There is no pain since there is no nerve left. Even small infections such as this can greatly affect a person's health. Pulling a root canal filled tooth is a bit more expensive since the tooth will have to be replaced with some kind of bridge. I recently learned of an excellent site devoted to the dangers of root canals . There are numerous first-hand accounts .
Some people see major improvement after having all their mercury fillings removed.
Most don't get much improvement. This is a difficult question. I will try to summarize what I know and let you decide. I had mine replaced and I did see some improvement, though not as much as I hoped. I am in no way an expert on this subject.