Fracture resistance of roots filled with gutta-percha or RealSeal®

Abstract

To evaluate the vertical root fracture resistance of maxillary central incisors filled with different root filling materials and sealers. Forty maxillary central incisor root canals were instrumented and divided randomly into four groups. Each group was filled using lateral compaction, with gutta-percha and AH Plus, gutta-percha and RealSeal(®) sealer, RealSeal(®) cone and RealSeal(®) sealer, or RealSeal(®) cone and AH Plus, respectively. The roots were loaded vertically by a conical spreader tip inserted into the canal and attached to an Instron testing machine until root fracture occurred. The load at fracture and the pattern of fracture were recorded. Mechanical properties of both core materials were tested under compressive loading. Results were analysed statistically by two-way analysis of variance and post hoc Tukey's tests. An independent sample t-test was used to compare the mechanical properties of the filling materials. Load at fracture of roots filled with gutta-percha and AH Plus (255 ± 74 N) and gutta-percha and RealSeal(®) sealer (237 ± 38 N) was significantly greater than those filled using the RealSeal(®) system (163 ± 29 N) and RealSeal(®) cone with AH Plus sealer (134 ± 17 N). Most fracture lines were in a bucco-lingual direction. In compressive tests of the core materials, RealSeal(®) had greater flow in response to load than gutta-percha, suggesting more efficient transmission of forces to the canal wall in the fracture tests. The lower fracture resistance of roots filled using RealSeal(®) is probably the result of more efficient transmission of forces within the canal, rather than a direct effect of the material itself.