Influência de lesões cervicais não cariosas e perda óssea associada com movimentos ortodônticos: análise de elementos finitos

Abstract

The objective of this study was to analyze the biomechanical effects of pre-molar NCCLs and bone loss in premolar, during orthodontic movement. Cone beam CT scan of the maxilla was used to construct of tetrahedral models of the first (14) and second premolars (15) and first molar (16), sound and periodontally healthy. Twelve models were generated from combinations of two factors: 1- crown condition of tooth 15(sound, with unrestored NCCL, with restored NCCL) 2- level of bone loss (without, ¼, ½ and ¾). Finite element analysis (FEA) was used to evaluate these combinations under extrusive (EX) and intrusive (IN) loads. EX produced greater tension than IN, in all situations and even under lighter loads. NCCLs were associated with greater tension regardless of region: marginal alveolar bone crest (MAC), crown buccal cervical region (CBC), buccal apical third of the root (BAR). Tension in the restored NCCL teeth was similar to that of the sound teeth, regardless of movement type. Bone loss strongly affected tension in all situations. It is concluded that NCCLs generate internal tension that is greatest under EX, while restored NCCLs produce internal tension that is similar to that of sound teeth and finally, greater alveolar bone loss is associated with greater tension in the root and alveolus, especially at the level of the marginal bone crest.