What is the concentration range for OTC fluoride rinse (NaF or SnF2)?

• A. 900 ppm
• B. 12,300 ppm
• C. 1000-1500 ppm
• D. 200-1000 ppm

Answer: (D)

OTC fluoride rinses are formulated to deliver fluoride ion concentrations in a low to moderate range to provide caries protection while staying safe for daily use. For sodium fluoride rinses available over the counter, a typical concentration is about 0.02%, which corresponds to roughly 200 ppm fluoride. For stannous fluoride rinses, common OTC strengths around 0.4% yield about 970 ppm fluoride. Putting these together, the practical range you’d expect for OTC fluoride rinses—whether using NaF or SnF2—is roughly 200 to 1000 ppm. This is why the range 200–1000 ppm is the best answer: it encompasses the fluoride levels provided by common OTC NaF and SnF2 products. The other options don’t fit the typical spectrum: a single value, an unrealistically high level, or a range that doesn’t include the lower, widely used OTC concentrations.