Mechanical stress generated by orthodontic forces on apical root cementum: a finite element model.

Mechanical stress generated by orthodontic forces on apical root cementum: a finite element model.
2004 May
Shaw AM, Sameshima GT, Vu HV.
PubMed
OBJECTIVES: 1) To determine the mechanical stress generated at the root apex during different types of tooth movement using a finite element model of an ideal, human maxillary central incisor. 2) To determine the relationship of thickness of cementum and the magnitude of mechanical stress at the root apex. DESIGN: Computer simulation. SETTING AND SAMPLE POPULATION: Not applicable, computer simulation. EXPERIMENTAL VARIABLES: Tooth and investing tissue layers (enamel, dentin, cementum, pulp, periodontal ligament, and alveolar bone). OUTCOME MEASURE: Von Mises and maximum principal stresses. RESULTS: Increasing the apical thickness of cementum increases the amount of mechanical stress. CONCLUSION: A finite element model incorporating all layers of a human maxillary central incisor has been developed. This model was used to determine the location and magnitude of mechanical stress generated for all regions of the tooth, PDL, and enclosed alveolar bone, when orthodontic forces are applied to the tooth. Mechanical stresses were found to increase at the root apex with increasing thickness of apical cementum.