Influence of conservative endodontic access and the osteoporotic bone on the restoration material adhesive behavior through finite element analysis.

Assess, using finite element analysis, the adhesive behavior of Class I restorations under physiological occlusal loads on an endodontically treated first upper premolar with conventional and conservative crown opening surrounded by alveolar bone in normal and osteoporotic conditions. For this, four virtual models were used: M1-conservative access/normal bone; M2-conventional access/normal bone; M3-conservative access/osteoporotic bone; M4-conventional access/osteoporotic bone. On enamel, under axial load, the highest peaks occurred on conventional models and, under oblique load, the highest peaks occurred on conservative opening models. The bone condition showed no influence on the adhesive behavior. On dentin, under axial load, the models showed similar behaviors, regardless of the bone condition; under oblique load, the highest incidence of forces occurred on the distal region of the palatal root canal entrance and the highest peak was observed in the conventional opening model with normal bone. Also, under oblique load, conventional opening models showed larger values on dentin for the normal bone and similar for the osteoporotic. The conclusions shows higher displacement tensile strength peaks were observed in the conventional models, which can lead to a greater risk of adhesive failure on class I restorations with this opening. Therefore, a conservative opening would be recommended to avoid opening clinical complications. The bone condition showed no significant influence on adhesive behavior, except for dentin under oblique load, where conventional models showed larger values relative to normal bone and similar to the osteoporotic bone.