Influence of non-carious cervical lesions, bone attachment level, and occlusal load on the stress distribution pattern in maxillary premolars: finite element analysis

ABSTRACT

This study aimed to evaluate the influence of different bone attachment levels and occlusal loads on the stress distribution pattern of maxillary premolars with or without non-carious cervical lesion (NCCL), before and after restoration with composite resin by three-dimensional (3D) finite element analysis. From the healthy model, NCCL models were produced and the cavity was restored with composite resin. Models with vertical and horizontal bone loss were also made. For each model, three types of occlusal loads were simulated (100 N) vertical load (VL), buccal load (BL), and palatal load (PL). After processing the models, the data were obtained in MPa for the criteria of Maximum Principal Stress (for all structures) and Minimum Principal Stress (for cortical and medullary bones). Stress values were collected for a node on the cervical buccal surface (Maximum Principal Stress) and the buccal crestal bone (Minimum Principal Stress). As a result, the different bone attachment levels did not affect stress distribution at the amelodentinal junction. The buccal load promoted a higher concentration of compressive stress on the buccal bone surface and the palatal load resulted in greater tensile stress in the buccal cervical third of the tooth. The concentration of tensile stress in the buccal cervical third was exacerbated by the presence of NCCL and it was similar to the healthy and restored models. It can be concluded that stress concentration at the bone level does not depend on the presence or absence of NCCL and the restoration procedure but it is related to the type of occlusal load. However, the presence of NCCL promoted a higher stress concentration in the cervical region, especially when combined with oblique occlusal loads.