Evaluation of the amount of apically extruded debris during retreatment of root canals filled by different obturation techniques.

OBJECTIVE: To evaluate the amount of apically extruded debris during retreatment (with or without solvent) of root canals filled by two obturation techniques. MATERIALS AND METHODS: Forty-eight root canals were prepared using ProTaper Universal F3 and filled with Gutta-percha and AH 26 sealer using single cone or lateral condensation techniques. The root canal fillings were removed using ProTaper Universal Retreatment system with or without solvent, and the canals were further prepared with ProTaper F4. The operating time was measured. The debris extruded was collected into preweighed Eppendorf tubes. The dry weight of the extruded debris was calculated by subtracting the weight of the empty tube from that of the tube containing debris. Statistical analysis was performed with two-way analysis of variance test, with Bonferroni correction at a 95% confidence level. RESULTS: There was no statistically significant difference in the amount of extruded debris between the two obturation techniques (P=0.332). The mean amount of debris was higher in the nonsolvent groups than the solvent groups, particularly with the single cone technique (P=0.013). There was a significant difference between groups with regard to the retreatment time (P<0.001). Gutta-percha removal took less time in the single cone group than in the lateral condensation group (P<0.001). Gutta-percha removal in the nonsolvent groups took significantly less time than that in the solvent groups (P<0.001). CONCLUSIONS: The amounts of apically extruded debris were similar in both obturation techniques. A greater amount of apically extruded debris was observed in the nonsolvent groups than the solvent groups.