Thermal conductivity studies of composite dental restorative materials

Thermal conductivities were determined for five commercial composite restorative materials, one composite crown and bridge cement, two cavity “bases,” and poly(methyl methacrylate). In addition, the effect on thermal conductivity of concentration and type for five resin-reinforcing fillers was investigated. Depending upon type and concentration of filler, the composites ranged in thermal conductivity from somewhat less than that for dentin to slightly over twice that value. Because of their good marginal adaptation, the thermal conductivity of composites must either be closely matched to tooth structure or a base should be used in deep restorations.