I brush my teeth twice a day. I use mouthwash and floss once a day. These brown stains are new, and my dentist mentioned that I have some my last visit maybe a month or two ago, but I'm just seeing them really appear.
I usually brush my teeth for about 6 minutes straight. Wondering if that has to do anything with it. I've heard of bacteria being the reason..? If you know the science behind it and explained it to me I would feel much better.. LOL.