Influence of core thickness on a restored crown of a first premolar using finite element analysis.

PURPOSE This study examined the influence of ceramic coping thickness on the maximum stresses that arise in a first premolar all-ceramic crown. MATERIALS AND METHODS Axisymmetric finite element models with different In-Ceram Alumina coping thicknesses (0.3, 0.6, and 0.9 mm) were examined. Models with and without resin lute were constructed. To all models, an identical axial load of 600 N was applied vertically downward, over an area around the crown's fissure. RESULTS The resulting peak tensile maximum principal stresses in each part of the crown existed below the fracture strengths of the respective materials making up the crown. This was true for all variations of core thickness, with and without resin lute. The peak tensile stresses in the coping, porcelain, and dentin decreased for an increase in core thickness. This was most evident in the porcelain and coping. CONCLUSION The thickness of the ceramic core has a significant influence on the resulting stresses in the coping, porcelain, and dentin of this axially loaded crown.