Dental cavities and gum disease disproportionately impact low-income and rural communities. The major culprit is tooth decay, caused by a buildup of acid and plaque. Researchers are developing a tool that may someday help dentists identify high acidity. It is a hand-held device that can assess the amount of acidity in the plaque on teeth and could also be used in homes and by health workers in schools and rural clinics. Learn more on NSF’s “The Discovery Files.”