Distribution of stresses in porcelain-fused-to-metal and porcelain jacket crowns.

An idealized porcelain jacket and porcelain-fused-to-metal crown model was prepared, loaded, and analyzed to establish the trends and distributions of the internal and external stresses. Loads at 30 degrees to the vertical axis created adverse tensile stresses at the level of the gingiva and specifically at the gold-dentin-cement interface.