Abstract
OBJECTIVES: This study aimed to evaluate the effects of access cavity design and activation procedures on the penetration depth and bond strength of calcium silicate-based sealers to dentin, while also distinguishing the influence of the root level as an anatomical reference point. METHODS: Sixty-six mandibular molars were randomly divided into two groups based on the access cavity design (traditional (TEC) or conservative (CEC)). The distal root canals were prepared using Reciproc files (40.06). The fluorescent calcium tracer Fluo-3 was added to the calcium silicate- based sealer CeraSeal to evaluate sealer penetration into dentinal tubules in confocal laser scanning microscopy (CLSM).Each access cavity group was further divided into three subgroups according to the sealer activation technique (Non-activation (NA), EDDY, XP-Endo Finisher (XP-F)) (n = 11). Root slices of 2.0 mm thickness (± 0.1 mm) were obtained at 3-5 mm and 8-10 mm from the root apex for CLSM to evaluate the percentage of sealer penetration. The bond strength was assessed with an Instron machine. Statistical analysis was performed using three-way ANOVA with Bonferroni correction, with the significance level set at 0.05. RESULTS: There were no significant interaction effects among the independent variables (access cavity design, activation procedures and root level) (P > 0.05); however, each variable individually showed a significant main effect on both the percentage of sealer penetration and bond strength (P < 0.001). A significant main effect of access cavity design was observed, with TECs exhibiting significantly higher values than CECs in both outcomes (P < 0.001). Similarly, the root level significantly influenced results, with greater sealer penetration and bond strength at 9 mm compared to 4 mm (P < 0.001). The activation procedure also had a significant impact (P < 0.001). Post hoc comparisons using the Bonferroni correction revealed that both EDDY and XP-F significantly improved sealer penetration and bond strength compared to no activation (NA) (P < 0.001). However, no statistically significant difference was observed between EDDY and XP-F (P > 0.05). CONCLUSION: The TEC design, the use of EDDY and XP-Endo Finisher activation techniques and the examination of coronal root levels resulted in a greater percentage in sealer penetration and higher values of bond strength. TRIAL REGISTRATIONS: Clinical Trial Number: Not applicable.