Document Type : Original Articles

Abstract

Introduction: : One of the most important factors in survival rate of implant - supported crowns is the adaptation of crown and abutment. In this study the color matching and aesthetic evolution of anterior maxillary crowns was evaluated. Materials and Methods: For this in vitro investigation 20 CAD/CAM crowns (group 1), 20 IPS e.max crowns (group 2) and 20 metal ceramic crowns were made for the maxillary central incisor of a phantom head. The silicon replica technique was used for the measurement of marginal and internal gaps. For color matching A2 shade tab was chosen of classical VITA shade guide as a reference shade. Visual and instrumental color evaluation were done for abutment - supported crowns and those crowns without abutment support. ANOVA, Tukey HSD and Pairedt test were used for data analysis (α = 0.05). Results: The smallest marginal gap was for CAD/CAM crowns (86/07µ). Mean marginal gap for other groups had no statistically significant difference (p value = 0/916). All groups had no statistically significant difference for internal gap (p value = 0/1). For abutment supported crowns the best color matching result (visual & instrumental) was for CAD/CAM crowns. Color matching in other groups had no statistically significant difference (p value = 0/239, p value = 0/872). Color matching evaluation approved the effect of titanium abutment on the color of group 1 & 2 crowns. Conclusion: All result for all groups were clinically acceptable. The CAD/CAM crowns had the best result in both two factors. Key words: Marginal gap, Internal gap, IPS e.max, Cercon, Metal ceram, Color matching, Phantom head.