Surface roughness and gloss retention of bioactive resin composite after simulated toothbrush abrasion

Abstract

Background. Newly introduced bioactive resin composites are being used more often. Few studies have evaluated the influence of toothbrush abrasion on their surface characteristics. Methods. This study aims to assess the surface roughness (Ra) and gloss values (GU) of 3 bioactive composites and a conventional nanohybrid composite before and after simulated toothbrush abrasion. Five samples each of Filtek Z250 XT, Beautifil Flow Plus, Activa Presto and Predicta Bioactive Bulk were subjected to 10,000 cycles of simulated toothbrush abrasion. Ra and GU values were evaluated at baseline and after each 2,500 cycles. Results. Significant difference was found in both Ra and GU (P < 0.001). For each material, GU gradually decreased as the brushing cycles increased. GU values of Beautifil Flow Plus were significantly higher at the baseline, 2,500- and 5,000-cycles stages (P < 0.05). The GU values were 78.20 (7.20), 69.67 (6.17) and 63.30 (5.52) respectively. Activa Presto showed the lowest mean GU after 10,000 cycles. A significant increase in Ra at each of the measuring stages was observed in all materials compared to the baseline measurement (P < 0.001). No significant difference in Ra values of all four materials at the baseline and up to 5,000-cycles (P > 0.05). After 7,500 cycles, the mean Ra value of Activa Presto at 0.64 (0.14) was significantly higher than that of Z250 XT at 0.49 (0.03) (P < 0.001). At 10,000 cycles, Activa Presto had significantly higher Ra at 0.70 (0.10) when compared to Z250 XT at 0.52 (0.08), Beautifil Flow Plus at 0.56 (0.07) and Predicta Bioactive Bulk at 0.59 (0.10) (P < 0.001). Conclusion. All materials showed an increase in Ra and decrease in GU after simulated toothbrushing.