The Effect of Different Ferrule Configurations and Preparation Designs on the Fatigue Performance of Endodontically Treated Maxillary Central Incisors: A 3D Finite Element Analysis

The presence of an adequate circumferential ferrule is of great importance for the prosthetic rehabilitation of endodontically treated teeth. However, there may not be an adequate circumferential ferrule effect. This study aimed to evaluate the fatigue performance of endocrown and post–core restorations applied to different configurations without an adequate ferrule effect using the finite element method and endeavors to offer a comprehensive perspective on the challenging rehabilitation of maxillary incisors with excessive coronal substance loss, addressing a notable gap in research and providing valuable insights for clinicians. The goal is to address this gap in research and contribute valuable insights that could be beneficial for practitioners. The maxillary central incisor was selected, and lithium disilicate (LS) and a polymer-infiltrated ceramic network (PICN) were used in post–core groups with no ferrule effect (PC0); a 2 mm ferrule effect on the buccal wall (PC1); a 2 mm ferrule effect on the buccal-mesial wall (PC2); a 2 mm ferrule effect on the buccal–mesial–palatal wall (PC3); and a 2 mm circumferential ferrule effect (PC4) In the endocrown groups, an external retention group with a circumferential ferrule (ECER) and an inner retention form group (ECIR) were prepared. Fatigue performance was examined by applying a 150 N oblique load. The evaluation of the fatigue performance of the restorative materials shows that LS always had more successful fatigue performance results, while the post–core groups were generally more successful in terms of dentin survival. In situations where there is insufficient circumferential ferrule, the application of endocrowns is likely to result in a less successful prognosis for survival.