粉末冶金法の二重冠への応用に関する研究

概要

論文の詳細を見る
It is practically difficult to properly seat the full cast crown on the prepared tooth by means of a luting cement. We have devised the double-crown system consisting of an inner crown and an outer crown to aid better seating of the crown restoration. It can minimize the elevation of the inner crown at the margin, because its open occlusal plane allows the cement slurry to easily overflow. Although the inner crown should be very thin, it is not easy to fabricate it precisely by casting. In this study, therefore, the application of the sintering procedure by powder metallurgy to the formation of the inner crown was evaluated in terms of marginal fit before and after cementation and surface aspect. The results obtained were as follows : 1. There were no significant differences in the try-in marginal fit between the full cast crown, cast inner crown and sintered inner crown. 2. Both the cast and sintered inner crowns showed a small elevation at their margins by cementation, while significantly larger elevation was found in the cast full crown. 3. The surface roughness test and SEM observation revealed no obvious differences in the metal surface aspect between the sintering and casting method procedures. It was suggested from the foregoing results that the powder metallurgy could be effectively available for easily making the inner crown in the double-crown system.
九州歯科学会の論文
1996-12-25