Effect of bleaching agents on the fluoride release and microhardness of dental materials⁴

Abstract

The use of bleaching agents has become a popular procedure for whitening teeth. Recently introduced polyacid-modified composite resins (compomers) have several favorable features, such as improved physical properties and fluoride release. Because these two materials have many possibilities to interact in the oral cavity during dental treatment, it is necessary to understand such interaction. To evaluate the effect of a bleaching agent on dental restoratives, three compomers were photopolymerized and then bleached for 1, 2, 3 and 5 days with the use of 30% hydrogen peroxide. Fluoride release, surface microhardness, and surface modifications were evaluated. It was found that the cumulative fluoride release was found to be linearly correlated to the tested periods of bleaching in all compomers. Among the tested compomers, F2000 showed the highest cumulative fluoride release. Bleached compomers became soft because of surface degradation, so the surface microhardness decreased. F2000 showed an apparent crack formation that was not observed in other compomers. The nearly linear correlation between the filler content and microhardness was found in the control samples. However, the same correlation was not observed after the compomers were stored in a bleaching agent or distilled water.

Effect of Vital Bleaching on Disintegration Tendency of Glass Ionomer Restorations

“…The same idea was discussed by Lee et al, who concluded that highly concentrated bleaching regimes induced surface degradation, softening and an increase in fluoride release and changes in the coefficient of thermal expansion of polyacid-modified resin-based composites (compomers) when those bleaching agents were continuously applied for 1-5 days. In some products, even cracks were observed on the surfaces of the specimens [21].…”

Effects of different bleaching agent concentrations on surface roughness and microhardness of esthetic restorative materials

“…11 While three bleaching sessions of 30 minutes for one week intervals did not affect the surface finish of compomers, resin-modified glass ionomer cements or glass ionomer cements. 12 Cehreli et al claimed that after treatment with 10-16% CP bleaching gels, increased surface roughness of some brands of those materials were noted, while other gels had decreased surface roughness. 13 They concluded that the effects of the gels seem to be material dependent.…”

“…15 Few literature addressed the possible alteration of the surface properties of esthetic restorative materials at different concentrations of carbamide peroxide. 8,[10][11][12][13][14]16,17 The null hypotheses of the current study was that the surface roughness and the microhardness of the selected materials would not be affected by different concentrations of carbamide peroxide of the bleaching agents. The purpose of the study was to evaluate the effect of different concentrations of carbamide peroxide on the surface roughness and microhardness of the esthetic restorative materials.…”

The effect of hydrogen peroxide concentration on metal ion release from dental amalgam

“…7,8 Reports in the dental literature have suggested that bleaching agents may have adverse effects on the physical properties of dental restorative materials. [9][10][11][12] They have also been reported to increase mercury release from dental j o u r n a l o f d e n t i s t r y 3 5 ( 2 0 0 7 ) 1 7 2 -1 7 6 amalgams. [13][14][15][16] Data from the latter studies is summarised below, with our own calculation of ion release provided in brackets to assist comparison.…”