Hydrogen Peroxide vs. PAP+ While both peroxide and PAP+ are effective in whitening teeth, some studies reveal that PAP+ is superior to HP. PAP+ has been shown to alter a range of chromogens, including polyphenols. Polyphenols are organic molecules found in food and beverages such as red wine and tea. They can be oxidized by phthalimidoperoxycaproic acid to quinones and then potentially undergo further rearrangement reactions.8 Studies also conclude that PAP+ does not alter the integrity of the enamel, while peroxide-based agents reduce the microhardness of the enamel.8 PAP+ works quickly and has been proven to enhance the enamel color by eight shades in just six 10-minute treatments.8 Considering the relative newness of this agent, ongoing studies may be necessary to validate its safety and effectiveness further. Teeth Whitening Today The active ingredient in most teeth-whitening agents today is peroxide, which is delivered as either hydrogen peroxide (HP) or carbamide peroxide (CP). Both agents work to oxidize the chromogens ‒ or darker shades of the tooth ‒ by relying on free radicals to produce a lighter shade.5 Carbamide peroxide is an adduct of hydrogen peroxide; in other words, it is a stable complex that breaks down in contact with water to release hydrogen peroxide.5 Therefore, almost all whitening agents contain hydrogen peroxide. These agents can be found in multiple delivery methods, including in-office whitening, take-home custom trays, whitening strips, prefabricated trays, pens, and pastes. Unfortunately, peroxide-based whitening agents have been known to create reversible pulpitis or tooth sensitivity