Studies on Grinding of Dental Non-Precious Hard Alloys

Research Project

Project/Area Number	60570908
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	補綴理工系歯学
Research Institution	Showa University
Principal Investigator	SUZUKI Ei Dental Professor, 歯学部・歯科理工学教室, 教授 (20013899)
Co-Investigator(Kenkyū-buntansha)	MIYAZAKI Takashi Dental Assistant Professor, 歯学部・歯科理工学教室, 助教授 (40175617)
Project Period (FY)	1985 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥600,000 (Direct Cost: ¥600,000)
Keywords	Elector-mechanical grinding / Electrolytic polishing / polishing / Reciprocation of wheels / 難削材 / レジノイド系砥石 / 放電焼結
Research Abstract	The electro-mechanical grinding(EMG) which uses both the ordinary rotary mechanical grinding and the electrolytic polishing was performed to grind the dental non-precious hard alloys. EMG with the grinding wheel containing TiC and CBN showed higher amount of grinding and a better grinding surface than the only ordinary rolary mechanical grinding. But because EMG is a wet grinding method with electrolyte, scattering of electrolyle by the rotary movement of the wheel caused a safty problem of the opreator and a bad manipulation and also decreased a electritic effect. To improve thes problems and make EMG more practical in a dental use reciprocation of wheels inslead of ordinary rotation of wheels was investigated. EMG with reciprocation of wheels was found to be more practical with respect of safety and manipulation and caused higher grinding efficiency. The newly developed EMG system of dental non-precions hard alloys was summarized as below. 1.This system was composed by the grinding equipment, the grinding wheel with electric conduction, DC electric source, and the dropping equipment of electrolyte. EMG can be performed efficiently with relative low current. 2. Hard alloys can be polished efficiently by the effect of electrolysis in EMG and showed a better polishin surface. Elmination of wheels also decreases in EMG. 3.In this system the wheel works as an electrode and the operator can choose the polishing part and select the suitable polishing condition in accordance with the target of polishing to adjust the current density and polishing pressure. 4.The polishing surface without degeneration and strain can be made because EMG causes less heat and pressure during Grinding.