JPS6312042B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a dental synthetic resin filling material, particularly to a filling material blended into a synthetic resin for repairing tooth defects. [Prior Art] Traditionally, dental repair materials include metal materials such as gold, silver, and amalgam, inorganic materials such as silicate cement, zinc phosphate cement, and silicate cement, as well as polymethyl methacrylate, glycidyl methacrylate, Polymethyl methacrylate, methyl methacrylate, bisphenol A
Fused silica as a filler in plastics such as
Plastic materials made by blending powders of quartz, glass, aluminum silicate, ceramic, etc. are known (Japanese Patent Laid-Open No. 53-32994). In particular, plastic materials have high utility value as they are easy to package and handle, and can be used in dental treatment without the need for special measures. It had the disadvantage of being inferior in terms of. [Problems to be Solved by the Invention] An object of the present invention is to provide a filler that solves the above-mentioned drawback of reduced strength of plastic materials and does not cause discoloration such as black or yellow. [Means for Solving the Problems] That is, the present invention provides a method for solving problems that
Molten silicic acid powder containing 99% by weight or more of SiO ₂ and 0.05% by weight or less of Fe ₂ O ₃ and whose X-ray structure shows no reflection of α-quartz, cristobalite or tridymite, or treated with a silane coupling agent. It is made of powder of
This dental synthetic resin filling material is characterized by having a surface area of 1 m ² /g or more as determined by the BET method. The fused silicic acid used as the filler of the present invention is
It is necessary for SiO ₂ to have a high purity of 99% by weight or more, and Fe ₂ O ₃ to be 0.05% by weight or less.
If Fe ₂ O ₃ exceeds 0.05% by weight, the plastic material will discolor to black or yellow, which is not preferable. The structure of molten silicic acid determined by X-ray diffraction is α-
The purpose of the present invention cannot be met unless the material is glassy, such as quartz, cristobalite, tridymite, etc., which exhibits substantially no reflection. Molten silicic acid, in which reflections of these components are observed, does not improve the strength of plastic materials. Furthermore, the Hunter whiteness of the fused silicic acid according to the present invention is
73 or above. Hunter whiteness is less than 73,
For example, when combined with plastics such as polymethylmethacrylate and methylmethacrylate,
It is not preferable because it discolors to black or yellow. Furthermore, the fineness of the filler of the present invention requires that the surface area measured by the BET method is 1 m ² /g or more. Even if an appropriate amount of less than 1 m ² /g is mixed into plastic, the compressive strength of dental plastic material will be
Do not exceed 2000Kg/ ^cm2 . The pulverizer used in this case is not particularly limited, but any device may be used as long as it does not mix in impurities, or if it does, it can be easily separated. Specifically, a vibrating mill, a ball mill, a stamp mill, etc. are used, and the liner and media of the mill are preferably made of porcelain or corundum. Furthermore, when a treated silane coupling agent is added to plastic as a filler, the compressive strength can be further increased. As a silane coupling agent, for example, γ-glycidoxypropyltrimexysilane

[Formula] α-(3,4-epoxycyclohexyl)ethyltrimethoxysilane

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. Examples 1 to 2, Comparative Examples 1 to 8 Molten silicic acid and silica stone were pulverized using a vibrating mill made of corundum to produce the fillers shown in the table. Aluminum silicate and Aerosil are commercially available products. The above filler is not treated with a silane coupling agent, or 1% by weight of a 10% by weight aqueous solution of a silane coupling agent containing γ-glycidoxypropyltrimethoxysilane as a main component is added by a spray method, and then mixed with a blender. After 1 hour of surface treatment, 70 parts by weight and 30 parts by weight of polymethyl methacrylate (PMMA) were mixed together and cured.
The compressive strength of the cured product was measured and the coloring state was observed with the naked eye. The results are shown in the table. In the table, the compressive strength of untreated products is the result when not treated with a silane coupling agent, and the treated product is the result when treated. Further, although the coloring status is shown for the untreated product, the condition of the treated product was almost the same as that of the untreated product.

【table】

〔Effect of the invention〕

By using the dental synthetic resin filling material of the present invention, (1) it becomes a dental material with little discoloration, (2) it has high compressive strength, so if you treat your teeth with it, you will have strong teeth. It has the following effects.

Claims (1)

[Claims] 1 Hunter whiteness is 73 or more, SiO ₂ 99% by weight or more,
Consisting of fused silicic acid powder containing 0.05% by weight or less of Fe ₂ O ₃ and showing no reflection of α-quartz, cristobalite and tridymite in its X-ray structure, or a powder obtained by treating the same with a silane coupling agent, Moreover, the dental synthetic resin filling material is characterized in that its fineness is 1 m ² /g or more in terms of surface area measured by the BET method.