Dino, the general rule is to observe for 2 weeks and have it biopsied if there isn't a change or the site gets worse. So your dentist gave good advice to wait a bit. If in a week or so it isn't improved, I would recommend that you go to an ENT familiar with oral cancer, preferrable at a comprehensive cancer center, and have him/her take samples for biopsy. Remember that most oral problems are not cancer. However, just to be sure, keep an eye on it and have it looked at if it doesn't improve.