To Evaluate and Compare the Effect of Number of Firings on the Color Stability of All-Ceramic System Using a Spectrophotometer: An in Vitro Study

Background: Ceramic restorations have been advocated for superior esthetics, and various materials have been used to improve ceramic core strength, but there is a lack of information on how color is affected by fabrication procedures. This study was designed to compare the effect of no. of firings on color stability in all ceramic restoration. Methods and materials: Thirty-disc shaped specimens were made of 7mm diameter with 2mm thickness (All-ceramic- ivoclar IPS e�max press). Repeated firing cycles (5, 7, or 9) was performed, and associated color change was compared. Color differences among the specimens was measured using a spectrophotometer. A portable reflectance spectrophotometer is used. Values of the color change are recorded in the CIELAB color system. Data expressed in Commission Internationale de 1’Eclairage (CIE)LAB system coordinates. The CIELAB color space provides L*a*b* values for each sample. Statistical analysis of data was done to draw conclusions. Result: The L*a*b* values of all ceramic system were affected with increase number of firings (5,7,9) on veneering porcelain material. L* value non-significantly increase. For veneering porcelain, the a* value decreased after repeated firings and the b* value decreased after repeated firings. Conclusion: Too many firings give a lifeless over translucent porcelain in a clinical situation, a comparative analysis will help a clinician to choose a restoration that is best suited for a patient and which will also restore the esthetics.