Occlusal loads effects on the maxillary first premolar - FEM study

Occlusal forces cause the flexion of the cusps creating tensions in the dental structure. Some authors relate the loss of dental structure on the cervical area of teeth to these tensions. Objectives:Evaluate the effect of occlusal loads on the cervical area of the maxillary first premolar using the Finit Element Method (FEM).Methods: The image of a bucco-lingual section of the selected tooth was scanned and with the aim of the ANSYS software - 5.5 version it was possible to realize the study, simulating axial and e horizontal occlusal loads. The two-dimensional model was composed of 11.012 elements and 11.096 nodes. The study had 3 steps, and the occlusal load was standardized to be 170 N. At the first step, the axial load was divided into the two contacts located on the occlusal surface simulating the mesial fossa contact, and for the two subsequent steps, horizontal loads were applied in the facial direction, to the buccal cusp (B) of the tooth, and in the palatal direction, to the lingual cusp (L).Results: The computerized data were based on VON MISES, MAXIMUM STRESS and MINIMUM STRESS analysis. The images obtained from the 3 steps of the study were printed and analysed, showing values of stress that ranged from 0 to 725,513 MPa. Conclusions: The FEM made it possible to analyze the qualitative and quantitative stress distribution in the modeled structures. The results showed that the horizontal load applied to the lingual cusp (P) created the greatest concentration of tension stress in the enamel structure. These values ranged between 362,757 MPa and 725,513 MPa, and this tension stress was located in the enamel structure, at the buccal cervical area of the tooth, close to the cemento-enamel junction.