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Amir Barani, Brian R. Lawn, Mark Bush, Herzl Chai


A model for the splitting of teeth from wedge loading of molar cusps from a round indenting object is presented. The model is developed in two parts: first, a simple 2D fracture mechanics configuration with the wedged tooth simulated by a compact tension specimen; second, a full 3D numerical analysis using extended finite element modeling (XFEM) with an embedded crack. The result is an explicit equation for splitting load in terms of indenter radius and key tooth dimensions. Fracture experiments on extracted human molars loaded axially with metal spheres are used to quantify the splitting forces and thence to validate the model. The XFEM calculations enable the complex crack propagation, initially in the enamel coat and subsequently in the interior dentin, to be followed incrementally with increasing load. The fracture evolution is shown to be stable prior to failure, so that dentin toughness, not strength, is the controlling material parameter. Conditions under which the critical conditions for tooth splitting in biological and dental settings are likely to be met, however rare, are considered.
ACTA Biomaterialia


tooth splitting, molar cusps, bite force, fracture mechanics modeling


Barani, A. , Lawn, B. , Bush, M. and Chai, H. (2014), MECHANICS ANALYSIS OF MOLAR TOOTH SPLITTING, ACTA Biomaterialia (Accessed March 5, 2024)
Created December 11, 2014, Updated October 12, 2021