Which fluoride application method is noted for its highest ppm absorption into enamel?

Fluoride varnish is recognized for its high rate of absorption into the enamel due to its concentrated formula and the manner in which it adheres to the tooth surface. When applied, fluoride varnish forms a sticky coating that effectively bonds to the enamel, allowing for a prolonged release of fluoride into the tooth structure. This ensures a higher concentration of fluoride ions is delivered directly where it is needed most, promoting remineralization of demineralized enamel and enhancing resistance to decay.

Compared to other fluoride application methods, fluoride varnish offers a more sustained interaction with the enamel, which is crucial for effective uptake. Fluoride gel and mouth rinses are effective as well, but their application methods and duration of contact do not facilitate the same level of absorption. Toothpaste provides fluoride with each brushing but typically does not reach the same concentration level in enamel as varnish, especially since it is rinsed away after use. Thus, fluoride varnish stands out as the method that delivers the highest parts per million (ppm) absorption into enamel.