Plaque, the sticky, almost invisible film that forms on your teeth and causes gum inflammation, can harden and turn into a new material called Calculus.
Calculus is hardened plaque that is firmly attached to the tooth surface above and below the gum line, and can only be removed with special dental instruments. Removing Calculus from the tooth surface above the gum line is called Scaling.
When Calculus must be removed from the root surfaces of the teeth, the careful cleaning of the periodontal pockets and tooth root surfaces is called Root Planing.