Hardened plaque. Calcium salts produced by saliva harden any plaque which is left on the surface of teeth. These deposits are particularly liable to build on the tooth surfaces nearest to the salivary ducts beneath the tongue and in the cheeks close to the upper first molars. The presence of calculus indicates an alkaline saliva and a low risk of caries or decay. Smoking tends to encourage calculus formation. The build up of calculus must be controlled by scaling of the teeth otherwise gingivitis and the breakdown of the tooth attachment can occur.
