Unfortunately they tend to have little science behind them. If a toothpaste is fluoride free I would not recommend it.

不幸的是，它们往往没有科学依据作支撑。如果牙膏不含氟我是不会推荐的。

youdao

In some areas of the country, the natural water supply contains a certain amount of fluoride - enough to keep teeth healthy and free of cavities.

在我国的某些地区，自来水含有一定量的氟化物——足以保持牙齿的健康及有效防止蛀牙。

youdao

But it is a temporary solution and if we want to control the fluoride pollution, we must use opaque glass with fluorine-free.

为此，但只是治标不治本，要根本上防治氟化物的污染，在于用无氟乳浊玻璃。

youdao

Dentist Bill Dorfman, the Los Angeles-based founder of tooth-whitening company Discus Dental, scoffs at the many fluoride-free brands on the market.

WSJ: Deluxe Toothpastes: Brush With Greatness

Feeling defensive and uncomfortable with the story's bleak implication for our marriage, I blurted out that I hated his useless fluoride-free Tom's and his organic shower gel that smelled like rotten mangoes, and that I couldn't live by his tyrannical eco standards.

WSJ: Deluxe Toothpastes: Brush With Greatness