What causes plaque ?

Explanation

1. Mineral salts like calcium and magnesium are deposited on the teeth and form a hard layer of 'tartar' or calculus called palque.
2. If the palque formed on teeth is not removed regularly, it would spread down the tooth into the narrow gap between the gums and enamel and causes inflammation , called gingivitis , which leads to redness , bleedings of the gums and bad smell.