Perfecta is proven effective and reliable since 1990. Perfecta 16% can remove a full range of stains including those resulting from tobacco, dark beverages and even tetracycline. Wear time can be adjusted for light stains and for those patients with a history of thermal sensitivity. Perfecta 21% can remove Tetracycline stains. It is recommended that 21% dispenses only to compliant patients with no history of thermal sensitivity.