Tooth decay, known formally as dental caries, has been a serious health problem for all nations since time immemorial. For centuries, tooth decay was thought to be the handiwork of an elusive and, in some cultures, evil tooth worm that gnawed holes into the white, highly mineralized enamel and left all those in its wake in pain. But superstition has yielded to science and its explanation that certain oral bacteria discharge mineral-eroding acid onto the enamel, starting the gradual process of decay. Over the last several decades, dental researchers have made tremendous progress in defining and learning to thwart the decay process. This work has involved the three-pronged strategy of discovery, innovation, and prevention - and produced one of the major public health success stories of the 20th century.
Tooth decay was considered an irreversible disease process — once a cavity started, the only remedy was to drill out the decay and fill the tooth with a restorative material.
Tooth decay is no longer the national epidemic it was a few generations ago. Millions of American children now have little or no decay, and total tooth loss or edentulism is now much less common. Without research progress in the fight against dental caries and periodontal diseases, there would be an additional 18.6 million Americans age 45 and older with none of their natural teeth.
Prevention is now the mantra in American dentistry. In addition to improved products to fight tooth decay, more people benefit from preventive dentistry, including the use of fluorides and dental sealants to prevent decay. Compared to previous years, these techniques have made it possible for millions more people to keep their natural teeth for a lifetime. It is estimated that from 1979 through 1989 alone, the American public saved more than $39 billion in dental expenditures due to the power of prevention. Since the 1950s, the total federal investment in NIH-funded oral health research has saved the American public at least $3 for every $1 invested.