Dental caries is a disease of hard tooth structure caused by bacteria which are living in the mouth and are able to multiply in dental plaque. These bacteria metabolise sugars contained in food and release acids which then demineralise the enamel and the dentine. The bacteria progress further into the tooth substance, and if they reach close to the tooth pulp (nerve), it may cause thermal sensivity and toothache. At an advanced stage, the tooth may react painfully when biting or knocking. Dental caries mostly begins to form in between the teeth and in pits and fissures on the surface of side teeth. In many cases, it can be recognised by dark shadows on chewing surfaces and between the teeth. To protect your teeth and avoid cavities, regular dental cleanings, sealing chewing surfaces, fluoridation, and last but not least a careful and regular at-home oral hygiene are essential.