Essentially, responsibility for developing and implementing measures designed to control dental caries should rest with the dental profession. Many of the most effective ways of controlling caries, however, involve the use of fluoride. Either systemically via fluoridated water and tablets or, topically, with fluoride-containing toothpaste and mouthrinses. Scientists in many disciplines are aware that fluorides can, in certain circumstances, endanger the environment. There is some evidence that fluoride contamination of the total environment has increased in recent years. The usefulness of fluoride as a caries preventive does not mean that unnecessary exposure to the element should be tolerated. It is conceivable that fluoride is approaching the limits of its effectiveness as a caries preventive. With this possibility in mind, recent research directed toward the development of safe, effective anti-tooth decay vaccines has been reviewed.