Finishing efficiencies of additive-manufactured Co-Cr alloy and Ti alloy clasps.

Additive-manufactured (AMed) Co-Cr and Ti alloy clasps were made with five surface treatments. Either one of a conventional freehand finishing or barrel finishing as a medium finishing process or one of a freehand, dry electrolytic, or magnetic polishings was selected as the final polishing process. After each surface treatment, the polishing efficiencies of the AMed clasps were evaluated as to surface roughness, fitness accuracy, and retentive forces. By surface treatments without using magnetic polishing, sufficient surface smoothness was observed for both alloys. Under all five treatment conditions, better fitness accuracies and sufficient retentive forces were obtained in all Co-Cr and Ti alloy clasps for clinically acceptable results. A combination of barrel finishing and dry electro-polishing can be recommended as the automatic finishing technology, replacing the freehand polishing process by dental technicians. The findings of this study will significantly reduce the workload of dental technicians.