Evaluation of the effect of different polishing systems on the surface roughness of dental ceramics

Abstract

Statement of problem

How the finishing and polishing of ceramic restorations may affect their surface properties is unclear.

Purpose

The purpose of this in vitro study was to evaluate the effect of different polishing systems on the surface roughness of dental ceramics by using a profilometer, an environmental scanning electron microscope (ESEM), and an atomic force microscope (AFM).

Material and methods

Sixty square specimens (2×14×14 mm) of 3 popular ceramic systems (monolithic zirconia and feldspathic-based ceramic containing feldspar and fluorapatite) were prepared, glazed, and assigned to 1 of the 5 groups: a control group with no additional treatment after the glaze; in the other groups, the glaze layer was removed, and the surfaces were polished by using 4 different ceramic polishing systems (OptraFine, Shofu, Meisinger, or Komet). The surface roughness was evaluated numerically by using a profilometer and visually by using an ESEM and an AFM. The data were interpreted by using 2-way ANOVA. A multiple comparison of averages was conducted by using the Tukey HSD (α=.05).

Results

The smoothest surface was obtained in the glazed group polished with the OptraFine kit, with no statistically significant difference (P=.95). The other groups showed a significant difference from the glazed one (P<.05); however, the difference among the other groups was not significantly different (P=.59).

Conclusions

After the adjustment of dental ceramics and upon removal of the glaze, the OptraFine polishing kit and paste application can be used as an alternative to glazing for the 3 ceramic types tested. It was not possible to adequately polish the ceramic surface by using the Komet polishing kit.