u/Key_Perspective3299

I'm super embarrassed to post this, but what is this black thing? I've checked and it's not a hole? It feels like a tiny peice of something but I don't know what. Context: When I was 13 a small peice of tooth fell out. I wasn't able to see a dentist for 9 years because it was very hard to get one where I live. I went about a month or two ago expecting the worst, but they told me my teeth are fine. I left so confused because I swear there's multiple visible problems with my teeth.