Evaluation of stress distribution using finite element analysis method based on microcomputer tomography data of the restoration of maxillary central incisor with two different techniques of after-traumatic enamel dentin fracture

Aim:In pediatric patients, the maxillary central incisors are the most frequently traumatized teeth in the entire tooth array. These teeth are of great importance in terms of function, phonation and aesthetics. Considering that our patients who applied to our clinic due to trauma are at a young age, the restorations to be made should be long-lasting. In this study, based on the micro-computed tomography data of the maxillary central incisor with enamel dentin fracture, two techniques, namely the bonding of the broken part by means of finite element analysis and the treatment of the tooth with direct composite restoration, stress distribution will be examined under force from two different directions using different retentive procedures to be applied to the fractured tooth. Material and Method: Avulsed left maxillary central incisor was scanned with a micro-computed tomography device. The obtained data were transferred to the computer and three-dimensional modeling was performed. In the models, an oblique fracture line was created at an angle of 45 degrees, 3 mm from the disto-incisal corner of the tooth to the mesial interface. Retentive procedures used in the reattachment method; 1) Internal dentin cavity 2) Palatinal composite laminate 3) Double palatal retentive groove. A total of six models were created, with the retentive procedures used in the composite restoration technique 1) Composite lamina veneer 2) Composite restoration after enamel beveling 3) Composite application after double palatal grooves, by using the finite element analysis method, 100 N force was applied to the restored models in two different directions, incisal and palatal, and the obtained data were examined in terms of stresses on the restoration and the tooth. Results: In all models, palatal forces produced higher stress than incisal forces on enamel and dentin. It was observed that more stress was concentrated on the buccal surface of the root than on the palatal surface in all models under all forces. The model that creates the least stress on the enamel tissue was observed in Model-1, where palatinal laminate veneer was applied after reattachment. The highest stress value in composite restorations is in Model-1, The lowest stress value was observed in Model-3. In models with direct composite restoration; No significant difference was found between the maximum amount of stress accumulated on the composite, enamel and dentin surfaces. Conclusion: According to the data obtained from the modeling, the shape of the restoration applied on the tooth, the technique used, the location of the restoration and the direction of the applied force affect the amount and distribution of stress accumulated in the tooth and restoration. However, the obtained stress analysis results are not sufficient to evaluate the clinical success of restorations. The models used need to be supported by studies with other techniques. Key Words: Reattachment technique, finite element stress analysis, direct composite