I have a four year old root canal on a molar with crown. tooth #19 Went to dentist for toothache and heat sensitivity with lingering pain as well as cold sensitive. No pressure pain and crown not loose. X-ray shows root canal done properly and opposing teeth are fine. Given two weeks of antobiotics which I've finished and no relief. There is a bit of recession at gum line of this tooth. What do I do now? I have been taking ibuprophen 2-3 times daily for last month.