A dental disease characterised by mottling of teeth is due to the presence of certain chemical element in drinking water. Which of the following is that element?

Options

A. Fluorine
B. Chlorine
C. Boron
D. Mercury

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a chemical element in drinking water that causes a dental disease characterized by mottling of teeth.

2. **Defining Mottling of Teeth**: Mottling of teeth refers to a condition where the enamel of the teeth appears spotted or discolored. This condition is often linked to certain environmental factors, particularly the quality of drinking water.

3. **Identifying the Cause**: The primary cause of mottling of teeth is the excessive intake of fluoride. When fluoride is consumed in high amounts during the time when teeth are developing (calcifying), it can lead to changes in the enamel.

4. **Naming the Condition**: The dental disease associated with mottling of teeth due to excessive fluoride is known as dental fluorosis. This condition manifests as white spots or streaks on the teeth, and in severe cases, it can lead to brown stains and surface irregularities.

5. **Finding the Correct Element**: Among the options provided in the question, the chemical element responsible for this condition is fluorine (F), as it is the element that forms fluoride when combined with other elements.

6. **Conclusion**: Therefore, the correct answer to the question is fluorine.

**Final Answer**: The chemical element responsible for the mottling of teeth due to its presence in drinking water is fluorine.

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