Comparison of exothermic release during polymerization of four materials used to fabricate interim restorations.

Four materials commonly used to make resin crown and fixed partial denture interim restorations (poly)methylmethacrylate, vinyl ethylmethacrylate, visible-light activated resin, and a Bis-acryl composite resin) were studied to evaluate their heat-producing capabilities. All four materials, despite manufacturers' claims, created a rise in temperature during polymerization. Poly(methylmethacrylate)'s temperature increases were significantly higher than those of the other three materials and visible-light activated resin had temperature increases that were significantly lower than those of the other three products. Dentists must be aware of all potential heat-producing sources to minimize thermal injury to the hard and soft tissues of the oral cavity during the fabrication of interim crowns and fixed partial dentures.