The effect of residual root length and different root canal filling materials on biomechanical stress distribution following apical resection: a finite element analysis study

This study aimed to evaluate the effects of different root canal filling materials (RCFMs) and apical resection lengths on the biomechanical behavior and stress distribution of maxillary central incisors using finite element analysis (FEA). A model of a maxillary central incisor was developed to simulate apical resections at lengths of 1 mm, 2 mm, and 3 mm. Each resected model was filled with the following RCFMs: gutta-percha, Biodentine, or mineral trioxide aggregate (MTA). The distribution of von Mises stress and safety factor values within the dentin was evaluated through three-dimensional FEA to assess the biomechanical performance under simulated loading conditions. Biodentine-filled models showed the lowest von Mises stress values (76.9–80.7 MPa). These were followed closely by the models filled with MTA (Models 7–12), which had stress values between 76.999 and 80.722 MPa. Gutta-percha models combined with MTA or Biodentine resulted in higher stress values. Both the choice of RCFM and the level of apical resection affected the pattern and values of stress distribution observed in the resected teeth. Biodentine and MTA exhibited lower stress distribution compared to gutta-percha. These findings suggest that bioactive materials may enhance the long-term stability of teeth undergoing apical surgery.