To protect tooth A. Acidic

B. Neutral

C. Basic

D. Corrosive

Toothpastes we generally contain mild bases such as sodium fluoride or sodium bicarbonate in their composition. The base reacts with the acid formed during tooth decay and neutralises its bad effects thus, preventing tooth decay.

Note:

When we eat sweet things, the pH of our mouth falls below 5.5 (moderately acid) as the oral bacteria releases lactic acid while acting on sugars. The acidic conditions are capable to corrode the enamel as these are made up of calcium phosphate. This makes the tooth decay.