Surface degradation of composite resins for direct restorations: effects on wear and gloss retention

The purpose of this in vitro study was to compare the 2-body wear resistance of 7 direct composite resin materials (Synergy, Filtek Supreme XTE, GrandioSO, Tetric EvoCeram, G-ænial Anterior, Venus Pearl, and Ceram.X Duo) following thermomechanical loading as well as their gloss stability following toothbrushing. For measurement of resistance to wear, 8 specimens of each material were thermomechanically challenged under 200,000 load cycles at a maximum force of 49 N and 500 thermal cycles between 5°C and 50°C simultaneously. Wear was analyzed by measuring the volume and vertical loss of the contact point area using a high-speed 3-dimensional scan. For gloss measurements, 8 additional specimens of each material were evaluated using a glossmeter after being subjected to 15 minutes of brushing with an electric toothbrush at a 200-N application force. Filtek Supreme XTE had the least volumetric wear, while G-ænial Anterior and Ceram.X Duo had the greatest. The greatest vertical loss was recorded for G-ænial Anterior and Ceram.X Duo. Ceram.X Duo also had the greatest loss of gloss units, together with Venus Pearl. The universal composite Filtek Supreme XTE demonstrated the lowest wear rates and the best gloss retention.