Which provides low dose (0.7-1 mg/L) fluoride topically on a nearly continuous or high-frequency basis for those consuming it via water?

• A. Fluoridated water
• B. Fluoride toothpaste
• C. Fluoride mouthrinse
• D. Bottled water

Answer: (A)

Fluoride delivered through drinking water at a low, steady level provides ongoing topical exposure to the teeth. When the water is fluoridated at about 0.7–1 mg/L, fluoride is ingested throughout the day as you drink, creating a nearly continuous supply of fluoride in the mouth. This steady presence supports remineralization and helps reduce caries risk without the high, intermittent doses that come with other products.

Fluoride toothpaste delivers much higher concentrations but only during a short brushing window, so its topical effect is strong but not continuous. Fluoride mouthrinse adds another regular source, but still requires deliberate use and isn’t as constant as daily water consumption. Bottled water often has little to no fluoride and can vary greatly, so it doesn’t reliably provide the low-dose, around-the-clock exposure desired.

Therefore, fluoridated water is the method that best achieves this low-dose, nearly continuous topical exposure via water.