###Human: What can cause sores in the mouth with tooth pain? ###Assistant: Hello. I have been through your query and I can understand your concern. The multiple sores you referred to surrounding your back tooth are the sinuses from the periapical infection (attachment removed to protect patient identity). This occurs when there is infected pulp tissue (inner part of the tooth) and there occurs pus formation at the bottom of the root of the tooth. Now when this pus gets more and more formed, it tries to push the surrounding tissue to come out of the tissue. This leads to the formation of the sinus. It is characterized by sore mouth taste frequently and also if the infection is acute, there may be a pain in the tooth. Here the filling you have in the tooth might be the cause of the infection as sometimes the fillings when old and not routinely checked to develop cracks (especially amalgam or silver metal fillings) which lead to the entry of microorganisms into the inner tissue of tooth leading to pus formation. I would advise you to have a visit to your nearest dentist and get an X-ray for the tooth. The tooth may require a root canal treatment (confirmed on the X-ray). Meanwhile, you may take an analgesic for the pain and an antibiotic for the infection for three days. If you were not allergic to these medicines, I would suggest you take Aceclofenac 100 mg when there is a pain in the tooth, and Amoxicillin plus Clavulanate 625 mg two times daily for three days and then visit a dentist. Also, maintain the good oral hygiene by brushing, flossing and using oral rinses regularly.