Effects of polishing techniques on surface roughness of veneering ceramics for zirconia frameworks

The aim of this study was to compare the effect surface finishing and polishing methods on surface roughness of veneering ceramics for zirconia frameworks.35 disc-shaped specimens; (10x2mm) were prepared from each veneering ceramics (IPS e-max Ceram, Noritake-CZR and Vita-VM9) and glazed (Totally 105). Each group were randomly divided into 5 groups and performed the following procedures: G1: Glaze (Control); G2:Silicon wheel+rubber points (Shofu)+diamond polishing paste; G3: Shofu ceramic polishing kit; G4: Edenta ceramic polishing kit; G5: Eve ceramic polishing kit. From G2 up to G5; procedures were applied after the removal of glazed surface with a 25 µm finishing bur (Acurata, Germany). A profilometer (Mahr XR 2.0, GmbH, Gottingen) was used to measure arithmetic mean roughness (RA) of the surfaces. The Shofu and Edenta polishing kits produced a smoother surface than the Eve polishing kit and the other groups. No significant difference was found between G3 and G5 (p<.05). Vita-VM9 have the highest surface roughness value (p<.05).Within the limitations of this study, glazing and polishing kits have shown lower Ra values than silicon wheel, rubber points and polishing paste group. Clinically adequate smoothness may vary for the crystal contents and structure of ceramic that used.