Tooth whitening is a safe and simple procedure. Tooth whitening works by lightening the outer part of your tooth called enamel. At Precision Dental, our dental office in Glendale, you will receive custom made whitening trays that fit precisely to your teeth along with professional strength whitening gel. Typically the trays and gel are worn for a short time ( 20 to 30 minutes a day) to achieve 7 to 10 shades of increase in brightness. The procedure require no down time so this means that you can get right back into your daily routine.