Question

227. One of the hardest substance of our body is the teeth enamel. It does not dissolve in water but is corroded when the pH in the mouth is below 5.5. How does toothpaste prevent tooth decay? Identify the substance which helps to prevent tooth decay.

Answer 1

• The toothpaste is alkaline which means they are basic.
• Acids present in mouth cause tooth decay.
• So, toothpastes prevent from decay by neutralising the acids present in the mouth.
• Toothpaste contains bases such as calcium hydrogen phosphates (CaHPO₄), calcium carbonate (CaCO3), silica (SiO₂), hydroxyapatite (Calcium phosphate mineral), and mostly sodium fluoride (NaF).
• Fluoride helps prevent cavities and can even treat the earliest stages of tooth damage.
• Fluorides are the main ingredient in toothpaste.