Yoichi Uchiyama

Pitting corrosion for retaining acrylic resin facings

1. Pitting corrosion provides undercuts suitable for retaining a resin facing. 2. Using a cathode with a proper shape, pits were uniformly distributed on the surface of a metal casting. The size of pits varies, depending on the time of pitting treatment. 3. The retentive pits were excellent in both retentive strength and marginal sealing when compared with spherical powder and beads.

A White Band and a Transparent Zone Observed at an Interface Between a Polymerizing Polyfunctional Monomer and a Poly(Methyl Methacrylate) Rod, I

Macro- and microscopic studies were made of an interfacial microstructure which developed between a bifunctional monomer and a PMMA rod (or beads) during polymerization. The microstructure consisted of a white band and a blue transparent zone.

歯科医療にとって必須のCAD/CAMシステム : 開発の経緯と現状および将来展望

Recently, according to the change of the social environment, the opportunity for needing hand work in human life lessens. Therefore, people in the industrial world have felt the crisis to the field of producing since many years ago. And they have developed a CAD/CAM system to a wide scope, by transplanting the technology of skilled workers to the machine of controlled by computer. We had crisis to the future dental medicine occupied by hand work. Consequently, members of the School of Dentistry of Hokkaido University introduced a progressive CAD/CAM system in the industrial world, with a special view to improving the average result of dental treatment, and have begun research and development about mechanical process of crown in 1973. The characteristic of this research is that as the origin of mechanical process. We recognized the shape of teeth by the data of three dimensions not by feeling. Consequently, we researched the way of measure to get the data, developed CAD that could design to make crown form (for making crown) by the wax. In case of CAM, we applied technology of existing NC-processing machine. By the support of Japanese government and the company, we made laser-measuring equipment, CAD that could design crown form around the abutment tooth and exclusive NC processing machine. Therefore, we could make a crown precisely by only a mechanical process, instead of by hand work. Because of this research, the CAD/CAM system was put on the market by the maker and put into practical use.