What product is generally painted on the facial surfaces of teeth in a brush-on whitening method?

In the brush-on whitening method, the product that is typically applied to the facial surfaces of the teeth is peroxide. This is because peroxide, specifically carbamide peroxide or hydrogen peroxide, acts as a bleaching agent that penetrates the enamel and breaks down stains on the teeth. The application allows for controlled whitening, targeting areas most in need of improvement.

Fluoride gel is primarily used for remineralization and strengthening teeth, rather than for whitening purposes. Cleansing foam serves a different role by helping to clean the teeth and remove surface debris, but it does not have the whitening effect that peroxide does. An anti-microbial rinse is used for reducing bacteria and improving oral hygiene, and while it is beneficial for overall dental health, it does not contribute to tooth whitening. Thus, peroxide is the correct choice for this whitening method due to its active role in achieving a lighter tooth shade.