fracture resistance of immature teeth filled with mineral trioxide aggregate or calcium-enriched mixture cement: an ex vivo study

background: the ability of mineral trioxide aggregate (mta) to strengthen the tooth structure has been studied with contradictory results, and there is a lack of data in the case of calciumenriched mixture (cem) cement as a novel endodontic biomaterial. the aim of the present study was 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 maxillary incisors. access cavities were prepared. five teeth were randomly selected as negative control. the root length of the remaining teeth was standardized to 9 mm. rotary files and peeso reamers were used 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 mta or cem cement, respectively. in group 3, a 5-mm mta plug was placed, and the remainder of the canal was filled with composite resin. the canals of the positive control were kept unfilled. after 6 months, the teeth were tested for fracture strength in a universal testing machine. the groups were compared using univariate analysis of variance (anova). results: there were significant differences between fracture strength of experimental groups with that of both control groups (p<0.05). however, the differences among the three experimental groups 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