Evaluation of the colour and translucency parameter of conventional and Computer-aided design and computer-aided manufacturing (CAD-CAM) feldspathic porcelains after staining and laser-assisted bleaching

AIMS: The present study aimed to evaluate the color and translucency changes of the feldspathic porcelain samples made using the conventional or computer-aided design/computer-aided manufacturing (CAD/CAM) methods after immersion in staining solutions and laser bleaching. MATERIALS AND METHODS: A total of 72 samples of feldspathic porcelain were fabricated using the conventional (n = 36) or CAD/CAM (n = 36) methods. Afterward, each group was randomly divided into three subgroups (n = 12), which underwent exposure to coffee, orange juice, or distilled water for 6 weeks. Then, the samples underwent diode laser-assisted bleaching. A spectrophotometer assessed the samples’ color and translucency preintervention, after staining, and after bleaching. STATISTICAL ANALYSIS USED: One-way and two-way analysis of variance and independent t-test were used. The significance level was 0.05. RESULTS: Staining for 6 weeks significantly changed the color of both types of feldspathic porcelains. Furthermore, there were significant differences between the ceramics made using different methods and immersed in different staining solutions (P < 0.001). Furthermore, laser-assisted bleaching changed the color of immersed specimens significantly (P = 0.005). However, there were no significant translucency changes in all the subgroups after staining (P = 0.215) and laser bleaching (P = 0.325). CONCLUSIONS: The staining-induced discoloration of all the subgroups was in the clinically acceptable range (ΔΕ<3.3). In addition, bleaching could effectively remove the stains in both types of ceramics while not affecting the primary color. Moreover, the translucency of the ceramics was not affected by staining or laser-assisted bleaching.