Tooth Decay
Tooth decay is the damage of tooth enamel caused when acids in the mouth lower the pH and slowly dissolve the hard outer layer.
Practice This ConceptMain explanation
Teacher explanation
Bacteria in the mouth feed on sugar left on teeth and produce acids. These acids lower the mouth pH. If the pH falls below about 5.5, enamel starts getting damaged. This is why regular brushing, reduced sugar intake, and fluoride toothpaste are useful habits.
Example
After frequent sweet snacks, the mouth becomes more acidic and the enamel can start weakening.
Simple analogy
Sugar feeds bacteria, bacteria make acid, acid harms enamel.
Common confusion
Students often think tooth decay is only about dirty teeth. The main issue is the acid made by bacteria and the drop in pH.
Exam tip
In exam answers, mention sugar, bacteria, acid formation, pH drop, and enamel damage together.
Answer writing and exam use
1-mark use
Write the exact meaning of tooth decay in one clean line.
2-mark use
Define tooth decay and add one example or condition.
3-mark use
Explain tooth decay, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
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