Comparison of glaze or polish on dental porcelain's surface roughness

Surface roughness of dental restorations can reduce the biological properties and wear the opposite. The goal of this investigation was comparing these process effects on the surface roughness of porcelain. In this experimental study, 20 Noritake porcelain disks of 1 cm diameter and 2-2.5 mm thickness with non-percious metal base were fabricated. All samples were finished with medium grit silicone disk and then randomly divided into four groups (n=5). In the first group, the samples were self glazed. In the second group, the samples were polished (EVE Polisher Kit). In the third group, after self glazing with a coarse grit stone, the self glaze layer was omitted, then reglazed. The fourth group was similar to the third group, but in the end stage a polishing kit was used. Samples were evaluated with Profilometer and then with SEM. As a result of normal distribution of the data, One-Way analysis of variance (ANOVA) was used for statistical analysis. The mean roughness for the glazed group was 1.06±0.0547; the polished group, 0.92±0.1304; the reglazed group, 1.22±1304; and the polished after glaze group 1.14±0.1342. The polished and polished after glaze groups had a round shape in 100%, but the glazed and reglazed groups had a sharp shape in 60%. The polished surface is less rough compared to the glazed surface and in the polish after glaze group, the surface of the porcelain is less rough compared to the reglaze group.