Several years ago, I went to the dentist and asked what that was on my molar (black spot). I knew it went wrong when the tech told the dentist I was having problems with that molar (it had been filled once before). No it was not bothering me. The dentist then began to drill out the old filling and put in new, I thought he was working on that black spot on the side of the tooth. Long story short, it was not covered by my insurance - I was out of area and had to pay the majority. Lesson learned call ahead to see if that dentist is on your ins. and two get second opinun on major work.