Why does enamel risk increase when tooth pH goes below 5.5?
Answer and explanation
Correct answer: Acidity can start dissolving enamel
Dental enamel contains mineral crystals mainly based on calcium hydroxyapatite. Bacteria metabolise sugars and produce acids, lowering the pH in dental plaque. When the pH falls below about 5.5, the acidic environment favours dissolution of enamel minerals faster than repair can occur. This demineralisation increases tooth-decay risk, so option A is correct. The other options do not describe the acid–mineral process.
Frequently asked questions
What is the correct answer to this question?
Acidity can start dissolving enamel
Why is this the correct answer?
Dental enamel contains mineral crystals mainly based on calcium hydroxyapatite. Bacteria metabolise sugars and produce acids, lowering the pH in dental plaque. When the pH falls below about 5.5, the acidic environment favours dissolution of enamel minerals faster than repair can occur. This demineralisation increases tooth-decay risk, so option A is correct. The other options do not describe the acid–mineral process.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
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