Objective To evaluate the effect of repeated sintering on the color and translucency of dental lithium disilicatebased glass ceramic.Methods Thirty disc specimens (10 mm in diameter, and 1.00 mm±0.01 mm in thickness) were fabricated using an IPS e.max Press HT A2 ingot and then randomly divided into six groups (S0, S1, S2, S3, S4, and S5) (n=5). Each group was sintered 0, 1, 2, 3, 4, and 5 times individually according to the manufacturer’s recommendation. After polishing, ultrasonic cleaning, and drying, the color parameters (L*, a*, and b* values) and transmittance (τ) of all the specimens were measured using a ShadeEye NCC dental colorimeter and a TM-2 spectrophotometer, respectively. Subsequently, C*ab and ΔE were calculated. The results were statistically analyzed using SPSS 17.0 software for ANOVA and LSD.Results After repeated sintering, the L* value significantly decreased (PConclusion Repeated sintering can affect the color and translucency of the IPS e.max Press lithium disilicate-based glass ceramic, but the color difference can be clinically acceptable.
