RESUMEN
OBJECTIVE: To evaluate the influence of different endodontic materials on root fracture susceptibility. METHODS: Seventy-two mandibular incisors were sectioned 1mm below the cementoenamel junction to obtain roots of 12 mm length. Roots were submitted to chemomechanical preparation with the rotary instruments of Profile system. The obturation of root canals were performed with the following filling materials (n=12): GI, unfilled teeth (control); GII, Endofill+gutta-percha; GIII, Sealer 26+gutta-percha; GIV, AH Plus+gutta-percha; GV, Epiphany+gutta-percha; GVI, Epiphany+Resilon. After the sealers setting time, each root was embedded in acrylic resin. The specimens were then submitted to fracture resistance test using an Instron testing machine at 1mm/min. RESULTS: The ANOVA test showed no significant statistical difference (p>.05) among GI (162.16+/-41.4N), GII (168.46+/-37.5N), GIII (164.83+/-35.7N), GIV (168.29+/-38.7N), GV (172.36+/-20.6N) and GVI (193.11+/-42.8N). CONCLUSION: The core materials (gutta-percha or Resilon) combined with the tested endodontic sealers are not able to increase the root fracture resistance in canals submitted to chemomechanical preparation.