Regardless of the mechanism, neutralizing oral acid is a primary goal for preventing or treating caries, erosion, and candidiasis infections. Caries and erosion are classified as pH-mediated conditions. Repeated acid attacks eventually damage enamel, dentin, and cementum. Acidic pH also sets the stage for the development of oral fungal infections. A variety of situations allow the oral pH to become acidic: frequent intake of acidic foods and beverages or fermentable carbohydrates, medical conditions involving regurgitation, acidic stomach acid vapors, insufficient salivary flow, poor-quality saliva, xerostomia, and high numbers of acid-producing microbes.