Análise estrutural e de fadiga em coroas monolíticas de dissilicato de lítio via método dos elementos finitos

Abstract

The use of monolithic lithium disilicate dental crowns is widespread in dentistry, but uncertainties remain regarding how different preparation methods influence their mechanical performance, particularly in terms of fatigue. In this study, the fatigue behavior of two main types of crown preparation was evaluated: the anatomical (ANAT) preparation, in which the cusp maintains its natural curvature, and the non-anatomical (NANAT) preparation, in which the cusp is flattened. The objective was to analyze the fatigue resistance of these crowns using real specimens reconstructed as finite element computational models. The simulations were validated and subsequently used to calculate fatigue life according to the Goodman, Soderberg, and Gerber criteria. The specimens were scanned using Micro-CT, reconstructed via the finite element method, and subjected to compression tests applying loads from 0 to 500N for validation. The models were then numerically simulated, allowing comparison with the experimental tests, calculation of principal stresses, and estimation of fatigue life according to the selected criteria. The validation showed an error of 7.7% for the ANAT model and 10.6% for the NANAT model, confirming the reliability of the simulation. For the fatigue calculations, the ANAT crown model presented safety factors of 1.75 for the Goodman and Soderberg criteria and 2.08 for Gerber, while the composite resin showed factors above 20.27. For the NANAT model, the crown presented safety factors of 1.93 and 2.28 for the same respective criteria, and the composite resin exhibited factors above 22.75. These results indicate that, for both preparation methods, the components exhibit infinite fatigue life. It is concluded that both preparation techniques are mechanically effective and do not compromise crown durability with respect to fatigue.