RESUMO
Objective: In the present study, the 3D finite element method was used to investigate the effect of crown material on stress distribution in the bone surrounding immediately loaded single dental
Materials and Methods: A 3D Finite Element model of mandibular first premolar was constructed to evaluate the performance of seven crown materials with different degree of stiffness [Porcelain, zirconium, Porcelain fused to gold, pure titanium, titanium alloy, Poly methyl methacrylate, and Polyether ether ketone PEEK]. The model was constructed using Solid Works version 2010 software. The model simulated also a cement layer between the implant abutment and the crown [Virolink II, Vivadent]. An axial static occlusal force of 200 N was applied to eight points in each functional cusp. The three-dimensional [3D] FE model was analyzed by ABAQUS/CAE version 6.10 software
Results: The results of this study indicated that among all crown materials the maximum von Mises stress values was observed in porcelain crown design [345.390 MPa].The highest von Mises stresses were found in the abutments for all models. In implants, the greatest stress was concentrated on the cervical region. PMMA and PEEK crown designs transferred less stress to abutment and screw. In all models, von Mises stresses increased in the coronal third of cortical bone in which the maximum von Mises stresses observed in the implant cortical interface
Conclusions: Using more rigid material for the superstructure of an implant supports prosthesis did not have any effect on the stress values and stress distribution at the bone tissue surrounding implant. However, in the abutment, cement and crown structure, stress distributions and localizations were affected by the material's rigidity. More clinical studies are needed to evaluate the survival rate of these materials