Concentration of Ingredients Used in Oxidative Whitening
There are a wide range of concentrations of applied bleaching ingredients in the dental field. Hydrogen peroxide concentration ranges from up to 35% (in-office applications with rubber dams) to lesser amounts in take home and OTC preparations. Originally, the dentist-applied tray systems were limited to concentrations of carbamide peroxide of 10% or so (about 3.3% peroxide) because of soft tissue tolerability, although today various kits used at home have concentrations up to 35% carbamide peroxide – around 11.7% as hydrogen peroxide and up to 14% hydrogen peroxide in strip applications where the total dose of whitening chemistry is highly controlled.
High concentrations of bleach tend to produce more robust whitening in shorter time – however improved whitening speed is accompanied by side effects of sensitivity and soft tissue irritation. The relation of efficacy with side effects has been summarized by Kugel et al.30 as a tradeoff between performance, in particular the rate of whitening with the development of side effects of hypersensitivity.