I had a root canal done on a molar that had a decayed tooth under a fairly new crown. About a month after the root canal I had to have an abscess removed above said tooth. It’s now been 5 mths and I still have some pain and swelling. Check-ups reveal all is ok, but I’m wondering if there could still be decay on tooth that they maybe didn’t get all of when doing root canal. They only drilled through the crown. I also have red, stinging eyes, some sinus issues. Could this be related?