EFFECT OF LOW THERMAL DEGRADATION AND VENEERING TECHNIQUES ON COLOR AND TRANSLUCENCY OF ZIRCONIA RESTORATIONS

Purpose: This study evaluated the effect of veneering techniques and aging on the color reproduction, stability and translucency of zirconia (Y-TZP) all-ceramic restorations. Materials and Methods: Thirty all ceramic crowns were constructed and divided according to their veneering technique into three groups (n = 10/group).Group 1: Translucent Zirconia milled by (fully anatomical technique), Group 2: Zirconia coping was veneered by condensing and sintering VM9 low-fusing veneering porcelain (layering technique), Group 3: Zirconia coping was veneered by heat-pressing IPS e.max ZirPress fluorapatite glass-ceramic ingots (press-on technique). Low thermal degradation (LTD) using autoclaving for 8 hours was performed. Color parameters (L*, a*, b*) of zirconia crowns were measured with Vita Easyshade Compact (VITA, Zahnfabrich H. Rauter GmbH and Co. KG). Color reproduction, color stability, contrast ratio and translucency parameter were calculated before and after aging. Two-way analysis of variance (ANOVA), followed by Tukey’s post hoc test at a significance level of p≤0.05 was performed