Why Are Black Lines Forming Around My Dental Crowns?

You’ve just finished brushing, and you pause to admire your smile in the bathroom mirror. Your teeth are white and resplendent, and your gums are vibrantly pink—but a dental crown covering one of your molars catches your attention. Something seems off, and upon further inspection, you notice that a thin black line has formed around the bottom of your crown. You check your other crowns and notice the same imperfection. You have no earthly idea what these lines are or why they’re there, and you begin to feel a little anxious. But there’s nothing to worry about; here’s what’s going on.