text: is this true? is it true that if you brush your teeth within 30 minutes of eating something you actually can promote the formation of cavities?  someone once told me that when you eat it weakens the enamel on your teeth, and if you brush your teeth straight after it can promote cavities because you're kind of rubbing the sugar straight into the teeth........  anyway, i've been believing that for years, but it means i can't brush my teeth after breakfast because i don't have time to wait 30 minutes after eating before i have to leave the house, so i usually just stick some chewing gum in my mouth instead.  is it actually true?! no!  i've never heard that before. in four years of dental school and countless continuing education seminars.   absalutely not,  brushing generates saliva and rinsing,  all this activity in your mouth can only help dilute the sugars, and the fluoride will integrate with the enamel even more after a meal.    can't get into specifics without regurgitating the first year tooth chemistry, but please ya gots ta believe me.  that is not true.   now go brush yer teeth