Fluoride to be present in water (mg/1,) to prevent caries –
**Core Concept**
The addition of fluoride to community water supplies is a widely practiced public health measure aimed at reducing the incidence of dental caries. This practice is based on the concept of community water fluoridation, which involves the controlled addition of fluoride ions to the public water supply to achieve a concentration that is optimal for caries prevention.
**Why the Correct Answer is Right**
Fluoride is a naturally occurring ion that plays a crucial role in the prevention of dental caries. When ingested in optimal amounts, fluoride promotes the remineralization of tooth enamel, making teeth more resistant to acid attacks from plaque bacteria and sugars. The optimal concentration of fluoride in water for caries prevention is 0.7-1.2 mg/L, as recommended by the World Health Organization (WHO). This concentration allows for the optimal balance between caries prevention and the potential for dental fluorosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely too low, as fluoride concentrations below 0.7 mg/L may not provide adequate caries prevention.
* **Option B:** This option is likely too high, as fluoride concentrations above 1.2 mg/L may increase the risk of dental fluorosis.
* **Option C:** This option is not a valid concentration of fluoride in water, making it an incorrect choice.
**Clinical Pearl / High-Yield Fact**
The optimal concentration of fluoride in water for caries prevention is a balance between the benefits of caries prevention and the risks of dental fluorosis. The American Dental Association (ADA) recommends that community water fluoridation programs aim for a concentration of 0.7-1.2 mg/L.
**Correct Answer:** D, 1.0 mg/L