A comparison of 2D and 3D finite element analysis of a restored tooth.

The finite element method is widely used in dental research. The decision to use two-dimensional (2D) or three-dimensional (3D) modelling is dependent on many interrelated factors. The purpose of the present study was to compare and contrast 2D and 3D finite element analysis (FEA) in investigating the mechanical behaviour of a maxillary premolar restored with a full crown under similar conditions of axial and lateral occlusal loading. The 2D analysis required modelling both a buccolingual and mesiodistal section of the restored premolar and for comparison sections of a 3D model were examined. Differences in the results for displacement and maximum principal stress distribution within the component structures and interfaces of the 2D and 3D models were, in general, attributable to differences in geometry represented in the models. Maximum principal stresses tended to be greater under lateral rather than axial occlusal loading. It was concluded that 2D FEA may find application in investigating key aspects of the mechanical behaviour of a dental restoration in a single tooth unit, but that in certain situations combinations of 2D and 3D FEA may offer the best understanding of the biomechanical behaviour of complex dental structures. Sophisticated FE models are required to better understand the mechanical behaviour of restored tooth units.