Análise da resistência de união de obturações endodônticas em função de diferentes técnicas termoplastificadoras

Abstract

The success of endodontic treatment depends on a good seal of the root canals. Different filling techniques, such as the use of heated gutta-percha, have been studied to improve adaptation and sealing. This study aimed to evaluate the bond strength of fillings made with the endodontic cement AH Plus Jet using three obturation techniques: ultrasonic vertical condensation (CVU), continuous wave condensation (OC), and single cone (CON), which also served as the control. For this, thirty human upper molars were used, with the chemical-mechanical preparation of the disto-buccal roots starting with K #25 files and finishing with instruments from the Reciproc R40 and R50 system; a 2.5% sodium hypochlorite solution was used as the irrigating solution. After preparation, the teeth were randomly divided into three experimental groups (n = 10) based on the obturation technique and filled 1.0 mm short of the actual canal length. The specimens were then numbered, randomized by an external researcher, and stored in na incubator for 14 days (37°C and 100% humidity). The roots were then cross-sectioned to perform the push-out test to determine the bond strength to the dentin. The results were statistically analyzed for normality (Shapiro-Wilk), and then by analysis of variance (Kruskal-Wallis) and post-hoc comparisons (Dunn), considering a 5% significance level. The highest bond strength values were provided by the CWC (6.87 MPa) and UVC (6.47 MPa) groups, while the SC group (2.47 MPa) showed the lowest bond strength values (p<0.05). The Chi-square test did not identify significant differences in the types of failures found (p > 0.05). Under the conditions of the study and based on the results, it can be concluded that the CWC and UVC techniques provided better bond strength to dentin compared to the SC technique, suggesting that using these techniques may be more effective in ensuring superior adhesion to the dentin substrato.