Surface Evaluation of Resilient CAD/CAM ceramics after Contouring and Polishing

This in-vitro study measured the differences in surface roughness for computer assisted design/computer assisted manufacturing (CAD/CAM) resilient ceramic and CAD/CAM composite materials.

The materials included Lava Ultimate (3 M), Cerasmart (GC America), Vita Enamic (Vita Zahnfabrik), and Brilliant Crios (Coltene). One calibrated operator polished each material with three polishing sytems: spiral polishers (Diacomp FeatherLite/Brasseler), rubbercup polishers (Enhance/DentsplyCaulk), and brush-paste (Diashine/VH Technologies). Surface roughness was assessed using a confocal laser microscope (Lext OLS4000/Olympus).

A two-way ANOVA revealed statistically significant differences in mean surface roughness values (Sa) among materials and polishers. Tukey multiple comparisons showed that mean Sa values for Lava Ultimate, Enamic, Cerasmart and Brilliant Crios polished with brush-paste as well as Lava Ultimate and Cerasmart values polished with spiral polishers were not significantly different from each other.

The finished surfaces were significantly smoother than milled surfaces for all materials. The brush-paste polishing technique created the lowest surface roughness values for all CAD/CAM materials and values were comparable to what was achieved by spiral polishers for Lava Ultimate and Cerasmart. Rubber polishers did not provide a clinically smooth surface for CAD/CAM resilient ceramic/composite materials.

The results of the study indicate that polishing creates smooth surfaces for CAD/CAM resilient ceramic and CAD/CAM composite restorations.