Spectrophotometric Comparison of the influence of Porcelain Types on shade of Metal-Ceramic Restorations

Color matching between natural teeth, shade guides and metal-ceramic restorations is a common clinical problem. Difficulties related to color matching arise from structural differences between metal-ceramic crowns and natural teeth, the limitation of range of available ceramic shades, inadequate shade guides, different type of metal alloys, and varying composition of ceramic materials.The aim of this in vitro study was to investigate the influence of various porcelains on the final color of metal-ceramic restorations. Three commercial porcelains for metal-ceramic restorations, Vita VMK95)Vident, Brea, CA, USA(, ceramco2(Dentsply, Burlington, NJ, USA(and Noritake)Noritake, Tokyo, Japan(and alloy T3(Ticonium, Division of CMP Indnstries LLC)were combined in metal-ceramic disks with standardized thickness of layeres.10 disk)10mm(were prepared for each porcelains in A3 shade. the samples were analyzed with a spectrophotometer, and data were obtained in the CLELAB color system. The recorded data were analyzed with One Way Analysis of Variance and Tukey test. The type of porcelains overlying disks had significant effect on color of metal ceramic restoration(P<0.001) in three coordinate dimensions(L, a, b). The Vita porcelain had most similar to the control group(∆E=1.58) and the ceramco2 porcelain was un match to the control group(∆E=2.65). The data of this study indicated that type of porcelain had significant effect on metal-ceramic restoration color.