Effect of two different bleaching regimens on the gloss of tooth colored restorative materials

Objectives: Vital tooth bleaching with peroxide is one of the most common cosmetic procedures in dentistry and can be accomplished using a variety of methods or regimens. Recently, new generation of tooth color restorative materials were introduced to market. The purpose of this in vitro study was to determine the gloss changes of three different tooth color restorative materials: Flowable composite (Filtek Flow/3 M), packable composite (Filtek P60/3 M) and ormocer (Definite/DEGUSSA) after two different bleaching regimens (Vivastyte/VIVADENT) and (Crest Professional Whitestrips/PROCTER and GAMBLE).Methods: 16 specimens 30X30x2 mm size were fabricated from each restorative material. After gloss values were measured with gloss meter, at two different angles of illumination (20 and 60%), 10% carbamide peroxide (Vivastyle) was applied for 2 h per day for fourteen days to the half of the specimens while 6.5% hydrogen peroxide strip bands (Crest Professional Whitestrips) were applied to the remaining eight of the specimens for 30 min twice daily for 14 days. During the test period the specimens were stored in 37 degrees C and 100% relative humidity. At the end of bleaching regimen the gloss measurements were repeated and the data were subjected to statistical analysis.Results: The Wilcoxon Signed Rank Test analysis revealed that the gloss values were affected by both bleaching regimens (P=0.012). Whitestrips decreased the gloss values of Filtek P60 (at 20 and 60 degrees, P < 0.001) and Filtek Flow (at 20 degrees, P=0.05 and at 60 degrees, P=0.05) significantly compared to Vivastyle, while the gloss values of Definite did not show any significant change between Vivastyle and Whitestrips application (at 20 degrees P=0.279; at 60 degrees, P=0.279, Mann-Whitney U Test). The gloss values of materials were significantly different before (at 20 degrees P < 0.001; at 60 degrees, P=0.003) and after bleaching (at 20 degrees P < 0.05; at 60 degrees, P < 0.05) with the highest value of Filtek Flow followed Filtek P60 and then by Definite (Kruskal Wallis test).Significance: As the gloss of tooth colored restorative materials could be affected by bleaching regimens, it is necessary to consider the type of the material before starting the treatment. (c) 2004 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.