Colour-stability and gloss-retention of silorane and dimethacrylate composites with accelerated aging

Objectives: To evaluate the colour-stability and gloss-retention of silorane versus dimethacrylate composites exposed to accelerated aging from daylight radiation. Methods: Five disc-shaped specimens of photo-cured resin-composites were prepared and manually polished for each material (Filtek Silorane, Herculite XRV, Tetric Evoceram and QuiXfil). Colour and gloss were evaluated before and after periods (baseline, 24, 72, 120 and 192 h) of accelerated photo-aging in xenon light following ISO 7491:2000. Colour measurements were performed with a colourimeter according to the CIE-Lab colour-space. The colour change (ΔE) for each time was calculated. The surface gloss was measured using a glossmeter. Results were evaluated using one-way ANOVA and Tukey tests (α = 0.05). Correlations between log time, ΔE and gloss were evaluated using Pearson's correlation (α = 0.05). Results: Materials generally decreased in L* and a* and increased in b*. The strong exception was Filtek Silorane which maintained a* and b*. ΔE was found to be a positive linear function of log time for all materials. Materials varied in the magnitude and rate of increase of ΔE with log time: QuiXfil > Tetric EvoCeram > (Filtek Silorane ≥ Herculite XRV). ΔE remained <3.3 for Filtek Silorane and Herculite XRV. Gloss was found to be a negative linear function of log time. Gloss was maximal in the sequence: Filtek Silorane ≈ Tetric EvoCeram > Herculite XRV > QuiXfil. Conclusions: Silorane gave the best overall performance in stability over time, compared to a set of representative dimethacrylate composites. © 2008 Elsevier Ltd. All rights reserved.