Influence of Different Root Canal-Filling Materials on the Mechanical Properties of Filled Roots: an in vitro study

The aim of this studywas to analyze two filling materials (Resilon and Thermafil) and to evaluate their contribution to fracture resistance of endodontically treated teeth. Thirty-two single rooted teeth stored in saline solution at 4°C were used on this study. The teeth were randomly assigned into four groups: Group 1 (n=10), obturation with Thermafil; Group 2 (n= 8), obturation with RealSeal 1™; Group 3 (n= 7), instrumented but not filled (positive control); Group 4 (n=7), specimens not instrumented and not obturated (negative control). The teeth were embedded in self-curing acrylic resin using a robot and the resistance to fracture was evaluated using a universal testing machine (Autograph). Statistical analysis was performed to determine significance differences (a = 0.05). Results: The present study showed that none of the rooth canal filling material could increase to fracture resistance of endodontically treated teeth. According to a Kruskal-Wallis test, there were statistically significant differences (α= 0.05), regarding the type of fracture (p= 0.031). There were more oblique fractures in the negative control group and more vertical fractures in the positive control group. Regarding the direction of the fracture, there are no statistically significant differences between the groups (p= 0,125, Kruskall-Wallis). Within the limitations of an in vitro study, it might be concluded that neither Thermafil® nor Real Seal-1® enhanced the resistance to root fracture of endodontically treated teeth.