the crown and denture base.

This was tested against conventional polymethyl methacrylate resin crowns and denture bases for hardness, water absorption, and residual monomer leakage, and the data were satisfactory as in the previous examples.

In addition, in each of the above-mentioned examples, the weight of the polycarbonate resin or polysulfone resin is preferably 5 to 90 g; if it is less than 5 g, the effect of forming a cured film cannot be expected, and if it is more than 90 g, the applied film will be thicker than necessary. Therefore, the dissolution ratio is set at 5 to 90 g per 1000 ml of methylene chloride.

For glass fiber, 0.1 to 10g is good; if it is less than 0.1g, the reinforcing effect on polycarbonate resin or polysulfon resin is weak, and if it exceeds 10g, precipitation may occur in the solution, resulting in unstable quality. This is because it is not preferable in consideration of the

Therefore, the optimum heating temperature for polymerization in a pressure oven is 100 to 115°C, and in relation to rapid drying, evaporation of dissolved methylene chloride slows down below 100°C, and above 115°C the coating liquid level decreases. This is because there is a risk that bumping may occur, which hinders the formation of a smooth lining.

Further, the optimum pressurizing force is 4 to 4.5 Kg/cm ² , since bumping will occur if it is less than 4 Kg/cm ² , and evaporation will be suppressed if it is more than 4.5 Kg/cm ² .

The optimal drying time under pressure is 15 to 20 minutes, but if it is less than 15 minutes, the evaporation of methylene chloride is insufficient, and if it is longer than 20 minutes, the pressure will be applied after the evaporation is complete.

The reason for storing the product in a pressure oven 5 minutes after application is to ensure uniform curing after application.
This is because about a minute is optimal.

Further, although 8 to 10 hours is optimal for drying in the air, a minimum of 8 hours is required due to temperature and humidity, and there is no point in drying the product if it exceeds 10 hours.

The reason for using methylene chloride as a solvent is that it has a low boiling point of 40°C, is completely harmless to the human body, easily dissolves polycarbonate resin and polysulfone resin, and does not change color tone after application. This is because polysulfone resin has good solubility, and the applied coating layer is extremely hard, does not change color tone, and is chemically stable.

This is because glass fiber is most suitable for reinforcing the polycarbonate resin and polysulfone resin.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments, and various embodiments can be adopted, such as, for example, combining polycarbonate resin and polysulfone resin and dissolving them together with glass fibers in methylene chloride.

As described above, according to the present invention, at least one of polycarbonate resin and polysulfone resin and glass fiber are used in the reinforcing liquid when the artificial dental prosthesis such as a resin tooth is a polymethyl methacrylate resin product. By using this as a coating solution for reinforcing dental prosthesis molded with polymethyl methacrylate resin dissolved in methylene chloride solvent, we have created a coating solution for reinforcing dental prosthesis molded with polymethyl methacrylate resin, which is basically the easiest to manufacture and is available in the market. The reinforcing solution is simply applied to the denture base or crown with a brush or the like, and then left to dry naturally or rapidly dried under pressure in a pressure oven to coat the entire surface of the prosthesis, and after the solvent methylene chloride evaporates. The glass fiber-reinforced coating of polycarbonate resin and polysulfonic acid resin prevents water absorption, prevents residual monomer from leaking out, increases hardness, does not change color even in an acidic and humid oral environment with many bacteria, and does not emit strange odors. Moreover, it exhibits an excellent effect of not causing any discoloration or abrasion even after repeated cleaning such as brushing.

Furthermore, since the reinforcing liquid is colorless and transparent, it does not cause any discomfort to denture bases and crowns, and has the advantage of being easy to handle as it has a low boiling point and is harmless to the human body.

Therefore, the use of polycarbonate resin and polysulfonic acid resin has the effect of preventing water absorption, which is a drawback of PMMA resin, and significantly improving wear resistance, and glass fiber only strengthens them. It has the excellent effect of becoming a reinforcing layer for the coated film itself.

Furthermore, by using methylene chloride as a solvent, it has a low boiling point of 40°C, is colorless, and is harmless to the human body, so it evaporates easily, and it also has the effect of easily dissolving the polycarbonate resin, polysulfone resin, and glass fiber.

Claims (1)

[Claims] 1. In a dental prosthesis reinforcing solution for a denture base crown made of polymethyl methacrylate resin molding, at least one of a polycarbonate resin and a polysulfone resin and glass fibers are dissolved in a methylene chloride solvent, and the solution is applied to the denture base and crown and polymerized. A dental prosthesis reinforcing liquid.