Effect of shade and sintering temperature on the translucency parameter of a novel multi-layered monolithic zirconia in different thicknesses.

Abstract

The objective of the present research was to evaluate the effect of sintering temperatures (1350°C, 1450°C, and 1600°C) of a novel multi-layered esthetic zirconia material (Katana 12Z/STML) on the grain sizes and on the translucency parameters (TP00 ) for 2 different shades (A2-A3) and 2 different thicknesses (1-1.5 mm). A total of 120 non-sintered specimens were randomly divided into three subgroups according to sintering temperatures. The TP00 and grain sizes of the sintered specimens were calculated. Statistical analyses were performed using 3-way ANOVA, 1-way ANOVA, and Tukey's post hoc tests. TP00 increased 1.2 to 1.5 times as the specimen thickness decreased from 1.5 to 1 mm (P ≤ .05). The lowest TP00 values were recorded for sintering at 1350°C for the investigated thicknesses and shades (P ≤ .05). The interaction of sintering temperature and shade was significant (P ≤ .05). Grain sizes were ordered according to sintering temperature as 1350°C < 1450°C < 1600°C (P ≤ .05). TP00 values decreased with the increase in the thickness of the monolithic zirconia. The sintering temperatures and their interaction with shade significantly affected TP00 values. The grain size increased with increasing sintering temperature. The translucency of a novel multi-layered monolithic zirconia increased with higher sintering temperatures and lower thickness. The grain size increased with the increase in the sintering temperature. The sintering temperature of 1600°C led to a significant change in translucency for shade A3.