As someone that managed a dental office for for 3 years. If you got an amalgam filling wait a day. If you got a composite your fine. The same goes for drinking through a straw. I have seen people who have gotten amalgam fillings and pulled them out by smoking and drinking through straws. The composite fillings should have been set with a uv light so they are in there very good and once you're not numb your good to go. Unless you had fillings on multiple teeth or surfaces. If you did then you're mouth may be sore and you may want to wait.