The effect of varying thicknesses of mineral trioxide aggregate (MTA) and Biodentine as apical plugs on the fracture resistance of teeth with simulated open apices: a comparative in vitro study

This study evaluates the fracture resistance of apical plugs created from Biodentine and mineral trioxide aggregate (MTA) in thicknesses of 3 and 5 mm within simulated open apex tooth models. Fifty human maxillary central incisors were obtained from a pool of freshly extracted teeth. In order to replicate open apices without cavity preparation, ten teeth in the control group received apical-to-coronal preparation with Peeso reamers. The remaining 40 teeth were randomly assigned to four experimental groups and received either 3 or 5 mm Biodentine or MTA apical plugs. The mean fracture loads observed in this study were as follows: control group, 431.48 N (±34.55); 3 mm MTA, 774.88 N (±62.74); 5 mm MTA, 752.65 N (±73.79); 3 mm Biodentine, 918.25 N (±59.09); and 5 mm Biodentine, 903.42 N (±24.48). Specifically, teeth in the Biodentine group demonstrated considerably stronger fracture resistance compared to those in the MTA group ( < 0.001). However, no significant differences were observed between the 3 and 5 mm thicknesses (MTA: = 0.98, Biodentine: = 0.99), suggesting that plug thickness did not affect fracture resistance within both groups. Biodentine apical plugs provided the highest fracture resistance among the materials, regardless of thickness.