[Coder-san]

It was not long ago that I had so much sleep deprivation that one of my front teeth got kind of transparent and slowly turned black. (I only got 4-5 hours sleep every day for weeks -- real parents do not sleep, do they?)
I didn't connect these events first, but as soon as I got enough sleep the tooth turned to shining white again (pun intended). That was amazing.

So one of your tooth is also a member of HC? Awesome.