Concentration of F in 1.23% APF gel is (1.23% c)
**Core Concept**
The question is testing the student's knowledge of the concentration of fluoride (F) in acidulated phosphate fluoride (APF) gel, a common dental caries prevention agent. APF gel is a solution of sodium fluoride and phosphoric acid in a gel base, which helps to release fluoride ions at a controlled rate.
**Why the Correct Answer is Right**
The correct answer is 1.23% w/v (weight per volume) of sodium fluoride. This concentration is crucial as it determines the amount of fluoride ions released from the APF gel. The acidulated phosphate fluoride gel is prepared by dissolving sodium fluoride in a gel base, and the concentration is typically expressed as a percentage of sodium fluoride. The 1.23% concentration is a standard concentration used in many dental applications.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not specify the concentration of sodium fluoride in the APF gel.
* **Option B:** This option is incorrect as it does not match the standard concentration of sodium fluoride in APF gel.
* **Option C:** This option is incorrect as it is not a recognized concentration of sodium fluoride in APF gel.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the concentration of fluoride in APF gel can vary depending on the manufacturer and intended use. However, 1.23% w/v of sodium fluoride is a commonly used concentration for dental caries prevention.
**Correct Answer: A. 1.23% w/v of sodium fluoride.**