I had a root canal 5 years ago and immediately after whilst the pain had gone I had a horrible taste in my mouth and the entire bone of the gum on one side felt sore. The dentist checked the site and did an xray and couldn’t see any sign of infection. I waited 6 months and it persisted so I paid again privately to have a 2nd root canal. This helped and the weird taste/ swelling was less frequent. A few weeks ago I had a filling replaced on the tooth next to it and the issue is now back with a vengeance. Awful taste in mouth gum/bone feels like doesn’t belong. When the taste is as its worst I feel like I have a coating on all my surrounding teeth. It’s like it’s been disturbed by the injection or something. As no dentist can ever find anything on an xray im struggling. Want to rip it out. Any ideas welcome thank you