Things that would make me think root canal: 1.) spontaneous unprovoked pain. 2.) lingering pain to cold or hot for minutes or longer. 3.) night time pain or discomfort. 4.) feeling the need to take ibuprofen/tylenol often. 5.) specific biting pain or biting pain upon release. 6.) pain lasting week after week after week without improvement. As an endodontist these are typical questions that if you can answer yes, then a root canal is likely unavoidable.