Indications for using a 10% carbamide peroxide material in a custom-fitted tray to whiten teeth include teeth discolored from aging, chromogenic foods and drinks, and smoking, and also brown fluorosis-stained teeth, single dark teeth, and tetracycline-stained teeth. Tetracycline-stains may require 2 to 6 months of nightly treatment, whereas after discolorations generally resolve in 2 to 6 weeks. After an initial relapse in the first 2 weeks after the end of treatment, color tends to be stable for 1 to 3 years, with some treatments being permanent. The ADA has approved only six 10% carbamide peroxide materials, which have extensive research and publications on safety and efficacy. Considering the average cost of $196 per arch, and the noninvasive nature of this treatment, nightguard vital bleaching is probably the safest, most cost-effective, patient-pleasing method to improve the appearance of a smile. However, it should be supervised by a dentist for the proper examination, diagnosis of the cause of discoloration, treatment options, and fabrication and fitting of the carrier. Sensitivity during whitening may be treated with fluoride and potassium nitrate.