Estudo da deformação e resistência de biomateriais usados para a elaboração de restaurações indiretas

Abstract

Introduction: The values of the forces exerted on occlusal areas of the teeth have high variations. The finite element analysis is a computerized technique that allows the determination of stress and/or deformation caused by the action of external forces, as well as other phenomena. Ceramic restorations produced by CAD-CAM system have just a few randomized clinical trials that demonstrated clinical success of these restorations. Objectives: To analyse the values of the forces present in human molars according to the literature; To study the stress distribution, deformation and the resistance of indirect restoration materials, in the presence of static loads by finite element method. Materials and Methods: Three crowns with a variation between the cervical region and the dental equator of 0,3 mm, 1,5 mm and 2,4 mm were scanned by cone beam computed tomography and subsequently processed by MeshLab and Autodesk® Inventor 3D CAD. Then the crowns were analysed using the finite element method by Autodesk Simulation Mechanical, considering distinct indirect restoration materials. Results: The forces mean values for maximum intercuspation were 523,938 Newton and 74,033 Newton for chewing. Inverse relationships were observed between the value of the stress / deformation of von Mises and the distance to the site of application of the force and between the von Mises deformations and the moduli of elasticity of different materials. Dental crest compared to the dental fossa presented higher von Mises stresses and deformations. The stresses/deformations did not show a linear increase with the increasing mesiodistal size of the crowns. Tensions showed in the study were lower than the flexural strength/yield strength reported by manufacturers. Conclusion: All materials have similar stresses, but they have distinct resistance to bending/yield point. According to the characteristics of the patient, the dentist should select the indirect restorative material to ensure the success of oral rehabilitation.

Date of Award	9 Dec 2016
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Helder José Martins Esteves (Supervisor) & Serafim Paulo Melo de Oliveira (Co-Supervisor)