question: Hello doctor, My lower molar root canal was done a year back. After that, a metal-ceramic cap was placed. A few months later, my cap was replaced with zirconia supreme because of throbbing below the cap. My dentist advised that because of metal there may be a possibility of some allergic reaction. So, I should replace the cap. Now just two weeks back, I replaced but now I have a bulge in the jaw with pain.