Effects of toothbrush abrasion on color, gloss, and surface roughness, and thermal cycling on bond strength of CAD-CAM composite resin block with light-cured resin coating restoration materials.

This study aimed to evaluate the usefulness of light-cured resin coating restoration materials (RCs) on anterior composite resin blocks by quantifying the color, gloss, and surface roughness before and after toothbrush abrasion test and to evaluate the shear bond strength before and after thermal cycling test. Four types of RCs were used in the experiments. The application of RCs to composite resin blocks resulted in color changes and a decrease in gloss after the toothbrush abrasion test; however, both were within clinically acceptable limits. The surface roughness was at a value that made bacterial adhesion difficult both after the application of RCs and after the toothbrush abrasion test. The shear bond strength also had clinically acceptable bond strength. Therefore, the application of RCs to composite resins in the oral cavity is considered effective in terms of maintaining esthetics, gloss, and surface properties, as well as the durability of RCs.