Calculus is formed by plaque that accumulates on teeth and undergoes calcification, if not properly cleaned and removed through brushing, it remineralises. At that stage it has become very hard and is impossible to be removed at home.
Residues of bacteria lead to gingivitis, periodontitis, tooth sensitivity as the gums shrink and the roots are exposed. Bacteria that enter the blood circulation can cause more serious health issues such as heart, joint, kidney diseases or even miscarriage in pregnant women.