Abstract
AIM: The aim of this study was to assess the influence of three types of intraorifice barriers (IOBs) on the fracture toughness of root canal-treated teeth subjected to intracoronal bleaching. MATERIALS AND METHODS: Endodontic therapy was performed on 60 extracted maxillary central incisors, which were subsequently randomized into four groups (n = 15): Group I - glass-ionomer cement, Group II - TheraCal, Group III - Ionoseal, and Group IV - control (no barrier). Following placement of the designated IOB materials, intracoronal bleaching was performed using 35% hydrogen peroxide. The fracture toughness of all specimens was evaluated using a universal testing machine. STATISTICAL ANALYSIS: A statistical evaluation of the data was carried out with one-way analysis of variance and subsequent post hoc analysis. RESULTS: All the IOB groups showed higher fracture toughness than the control group. Among the tested materials, TheraCal exhibited the highest reinforcement, followed by Ionoseal and GIC, with statistically significant differences (P < 0.05). CONCLUSION: Endodontically treated teeth subjected to intracoronal bleaching demonstrated greater fracture resistance when IOBs were applied. TheraCal proved to be the most effective material, highlighting its clinical relevance in preserving tooth integrity during bleaching procedures.