Evaluation of thermal conductivity and esthetic quality of denture base resin composites with acrylic polymer and nanodiamonds

The effect on the thermal conductivity and esthetic quality of acrylic denture base resins due to the addition of surface-carboxylated nanodiamonds (NDs) was evaluated using direct heat flux measurement and spectrophotometric measurement, respectively. The addition of NDs to the denture resin improved its thermal conductivity, which was highly depended on the ND content. The thermal conductivity increased significantly upon the addition of a small amount of NDs, followed by a gradual decrease with increasing ND content. The influence of the ND content on the thermal conductivity of the ND-impregnated resins was explained via experimental results and the theory of phonon scattering. Furthermore, changes in the appearance of the denture base resins caused by ND impregnation were observed to assess their esthetic qualities. The color changes in the resins with low ND contents were found to be minor. Therefore, the improved thermal conductivity and the retention of appearance of the resin can be simultaneously achieved by the addition of a small amount of NDs.