Fracture resistance of roots obturated with a single expandable polymer cone

Introduction Endodontically treated teeth are considered to be more susceptible to fracture than vital teeth, therefore various obturation materials and methods have been used to reinforce them and decrease the incidence of vertical root fractures. The aim of this study was to compare root fracture resistance after filling either with smartseal system (PropointPT cone and Smart‑paste Bio sealer) or with gutta‑percha in combination with either MTA Fillapex or AH Plus sealers. Materials and methods Sixty single‑canal extracted teeth were selected. The crowns were removed and the roots were prepared with ProTaper rotary system to size F4, roots were divided into four groups according to obturation system (n = 15). Group 1: smartseal system, specimens were filled with a bioceramic sealer (Smart‑paste Bio), and F4 PropointPT. Group 2: were filled with MTA Fillapex and F4 gutta‑percha single cone. Group 3: were filled with AH Plus sealer and F4 gutta‑percha single cone. In group 4, the roots were neither shaped nor filled and served as negative control. All specimens were tested in a universal testing machine as the force at the time of fracture was recorded in Newtons. Data were analyzed using the one‑way analysis of variance. Results Roots in the negative control group and smartseal group showed significantly higher values (380.7 ± 59 N) and (347.2 ± 56 N) respectively. There was no significant difference between the MTA Fillapex/gutta‑percha and AH Plus/gutta‑percha groups (227.4 ± 43 N) and (254.4 ± 55 N), respectively. Conclusion It can be concluded that the smartseal system did improve the fracture resistance of the endodontically treated roots more than MTA Fillapex/gutta‑percha or AH Plus/gutta‑percha combinations.