In dentistry, the finite element method has been used for clarifying the cause of tooth fracture and for designing a prosthetic appliance through stress analysis generated in the tooth and the prosthetic appliance. In previous reports, theoretical occlusal contact and average occlusal force were used in stress analysis. However, a 3D finite element model (3D-FE model) reproduced with specific occlusal contacts, occlusal force and dental morphology was necessary in order to diagnosis tooth condition and select appropriate prosthetic appliance for patients. The purpose of this study was to develop the 3D-FE model reproduced with occlusal contacts, occlusal force and dental morphology, and to validate accuracy.
Methods:
Subjects were dental casts replicated from dental study models. Occlusal contacts were extracted from a transmitted image of the inter-occlusal record. Occlusal force was measured by T-Scan. The 3D model of dentition was generated via a 3D scanner. Occlusal contacts were aligned with the contact position of the T-Scan by simultaneously acquiring the inter-occlusal record and T-Scan. Then, the occlusal contacts were projected on the 3D model of dentition, and the 3D-FE model was generated. Accuracy was verified by comparing the occlusal contact of the 3D-FE model and the 3D model of the inter-occlusal record. The evaluation region was the upper left first molar. The evaluation items were the occlusal contact area, the distance between centroids and the occlusal contact area overlap.
Results:
Occlusal contacts and force could be reproduced with the dental morphology. The mean occlusal contact area difference was 0.41±0.82 mm2, the mean distance between centroids was 0.20±0.09 mm and the mean occlusal contact area overlap was 79.4±8.61%.
Conclusions:
Through this study, a 3D-FE model recreated with occlusal contacts, occlusal force and dental morphology could be developed. The accuracy of the patient specific 3D-FE model for verification was favorable.