Abstract
Aim: The aim of this study was to compare the reversal of shear bond strength of composite to bleached enamel immediately after bleaching followed by application of various antioxidant solutions. Material and Methods: Seventy central incisors were divided into seven groups. Groups I and II served as unbleached and bleached controls respectively. Groups III, IV, V, VI and VII served as the experimental groups and were subjected to 37.5% hydrogen peroxide bleaching followed by 10 min application of 10% sodium ascorbate, 25% alpha-tocopherol, 6.5% grape seed extract, 5% lycopene and 5% green tea extract respectively. Following composite bonding, shear bond strength was determined and the results were analyzed using ANOVA followed by Post Hoc Multiple Comparisons test. Results: The bond strength values for Group I (positive control) were maximum and significantly different than all the other groups except Grape seed extract group (Group V). When compared to Group II (bleached control), all the groups showed significantly higher bond strength. Significant difference in the bond strength values were seen between Group III (10% sodium ascorbate) and Group V. Also values for Group V were significantly different from Group VI (5% lycopene). All the other values showed insignificantly different results. Conclusion: All the antioxidant solutions improved the shear bond strength values after bleaching but only Grape seed extract application reversed the values to the non bleached levels. Lycopene was least effective. Other antioxidants showed comparable results.
Mass spectrometry quantitation and analysis of urinary metabolites of grape seed extract polyphenols in a rat model of menopause (1025.11)