"Hydroxyapatite is natural. It is a type of calcium that makes up bones and teeth," says Lai. "Nano-hydroxyapatite relates to ...

From sensitive teeth to bad breath, these are the toothpastes that cover it all.

We don’t always have the answers, but we have some people on speed dial who do — which is why we present our FYI series, where we have experts explain if lip balm is actually bad, how often you should ...