Question

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

Answer 1

1. Tooth decay starts when the pH of the acid formed in the mouth falls below 5.5. This is because the acid becomes strong enough to attack the enamel of our teeth and corrode it. This sets in tooth decay.
2. Though tooth enamel is made of calcium phosphate (which is the hardest material in our body), it starts getting corroded when the pH in the mouth is lower than 5.5