Nalgonda technique involves addition of following chemicals:
**Core Concept**
The Nalgonda technique is a method for fluoridating drinking water to prevent dental caries. It involves the addition of a specific chemical to the water supply to achieve a controlled level of fluoride ion concentration.
**Why the Correct Answer is Right**
The Nalgonda technique involves the addition of sodium fluoride (NaF) to the drinking water. This is because NaF is a stable and easily soluble compound that can be accurately measured and added to the water supply to achieve a desired level of fluoride ion concentration. The fluoride ions released from NaF are then absorbed by the teeth, making them more resistant to decay. This process is based on the principle of topical fluoride application, which is a well-established method for preventing dental caries.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because it is not a commonly used chemical in the Nalgonda technique. While it may have some relevance to water treatment or chemistry, it is not the correct answer in this context.
**Option B:**
This option is incorrect because it is not a suitable chemical for the Nalgonda technique. Although it is a fluoride compound, it is not as stable or easily soluble as NaF, making it less suitable for this application.
**Option C:**
This option is incorrect because it is not a fluoride compound at all. It is a different type of chemical that is not relevant to the Nalgonda technique.
**Clinical Pearl / High-Yield Fact**
The Nalgonda technique is an example of a community-based approach to preventing dental caries. By adding fluoride to the drinking water supply, communities can reduce the incidence of dental caries and promote oral health.
**Correct Answer: D. Sodium fluoride (NaF)**