Isn't hydrogen peroxide used in teeth whitening treatments?if so,is it true that it can erode the tooth enamel over time?in that case what is the percentage of hydrogen peroxide that can cause it?what about carbamide peroxide?

Regardless of which peroxide is in the gel, the concentration is low enough to help prevent damage to your teeth and gingiva as long as it is used according to directions and not overused. People often don't follow the directions and that's when damage can occur.

The carbamide peroxide gel contains between 10%- 44%, which is equivalent to a 3%-16% of hydrogen peroxide concentration. Anything stronger than these concentrations can and will result in enamel destruction.