Just above one of my back tooth on the gum there is a round hole with a hard whitest colored spot. When I touch it with my fingernail it feel hard like a piece of bone. It is not very big, and doesn't really cause any pain. When you touch around it, it is a little sensitive but thats it. I still have my tooth there and like I said it is right where the tooth and the gum meet on the front side. Any Ideas?