The Effect of Repeated Firings on the Color Change of Metal Based Ceramics Produced with Different Techniques

Abstract

Aim: The purpose of this study was to compare the effects of repeated firings on the color change of metal-ceramic restorations with different porcelain thicknesses and metal coping fabrication methods. Material and Methods: A total of 30 disc-shaped samples of 1 mm thickness and 13 mm diameter were produced using selective laser melting (SLM) and conventional casting (CC) methods. Feldspathic porcelain in thicknesses of 0.7, 1.2 and 1.7 mm were then applied to each group (n = 10). Each sample was subjected to five firing processes. After each repeated firing process, color measurement was performed using a spectrophotometer. One-way analysis of variance was used for the statistical analyses and Tukey’s test was used for post-hoc analyses (p = 0.05). Results: There were significant differences in color changes both groups (p < 0.05). The SLM samples underwent more color changes than the CC samples. Conclusion: As a result of the study it was determined that repeated firings and an increase in the porcelain thickness enhanced color changes. Moreover, the color of SLM samples changed more than the CC samples.