Colour-stability and gloss-retention of silorane and dimethacrylate composites with accelerated aging.
OBJECTIVE
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 (DeltaE) for each time was calculated. The surface gloss was measured using a glossmeter. Results were evaluated using one-way ANOVA and Tukey tests (alpha=0.05). Correlations between logtime, DeltaE and gloss were evaluated using Pearson's correlation (alpha=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. DeltaE was found to be a positive linear function of logtime for all materials. Materials varied in the magnitude and rate of increase of DeltaE with logtime: QuiXfil>Tetric EvoCeram>(Filtek Silorane>or=Herculite XRV). DeltaE remained<3.3 for Filtek Silorane and Herculite XRV. Gloss was found to be a negative linear function of logtime. Gloss was maximal in the sequence: Filtek Silorane approximately Tetric EvoCeram>Herculite XRV>QuiXfil.


CONCLUSIONS
Silorane gave the best overall performance in stability over time, compared to a set of representative dimethacrylate composites.
Furuse
Adilson Y
AY
Biomaterials Science Research Group, School of Dentistry, The University of Manchester, Manchester, United Kingdom. furuseay@yahoo.com.br
Gordon
Kathryn
K
Rodrigues
Flávia P
FP
Silikas
Nick
N
Watts
David C
DC
D000704:Analysis of Variance; D003124:Colorimetry; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects*; D008027:Light; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects*; D017797:Prosthesis Coloring; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D062047:Silorane Resins; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C510379:QuiXfil; D019279:Resin Cements; D062047:Silorane Resins; C501891:Tetric EvoCeram; C065770:Herculite XR