Question

Explain the pH change as the cause of tooth decay. How can tooth decay caused by pH change be prevented?

Answer 1

When the pH of the mouth falls to around 5.5, tooth decay begins. As the acidity in the mouth increases, the acid reacts with the tooth enamel and causes tooth decay. 
Tooth decay can be prevented by brushing with toothpastes (which are basic and neutralise the acid formed) regularly and by cleaning the mouth carefully after meals.