Question

Why does tooth decay start when the pH of mouth is lower than 5.5?

Answer 1

Tooth enamel is made up of calcium phosphate and is the hardest part of the body. When the pH in the mouth goes down and becomes 5.5, it is strong enough to corrode the enamel of the tooth. The mouth turns acidic because the bacteria present in it produce acids by breaking down sugar and food particles left behind in it after eating.