I've had 2 root canals. I tried the filling route first in one of them and ended up in so much pain that they had no choice but to do a root canal. Since it got so bad I now have 3 dark spots in my jaw under the specific tooth. I've seen a dental surgeon twice to ensure that these dark spots that show up on the xray aren't "doing anything weird". So far nothing. I would definately go to the root canal directly next time, not the filling route after this experience.