Question

The soft, sticky layer formed on the tooth which is harmful is
A) Enamel
B) Plaque
C) Dentine
D) pulp

Answer 1

Hint: The teeth are the hardest substances in the human body. Teeth are essential for chewing, and also play an important role in speech.
Parts of the teeth include:
Enamel: The hardest, white outer part of the tooth

Complete answer:
The enamel is the hardest and the outermost layer and is made up of calcium phosphate. Bacteria can form a biofilm called plaque on the surface of teeth and the carboxylic acids produced by these bacteria can cause dental caries or cavities and also sensitivity.

Dentin is the middle layer of the tooth and comprises both minerals and the tubules leading to the pulp. Pulp is the innermost and the softest layer of teeth. It contains living tissue that descends below the gum line along with dentin. If a cavity reaches the pulp, root canal therapy should be done to remove the infection and save the tooth. If the tooth cannot be saved, it may need to be extracted.

Hence, we can say that plaque is a soft, sticky film that builds upon the teeth and contains millions of bacteria. When you eat, the bacteria in plaque use the sugars present in food to produce acids that eat away at the tooth enamel.

So, the correct option is B which is 'plaque'.

Note: Enamel does not grow back once it is lost. To prevent plaque from building up on the enamel and thereby destroying it, remember to brush at least twice a day with a soft-bristled toothbrush, floss every twenty-four hours in order to disrupt bacterial colonies, use fluoridated mouthwash and get a dental cleaning every six months or as recommended by your dentist.