(Science: dentistry) a calcium salt concretion which forms on your teeth.
calculus deposits form on the teeth in areas which you do not floss or brush. If these concretions are left to build up on the tooth enamel, they will irritate the gum tissue, push it away from the tooth and promote progressive bone loss.
Eventually the teeth can loosen and fall out. These deposits can be removed by a dentist or a dental hygienist on an annual to biannual basis.