Numerical Three-dimensional Finite Element Modeling of Cavity Shape and Optimal Material Selection by Analysis of Stress Distribution on Class V Cavities of Mandibular Premolars.

AIM: Adhesive restoration does not depend primarily on the configuration of the shape of the cavity. Under varying loading conditions, it is essential to know the stress concentration and load transfer mechanism for distinct cavity shapes. The aim of this study was to evaluate and compare the biomechanical characteristics of various cavity shapes, namely oval, elliptical, trapezoidal, and rectangular shapes of class V cavities on mandibular premolars restored with amalgam, glass ionomer cement, and Cention N using three-dimensional (3D) finite element analysis. MATERIALS AND METHODS: A 3D prototype of a mandibular premolar was generated by Digital Imaging and Communications in Medicine (DICOM) images obtained from the cone beam computed tomography and imported to 3D modeling software tool, SpaceClaim. The four distinct load magnitudes of 100, 150, 200, and 250N were applied as a pressure load perpendicular to the lingual plane of the lingual cusp of the occlusal surface (normal load) and at 45° to same (oblique load). The stress distribution patterns and the maximum von Mises stresses were analyzed and compared. RESULTS: The occlusal stresses were distributed from the force loading point in an approximate actinomorphic pattern, and when the force load was close to the margin, the stress was much greater. CONCLUSION: Ovoid cavity showed lesser stress concentration and deformation for each of the tested restorative material.

Evaluation and Comparison of Stress Distribution in Restored Cervical Lesions of Mandibular Premolars: Three-dimensional Finite Element Analysis.

OBJECTIVES: Restorative materials are used in the treatment of cervical lesions and restoration of the dental tooth. The objective of this study was to assess the suitability of the three commonly used restorative materials by dentists and the evaluation of stress distribution and deformation using Von Mises stress in cervical lesions of mandibular premolars under varying loading condition. MATERIALS AND METHODS: A computerized model of restored class V cavity of mandibular premolar tooth was created using three dimensional modeling software SpaceClaim. It was subjected to occlusal pressure load of 100, 150, 200 and 250MPa at right angle to buccal cusp and was analyzed for stress distribution and deformation in different restorative materials using Finite Element analysis, ANSYS Workbench. RESULTS: The analysis carried on the class V restored tooth from biomechanical point of view indicates that restorative material glass-ionomer cement exhibited better bonding with the tooth structure using ionic bonds with the calcium ion present in the tooth structure. The variation of 8%-9% of stress concentration is observed in cavity region across varied pressure loads with glass-ionomer cement to Cention N. CONCLUSION: Glass-ionomer cement had showed better results than amalgam in terms of biomechanical property which is in agreement with the clinical findings. The stress values of Cention N were comparable to that of glass-ionomer cement.