An in vitro investigation into the surface roughness of 2 glazed, unglazed, and refinished ceramic materials

Objective: It is common practice for clinicians to adjust the porcelain surfaces of dental prostheses. The change in surface roughness after different surface finishing techniques has attracted the attention of prosthodontists. The present study was undertaken to investigate the average surface roughness of 2 dental ceramics: IPS Empress 2 (layering glass-ceramic, Ivoclar Vivadent) and ln-Ceram/Vitadur Alpha (Vita), either glazed, unglazed, or refinished using different techniques. Method and Materials: Disks of 6-mm diameter and 2-mm thickness were prepared from IPS Empress 2 and In-Ceram Alumina/Vitadur Alpha ceramics. Specimens were finished for 1 minute to the various stages provided in the sequence of instruments in the Shofu porcelain veneer kit. The average roughness measurements were taken from each specimen with a surface roughness tester. Results: Significant differences in surface roughness were observed between the ceramics and among the finishing techniques used for both IPS Empress 2 and In-Ceram/Vitadur Alpha. It was found that unglazed IPS Empress 2 is rougher than unglazed In-Ceram/Vitadur Alpha. Conclusion: Regardless of the type of ceramic or pretreatment, any adjusted ceramic restoration should be reglazed or subjected to a finishing sequence that is followed through to a final stage of polishing with diamond paste.