Hello, Have you has a follow-up visit with your dentist and discussed your symptoms? I suggest an evaluation with a root canal specialist before considering an extraction. There may have been some sinus reaction to your infection and you need time for this to heal completely. Antibiotics may help improve your ability to heal. There are surgical endodontist procedures that can treat resistant infections. Removal of the post and core is possible if you have a reaction to the material, but this should all be contained inside the tooth and canal system. There is something wrong if the post is outside of the tooth or root. Look into all possibilities for treatment before disturbing your bridge. Any loss of a tooth under a bridge can cause removal of the bridge or weaken it. Make sure your periodontal condition is sound and you do not have a unrelated sinus infection. I hope this helps and you are able to retain your tooth with comfort. Thank you for your inquiry.