For perforation after tooth extraction, you have to be very careful regarding not to dislodge the clot which is being formed and for that you should not smoke, donot suck anything, or use straw for drinking, avoid aerated drinks etc. You have to take antibiotics along with other meds so that infection does not set in. It will heal by itself if the perforation is small. Keep your follow up with your dentist. For more info you can read the following link in our wesbite.. http://www.identalhub.com/article_do's-and-don'ts-after-tooth-extraction-153.aspx