Your teeth are one of the few parts that can't properly repair themselves once the damage reaches the hard outer layer.

The outside of your tooth is covered by enamel, which is the hardest substance in the human body.

Sounds like it should be almost indestructible, right? 😂

Not quite.

Enamel can actually lose minerals when exposed to acids from your mouth. Your saliva can help put some minerals back into the enamel and repair very early damage.

But once enamel is seriously damaged and a cavity has formed, your body can't simply grow a brand-new piece of enamel to replace it.

That's because mature enamel doesn't contain living cells that can produce more enamel after the tooth has developed.

And underneath the enamel is dentin, which is living tissue and can respond to certain types of damage. But it still can't completely rebuild a badly damaged tooth the way your skin can heal a cut.

So your teeth are incredibly strong...

but they're not exactly great at self-repair. 😭

This is one reason brushing, cleaning between your teeth and regular dental care matter so much.

Quick fact: Enamel is the hardest tissue in the human body, but once it's significantly damaged, it can't regenerate itself.