We have the habit of immediately brushing our teeth after having a meal, but new studies suggest we wait at least 30 minutes to 1 hour. This is because the acids in many foods soften tooth enamel, making it vulnerable to damage from brushing. When you wait, the acids will have cleared and the enamel will have re-hardened. You can't speed the process so don't think about short cuts. Rinsing your mouth won't make a difference either.