Fluoride helps protect your teeth from the acid that is released when this happens. It does this in two ways.

氟能够通过两个途径在细菌新陈代谢是你口腔成为酸性的时候保护你的牙齿。

youdao

First, fluoride makes your tooth enamel stronger and less likely to suffer acid damage.

首先，氟能够使你牙齿的釉质更坚固，同时降低酸性的腐蚀程度。

youdao

The oxide (which comes from an ore called coltan) is converted to a fluoride using hydrofluoric acid, and the fluoride is then reduced with liquid sodium.

FORBES: What On Earth Is The Economist Talking About Here?