Setting stress in composite resin in relation to configuration of the restoration.

The setting stress in composite resins was studied as a function of restoration shape. The shape is described by the configuration factor, C, the ratio of the restoration's bonded to unbonded (free) surfaces. In an experimental set-up, the shape of the restoration was simulated by cylindrical forms of various dimensions.

The competition between the composite-dentin bond strength and the polymerization contraction stress.

The influence of contraction stresses, developed during the polymerization of composites, on adhesion to dentin treated with a dentin adhesive was studied for a chemically- and a light-activated microfilled composite. In both linear and 3-D models. The linear model consisted of an arrangement set up in a tensilometer in which the composites could be applied to a flat dentin surface fixed to the stationary cross-head at one end, and mechanically clamped to the cross-head connected to the load cell at the other end.