In the 19th century, research on fluoride and its occurrence in teeth and bones was carried out by physicians and chemists in Europe while the dental profession was still not organized as we know it today. The analytical methods of the time were quite limited and the results rather controversial.
Sodium fluoride is an ionic compound with the formula NaF. This colourless solid is the main source of the fluoride ion in diverse applications. NaF is less expensive and less hygroscopic than KF, but otherwise the potassium salt is more widely used.
Chemical structure and properties
NaF crystallizes in the sodium chloride motif where both Na+ and F− occupy octahedral coordination sites.
It is usually used as a reagent for the synthesis of fluorides. Representative substrates include electrophilic chlorides including acyl chlorides, sulfur chlorides, and phosphorus chloride.
Like other fluorides, NaF finds use in desilylation in organic synthesis.
uses
Fluoride salts are used widely to enhance the strength of teeth by the formation of fluoroapatite, a naturally occurring component of tooth enamel. In the US, NaF was once used to fluoridate drinking water but its use has been displaced by hexafluorosilicic acid (H
2SiF
6) or its sodium salt (Na
2SiF
6). Toothpaste often contains sodium fluoride to prevent cavities.