فهرست نشریات علمی دسترسی آزاد ایران

Background and objectives: This study assessed the effect of thickness of high-translucent (HT) and super-translucent (ST) monolithic zirconia on its color, translucency, and marginal and internal adaptation. Materials and methods: Monolithic zirconia restorations were fabricated from HT and ST zirconia blanks (n=30) with 0.5-, 1- and 1.5-mm thicknesses (n=10). The color and translucency parameter (TP) was measured by a spectrophotometer, and marginal gap (MG), internal gap (IG), and occlusal gap (OG) were measured by the replica technique. Results: Zirconia type had no significant effect on TP (P=0.362) but the effect of thickness was significant (P<0.001); 1.5-mm thickness yielded the lowest and 0.5-mm thickness yielded the highest TP. Zirconia type (P<0.001) and thickness (P=0.001) had significant effects on color difference (ΔE); ST yielded significantly higher ΔE, and 0.5-mm thickness resulted in significantly lower ΔE than 1-mm (P=0.047) and 1.5-mm (P<0.001). The MG of both HT and ST increased with thickness (P<0.05). The IG of 0.5 mm-thick restorations was significantly higher than 1 mm (P=0.005) and 1.5 mm (P=0.003). In ST restorations, the difference in IG was not significant among different thicknesses (P>0.05). OG was the highest in 0.5 mm thickness. In ST restorations, minimum OG was found in 1 mm thickness. Zirconia type had no significant effect on adaptation (P>0.05). Conclusion:  Zirconia type had no significant effect on TP or adaptation. Increasing the thickness decreased TP. ΔE was lower in lower thicknesses, and ST zirconia yielded higher ΔE. Thickness had a direct correlation with MG and an inverse correlation with IG and OG.