Effect of Two Bleaching Techniques on Teeth Discolored with Different Calcium Silicate-Based Cements

Objectives: The objective of this study was to investigate tooth discoloration caused by different calcium silicate-based cements (CSCs), and assess the efficacy of two bleaching techniques in restoring the original tooth color. Materials and Methods: In this in vitro study, 54 sound teeth were divided into three groups (n=18) of Endocem, MTA Angelus, and calcium-enriched mixture (CEM) cement. Baseline color assessments were conducted using a spectrophotometer, with subsequent color evaluation after 3 months. Each group was divided into two subgroups of internal bleaching and internal/external bleaching. The bleaching procedure was performed over a 2-week period. Two-way ANOVA was applied to investigate the interaction effect of bleaching technique and time on color change (∆E). The Tukey's test was used as post-hoc for pairwise comparisons. P≤0.05 was considered significant. Results: The results indicated noticeable color change in all test groups, surpassing the perceptibility threshold (ΔE>3.3). Endocem exhibited the maximum discoloration, while CEM cement displayed the minimum. Significant differences were observed between Endocem and other groups (P<0.05). Regarding the L*, a*, and b* parameters, no significant differences were found between the two subgroups except in Endocem group, where internal/external bleaching caused a significantly greater increase in color parameters compared to internal bleaching (P=0.001). Conclusion: Endocem induced more discoloration than MTA Angelus and CEM cement. However, there was no difference in efficacy between the internal and internal/external bleaching techniques (except in Endocem), both proving effective in restoring the original color of discolored teeth.