K Sundeep Hegde, Reshma M Suvarna, Sham S Bhat
Department of Pedodontics and Preventive Dentistry, Yenepoya Dental College, Mangalore, Karnataka, India.
Background: Children at high risk exhibiting anterior tooth decay and/or molar caries may benefit by treatment with stainless steel crowns (SSCs) to protect the remaining at-risk tooth surfaces. The nonlinear finite element analysis (FEA) has become an increasingly powerful approach to predict stress and strain within structures in a realistic situation that cannot be solved by conventional linear static models. There are very few studies that have measured the stress in endodontically treated primary teeth, especially when restored with crowns. Hence, this study is done to analyze stress in endodontically treated primary molar without and with SSC using FEA. Methodology: A three-dimensional (3D) FEA model was generated using an intact normally extracted human maxillary deciduous second molar. The tooth was subjected to a computerized tomography (CT) scan, and a cross-section of the tooth was obtained at an equal interval of 0.5 mm, in Digital Imaging and Communication in Medicine (DICOM) format. The 3D geometrical model of the tooth was converted from CT DICOM as a 3D model. Two models were created: Model 1 – without SSC; Model 2 – with SSC. They were then subjected to an occlusal load (354 N, 179 N, 42 N, and 8 N) both vertically and horizontally. Results: With increased load, there is an increase in Von Mises stress and strain. The displacement patterns are well within the safe range for Model 2 as compared to Model 1. Conclusion: Endodontically treated tooth when not suitably restored with a SSC results in fracture of the underlying tooth structure. Finite element model can not only be used to evaluate stress but can also be used as a tool to educate patients regarding the importance of postendodontic restorations.
Keywords: Deciduous molar, finite element model, Poisson’s ratio, stainless steel crown, stress analysis, Von Mises stress.