When teeth are not cleaned properly they become coated with a sticky substance called plaque. This consists of food remains, the bacteria that feed on them, and the bacterial waste products such as acids. Plaque and enamel staining are usually removed with a rotary polisher and polishing paste. Calculus (scale) is a hard deposit which forms when the plaque on the tooth surface is not cleaned away but instead is allowed to build up and harden. It may be found on the exposed teeth and, in more severe cases, on the tooth roots below the gum line. In the treatment of gingivitis (inflammation of the gums) and periodontal disease (destruction of the bone and supporting structures of the tooth), calculus is removed using hand-scaling instruments or an ultrasonic scaler. The latter relies on ultra-high frequency vibrations from its oscillating tip and a water spray to break up and remove the debris. A powerful air-and-abrasive spray has been developed for calculus removal and is particularly effective in cleaning stains from the teeth.
If gingivitis has progressed to periodontal disease, thorough cleaning of the tooth’s root surface under the infected gum may be needed. The dentist may prescribe a course of root planing, carried out under a local anaesthetic, to thoroughly clean and remove infected tissue from beneath the gum line on the root surface.