Berlin - Wait a half hour to brush teeth after drinking an acid-heavy drink like a cola or orange juice, the Federal German Association of Apothecaries recommends. The acids can aggravate the tooth enamel, which can then be brushed loose by a toothbrush's bristles, says the group. Waiting half an hour lets some of the minerals loosened get reabsorbed by the enamel.
The 30-minute rule applies generally after drinking any juice or lemonade, says Ursula Sellerberg of the group, since most juices, with exceptions like peach juice, are highly acidic. Tee, coffee, beer and wine all have lower acidic levels.