The Influence of Three Different Digital Cement Spacers on the Marginal Gap Adaptation of Zirconia-Reinforced Lithium Silicate Crowns Fabricated by CAD-CAM System

Background: This study compared the influence of three different radial spacers (60,90,120 microns) on marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total 45 abutment acrylic teeth were divided into groups (60, 90, and 120 microns). In each group 15 scanned Omnicam intra oral scanner ZLS crowns ground. For unit was evaluated at four regions interest scanning electronic microscope (SEM). To compare between a one-way ANOVA with post-hoc Bonferroni test preformed (α = 0.05). Results: The 60 microns (162.99 ± 16.25 µm) spacer found significantly higher than 90 (41.85 3.57 5.3 (p < Between 90- 120-micron no difference obtained. Conclusions: showed to not clinically accepted (>120 both (<120 groups. which should be optimum CELTRA® DUO is microns.