Root Canal Filling of Teeth with Open Apex Using Different Techniques, Low-Temperature Gutta-Percha Points, and Bioceramic Sealers

To evaluate the impact of different root canal filling techniques on the push-out resistance to dislodgment of the filling material to dentin, the quality of the filling interface, and root temperature variation in teeth with open apex. Forty-eight human maxillary canines with open apex were divided into 4 experimental groups, according to the technique for root canal filling: Group I - apical barrier with MTA and backfill technique, Group II - apical filling with conventional points and continuous wave technique (4mm/200ºC), Group III - apical filling with low-fusion gutta-percha points and continuous wave technique (4mm/100ºC), Group IV - conventional single cone technique. Temperature changes on the outer surface of the root were measured in thirds during the filling. BS was evaluated using the push-out test. The adhesive interface was examined using scanning electron microscopy. Analysis of variance was used to analyze BS and temperature variation data, while the chi-square test was used to analyze failure type. The fit of the filling material to the dentin wall was evaluated using non-parametric Mann-Whitney and Kruskal-Wallis tests, followed by Dunn's test. The group using the MTA barrier (4.5±3.5) showed higher BS values compared to the conventional points (2.8±1.1), low-fusion points (3.1±2.1), and the single cone technique (2.7±2.3) (p<0.05). In terms of temperature variation, a greater temperature increase was observed in the low-fusion points group (p<0.05). MTA barrier exhibited the highest BS values and adhesive interface quality, while the continuous wave condensation technique, regardless of the type of gutta-percha point used, showed intermediate values compared to the single cone technique.