The best time to brush your teeth is once in the morning about an hour after eating breakfast (or drinking coffee) and again at night before you go to bed. Some dentists recommend also brushing a third time every day after lunch. While removing food debris before bacteria gets a chance to proliferate is always a good idea, it is entirely possible to overbrush. If you do decide to brush your teeth following a meal you will want to be sure to wait for about one hour after eating. This will give your teeth a chance to remineralize after an acidic meal. For most people, I recommend sticking to a morning and evening brushing routine and flossing during the day and after meals when necessary.