Reversal of Compromised Bond Strength of Bleached Enamel Using Cranberry Extract as an Antioxidant: an In Vitro Study

Bleaching reduces the bond strength of enamel, if adhesive restorations are carried out immediately. Reversal of compromised bond strength of bleached enamel by application of antioxidant agents has been reported in the literature. The aim of the study is to assess the neutralizing effect of 6% cranberry (CB) solution on the bond strength of bleached enamel compared with that of 10% sodium ascorbate (SA) solution.

Enamel surfaces of 64 extracted human premolar teeth were randomly divided into four groups based on the antioxidant used. Further subgrouping was done in Groups II, III, and IV dividing each group into subgroup A and subgroup B of eight teeth each based on whether the bonding was performed immediately or after a delay of 14 days postbleaching respectively. Shear bond strength (SBS) of the specimens was measured using a Universal testing machine. The data were then tabulated and statistically analyzed using one-way ANOVA (analysis of variance) and Tukey's post-hoc parametric tests. A p-value of <0.05 was considered statistically significant.

The SBS measurements were compared among the four groups including the subgroups. The SBS was highest in the SA delayed bonding group and lowest in the bleached immediate bonding group.

A 10% SA solution has proven superior to 6% CB solution in the reversal of compromised bond strength following bleaching.