qqp question1: I have a small black line on my molar, and it shows no signs of pain or sensitivity. What is it? What do I do? question2: Dentistry: My upper right Rear Molar (wisdom tooth) broke about 10 years ago. Only one small piece is left above the gum line. It has never caused any pain and is not loose. Since it has not caused any pain in 10 years, is it ok to not have it extracted?