Asymptotic analysis of the stress field in adhering dental restorations

Polymer-based composites are widely used in restorative dentistry as altern atives to metals and ceramics to fill cavities in teeth. They adhere to the walls of the cavity in the tooth, thus forming a composite body consisting of dentine, enamel, ann composite resin. Geometric discontinuities along t he interfaces between these materials can induce singularities in the stres s field, which in turn lead to premature failure of the restoration. In the present investigation, a complex stress function technique is employed ro derive the order of the stress singularity. It is shown that the order of t he singularity depends on both the material properties of the restorative m aterial and the local geometry of the cavity. It is also shown that the sin gularity in the stress field can be avoided through careful design of the c avity shape. The results presented correlate well with experimental results reported in the literature. [S0148-0731(00)01504-1].