Modelagem computacional do contato oclusal: análise paramétrica do desgaste de superfície rugosa sob carregamento cíclico

Abstract

Human tooth wear, often caused by bruxism, can be aggravated by excessive occlusal contact. In this scenario, computational modeling plays an important role in providing a more comprehensive understanding of dental interactions. The approach used in this work to simulate the contact between rough surfaces consists of discretizing them into several intervals, so that each one represents a main roughness. Each of the asperities was subjected to a vertical displacement of a rigid plane, thus generating the contact. The deformations of the main asperities were analyzed and with homogenization techniques it was possible to develop the relationship between the responses that occurred on a microscale and the expected responses on a macroscale. Among the parameters that characterize the topography of tooth enamel, mean roughness, mean squared roughness, mean curvature, skewness and kurtosis were analyzed. Numerical surfaces were generated within the ranges of values found in the literature for the parameters. To analyze the surface hardness two methodologies were used. The first consists of indenting the rigid plane only once in each of the main asperities. In the second approach, each asperity undergoes a cyclic displacement of the rigid plane until the mesh elements reach the stress limit, resulting in plastic deformations and the appearance of cracks on the tooth enamel surface. This process can lead to the detachment of material from the surface, thus causing tooth wear. In both methodologies, it was verified that the average curvature of the asperities exerts the greatest influence on the results obtained for the surface hardness. To quantify surface wear, the volume of material detached from the surface was calculated. For this last analysis, it was found that the average curvature of the asperities is inversely proportional to wear, as lower values of this parameter resulted in greater removal of enamel from the surface. On this last approach, preliminary results on the depth of the cracks and the worn volume were found, so that the computational model can be considered coherent.