A crust like, hard deposit, also called tartar, found on the roots and crowns of the teeth. Calculus forms when mineral salts in saliva are deposited in existing plaque, a coating of debris and mucus that forms on the teeth.
There are two different types of dental calculus. Subgingival calculus forms below the gum margin, is more evenly distributed around all the teeth, and is black or brown. Supragingival calculus is a white or yellowish deposit that forms above the gum margin, on the crowns of teeth in areas close to the openings of salivary gland ducts.
Both types of calculus are difficult to remove as they are hard. The subgingival variety can be even more difficult to remove because of its location and degree of calcification.
Effects and treatment
The toxins apparent in calculus can lead to gum inflammation (gingivitis) which can progress to the destruction of the supporting tissues (peridontitus). Calculus should be removed on a regular basis by professional scaling done by a dentist or hygienist. Vigilant attention to oral hygiene can reduce the recurrence of dental calculus.