Amount of reduction in dental caries achieved by dentifrices is:
**Core Concept**
The underlying principle being tested is the effectiveness of dentifrices, specifically **fluoride toothpaste**, in preventing dental caries. Dental caries is a bacterial infection causing demineralization of tooth enamel, and **fluoride** plays a crucial role in its prevention.
**Why the Correct Answer is Right**
The correct answer is based on the established efficacy of fluoride dentifrices in reducing dental caries. **Fluoride** works by promoting the remineralization of tooth enamel, making teeth more resistant to acid attacks from plaque bacteria and sugars in the mouth. This process involves the substitution of **hydroxide ions** with **fluoride ions** in the enamel, creating a more stable and resistant tooth structure.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the reduction in dental caries achieved by dentifrices is not as low as this option suggests.
**Option B:** This option underestimates the proven efficacy of fluoride dentifrices.
**Option D:** This option overestimates the reduction achieved by dentifrices.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **fluoride toothpaste** is a cornerstone in the prevention of dental caries, and its regular use can significantly reduce the incidence of caries. The **correct concentration of fluoride** is crucial for its effectiveness.
**Correct Answer:** C. 20-40%