Objective To compare the fracture resistance of roots filled with three different root canal filling tech-niques.Methods Forty extracted single-rooted permanent teeth were instrumented and randomly divided into four groups. Three experimental groups were filled with lateral compaction technique, vertical compaction technique and single-cone technique, respectively. No filling was performed in control group. All specimens were subjected to a vertical load to cause vertical root fracture. The force required to fracture was measured and the fracture lines was classified.Results Three experimental groups exhibited higher mean fracture load values than that of control group (179.93 N±34.03 N). There was no significant difference among the three experimental groups, and the mean fracture load values were (210.04±64.57), (232.55±50.74), (216.80±78.03) N, respectively. Eighty-five percent of root frac-ture lines were found in the bucco-lingual direction.Conclusion Root canal filling alone can’t influence the root strength significantly. There is no difference in root strength after three canal filling techniques.
