Bleaching techniques of both vital and nonvital teeth are reviewed. Current techniques and their origins are investigated, and the appropriate uses for various methods examined. The current research shows that bleaching, while highly effective, must be viewed with caution. The bleaching process cannot be viewed as entirely benign. The influx of bleaching agents prescribed for home-administration use by dentists is particularly deficient in the amount of independent, refereed research on their long-term effects on oral tissues.