EFFECT OF SINTERING TEMPERATURE ON LIGHT TRANSMISSION OF ZIRCONIUM CORE MATERIALS

Abstract

Background and Aim: Translucency of zirconium is important to achieve aesthetic natural results. Sintering temperature has critical effects on translucency of zirconium. The purpose of the in vitro study was to evaluate the effect of different sintering temperature on the translucency of two different zirconium framework materials. Materials and Methods: 16 mm diameter and 1.25±0.05 mm thickness (Katana) and 16 mm diameter and 1.20±0.05 mm (White-Peaks) presintered blocks were prepared, divided into 2 main groups according zirconium core materials, and 6 subgroups (n=10) according to final sintering temperatures (1400 o C, 1500 o C, and 1600 o C). To assess translucency, a spectral reflectance was measured at wavelengths of 190 nm to 1100 nm at 10-nm intervals by using a computerized spectrophotometer and in the range of 380-780 nm were chosen for statistical analysis. Sintering temperature and zirconia core materials were separately analyzed by using ANOVA in case of significant interactions. Pairwise comparisons were evaluated using the Tukey and Bonferroni post hoc tests and differences (a=.05). Results: The significant differences were found between Katana (group K) and White Peaks (group WP). While the highest Translucency Parameter (TP) value of group K was recorded at 1500 o C (0.4063 for 1400 o C, 0.532 for 1500 o C, and 0.5115 for 1600 o C), the highest TP value of group WP was recorded at 1600 o C (0.5503 for 1400 o C, 0.5266 for 1500 o C, and 0.5723 for 1600 o C). Conclusions: The light transmisson of zirconium frameworks materials was affected by sintering temperature and TP increased with increasing sintering temperature.