Discoloration of teeth is a common concern among patients seeking
cosmetic treatment. The color of teeth can be affected by various factors, both internal
and external, such as ingestion of chemicals or consumption of foods that can cause
staining. Currently, there are numerous products available in the market that claim to
remove stains and whiten teeth. These options include professional prophylaxis,
bleaching gels applied to vital teeth for home use, or supervised application in a dental
office. Bleaching gels typically contain varying concentrations of carbamide or
hydrogen peroxide and are applied using different methods, resulting in different
activation mechanisms that promote tooth bleaching through oxi-reduction reactions.
Unfortunately, bleaching agents have an adverse effect on bonding to enamel. This is
because of the free radicals generated by the breakdown of hydrogen peroxidecontaining bleaching agents. The free radicals hinder the resin infiltration in the interprismatic spaces, inhibit resin polymerization , and restrict resin tag creation. These
free radicals are eliminated from the body within a span of 24 hours to 3 weeks, and the
bond strength to enamel is restored. So bonding should be postponed for 1-3 weeks so
that the bond strength is restored, but this waiting period is not always clinically
possible. The use of antioxidants could be a possible solution to immediately restore
the reduced bond strength. Antioxidants could be either synthetic or natural. Although
synthetic antioxidants proved to have the ability to restore bond strength, they have
many adverse effects. Natural antioxidants could be a good alternative to synthetic ones
with no side effects.
Keywords: Antioxidants, Adhesive interface, Bleaching, Catechins, Enamel bond strength, Epicatechin, External antioxidants, Flavonoids, Free radicals, Hydrogen peroxide, Hydroxyl groups, Microshear bond strength, Natural agents, Natural antioxidants, Phenolic compounds, Proanthocyanidins, Reactive oxygen species, Salivary antioxidants, Sodium ascorbate, Synthetic antioxidants, Tocopherol.
