Evaluation of stress distribution in root canal treated maxillary incisors treated with different fiber-reinforced composite resins by finite element analysis

Objective: The aim of this study is to evaluate the stress caused by different fiber reinforced composite resin (FRCR) restorations under functional forces in tooth models with two different types of horizontal and oblique fractures in the maxillary incisor using finite element analysis (FEA) method. Materials and Methods: A maxillary incisor with complete root development was scanned in a microcomputed tomography device. With the information obtained, two different groups with horizontal and oblique fractures were formed by creating a maxillary incisor model with three-dimensional root development. Based on the sample model, root canal treatment was performed, horizontal and oblique fracture lines were created, maxillary incisor models were restored with different FRCR and simulated in three dimensions. Then, the stresses occurring in the teeth under functional force were evaluated with the FEA method. Results: In models using FRCR, the stresses on the cervical region of root dentin and restorative material were reduced. When all models were examined, the highest stress values in both the cervical region of root dentin and the restorative material were observed in models using only composite resin. The lowest stress values were observed in the models using prefabricated long glass fiber post. It was observed that the stresses occurring in the models with the horizontal fracture line were higher than the models with the oblique fracture line. Conclusion: The use of FGKR in teeth with crown fractures will help reduce both the stresses in the cervical region of root dentin and the stresses on the restorative material. Models restored with FGKR created less stress and strengthened the tooth structure more. Key Words: FRCR, FEM, nanofil composite, post, complicated crown fractur