question: Hello doctor,My bottom tooth has a kind of a hole at the gum line. I do not know. When I breathe in, it feels cold like the air went in my tooth. It just does not seem or feel normal. Also, on my upper front tooth, I have some kind of deep line. Example like when you make a line in the sand and it flows into the line but it still stays. It is hard to explain. Is there any way I can fix this without going to the dentist? And yes, I do brush my teeth daily.