There could be the infection of the tooth or maybe the teeth.
What kind of dental work did you go through.The tooth might be inflamed and the radiating pain you are describing is not uncommon with inflamed or infected teeth.If you have had a filling done then maybe the filling is too close to the nerve inside the root canal,but RTC is the best treatment for the infected tooth,You will have to see the dentist again in order to find out the reason for your problem.Only after resolving it, will you get relief from the pain.
What kind of work was done?