First flouride varnish discovered in Europe has what percentage of NaF
## **Core Concept**
The question pertains to the composition of the first fluoride varnish discovered in Europe, specifically asking about the concentration of Sodium Fluoride (NaF) in it. Fluoride varnishes are widely used in dentistry for the prevention of dental caries. They work by providing a high concentration of fluoride ions that can be absorbed by tooth enamel, making teeth more resistant to acid attacks from plaque bacteria and sugars in the mouth.
## **Why the Correct Answer is Right**
The correct answer, **22,600 ppm (or 2.26%) NaF**, corresponds to the concentration found in the fluoride varnish known as Duraphat, which was indeed one of the first fluoride varnishes introduced in Europe. This product contains 5% sodium fluoride (NaF) solution, which equates to 22,600 ppm fluoride. The mechanism behind fluoride varnishes like Duraphat involves the release of fluoride ions, which then interact with tooth enamel to form fluorapatite, enhancing tooth resistance to decay.
## **Why Each Wrong Option is Incorrect**
- **Option A: 12,000 ppm**: This concentration is lower than what is found in Duraphat. While there are various fluoride varnishes with different concentrations, 12,000 ppm does not match the composition of the first fluoride varnish discovered in Europe.
- **Option B: 5,000 ppm**: Similarly, this is a much lower concentration than that of Duraphat and does not represent the first fluoride varnish introduced in Europe.
- **Option D: 38,760 ppm**: This option suggests a much higher concentration than what is known for Duraphat or commonly used fluoride varnishes, making it incorrect.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that fluoride varnishes, such as Duraphat (which contains **5% NaF or 22,600 ppm fluoride**), are crucial in preventive dentistry. They are applied directly to teeth to prevent caries and are particularly recommended for patients at high risk of dental caries. The application of fluoride varnishes is a simple, effective, and painless procedure.
## **Correct Answer:** . **C. 22,600 ppm**