Non-linear elastic three-dimensional finite element analysis on the effect of endocrown material rigidity on alveolar bone remodeling process.

OBJECTIVES In healthy conditions, modeling and remodeling collaborate to obtain a correct shape and function of bones. Loads on bones cause bone strains which generate signals that some cells can detect and respond to. Threshold ranges of such signals are genetically determined and are involved in the control of modeling and remodeling. The present study aimed at assessing the deformations transferred to surrounding bone by endodontically treated maxillary central incisors restored with endocrowns made up of high or low elastic modulus materials. METHODS The solid model consisted of a maxillary central incisor, the periodontal ligament (PDL) and the surrounding cortical and cancellous bone. Both composite and alumina endocrowns were simulated under load and compared to a sound tooth. Dynamic non-linear analyses were performed to validate discretization processes. Non-linear analyses were performed on teeth and surrounding bone to estimate strain variations according to restorative techniques. RESULTS Strain values in cortical bone, spongy bone, alveolar cortex and tooth were evaluated. PDL allowed models to homogeneously transfer loads to bone. Strains developing in highly rigid restorations were estimated to activate bone modeling and remodeling. SIGNIFICANCE The higher deformability of composites could enable restorative systems to transfer limited strains to compact and spongy bone of tooth socket. Although composites could not prevent the physiological resorption of the alveolar bone, they could successfully reduce strain arising in tooth socket when compared to alumina. The PDL prevented bone to undergo high deformations, resulting in natural flexural movements of teeth.