<P> It has been found that milk and certain kinds of cheese like cheddar cheese can help counter tooth decay if eaten soon after the consumption of foods potentially harmful to teeth . </P> <P> As of 2015 the evidence concerning use of xylitol (a sugar alcohol) in chewing gum was insufficient to determine if it is effective at preventing caries . </P> <P> The use of dental sealants is a means of prevention . A sealant is a thin plastic - like coating applied to the chewing surfaces of the molars to prevent food from being trapped inside pits and fissures . This deprives resident plaque bacteria of carbohydrate, preventing the formation of pit and fissure caries . Sealants are usually applied on the teeth of children, as soon as the teeth erupt but adults are receiving them if not previously performed . Sealants can wear out and fail to prevent access of food and plaque bacteria inside pits and fissures and need to be replaced so they must be checked regularly by dental professionals . </P> <P> Calcium, as found in food such as milk and green vegetables, is often recommended to protect against dental caries . Fluoride helps prevent decay of a tooth by binding to the hydroxyapatite crystals in enamel . Streptococcus mutans is the leading cause of tooth decay . Low concentration fluoride ions act as bacteriostatic therapeutic agent and high concentration fluoride ions are bactericidal . The incorporated fluorine makes enamel more resistant to demineralization and, thus, resistant to decay . Topical fluoride is more highly recommended than systemic intake such as by tablets or drops to protect the surface of the teeth . This may include a fluoride toothpaste or mouthwash or varnish . Standard fluoride toothpaste (1,000--1,500 ppm) is more effective than low fluoride toothpaste (<600ppm) to prevent dental caries . After brushing with fluoride toothpaste, rinsing should be avoided and the excess spat out . Many dental professionals include application of topical fluoride solutions as part of routine visits and recommend the use of xylitol and amorphous calcium phosphate products . Silver diamine fluoride may work better than fluoride varnish to prevent cavities . Water fluoridation also lowers the risk of tooth decay . </P>

Who discovered that fluoride is related to the prevention of dental caries