Isfahan University of Medical SciencesDental Research Journal1735-33279320120821Fracture resistance of immature teeth filled with mineral trioxide aggregate or calcium-enriched mixture cement: An ex vivo study10881088ENAminSalem MilaniDental and Periodontal Disease Research Center, Department of Operative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. amin.salemmilani@gmail.comSaeedRahimiZahraBornaMohammadAsghari JafarabadiMahmoudBahariAlirezaSighari Deljavan20120821Background: The ability of mineral trioxide aggregate (MTA) to strengthen the tooth structurehas been studied with contradictory results, and there is a lack of data in the case of Calciumenrichedmixture (CEM) cement as a novel endodontic biomaterial. The aim of the present studywas to evaluate the reinforcing effect of MTA and CEM cement on simulated immature teeth.Materials and Methods: This ex vivo study was carried out on a total of 46 human maxillaryincisors. Access cavities were prepared. Five teeth were randomly selected as negative control. Theroot length of the remaining teeth was standardized to 9 mm. Rotary files and peeso reamers wereused to enlarge the canals. The prepared specimens were randomly assigned into three experimental(n = 12) and a positive control (n = 5) groups. In groups 1 and 2, the canals were filled with MTAor CEM cement, respectively. In group 3, a 5-mm MTA plug was placed, and the remainder of thecanal was filled with composite resin. The canals of the positive control were kept unfilled. After6 months, the teeth were tested for fracture strength in a universal testing machine. The groupswere compared using Univariate analysis of variance (ANOVA).Results: There were significant differences between fracture strength of experimental groupswith that of both control groups (P<0.05). However, the differences among the three experimentalgroups were not statistically significant (P>0.05).Conclusion: After 6 months, MTA and CEM cement exhibit distinct reinforcing effect on immature teeth.Key Words: Calcium-enriched mixture cement, fracture resistance, fracture strength,immature teeth, mineral trioxide aggregate