I am a 45 years old. I had a filling done when I was 16 and about a month ago broke a cusp on the tooth. It had been bothering me before it broke but I assumed it was just sensitive teeth. I have had sensitive teeth for years. However, this it the first molar on the bottom left side of the jaw. The dentist restored half the tooth with an amalgam filling and told me to take it easy on the tooth for a couple of hours. He also suggested I get a cap on that tooth because it was a large filling. I think that I must have clenched without knowing because when I got home and looked in the mirror the restored side of the tooth was kind of collapsed. When the freezing went out the bite seemed off, the tongue constantly gets irritated by the tooth on the inside of the filling. I have been having a lot of problems chewing. It feels like that side of my mouth closes too much and it aches after I finish. I have been back to the dentist twice and the first time he took an xray, shortened what he thought may be high spots in the filled tooth and suggested a root canal. He said it looked like it could be the beginning of a dying tooth. The second time he polished the tooth and wanted to wait 6 weeks before putting on a cap. Recently the wisdom tooth at the bottom left back feels like it did when it came in and the muscles around the back jaw ache on both sides. Could the root canal fix the bite problem? Is the dying tooth the problem? I just want my mouth to feel better, any suggestions?