I recently chipped one of my bottom back molars. The tooth had a very large filling. However, it seemed like the dentist really 'went to town' on the drilling. A week later I still had pain and got a prescription. My new crown is in with temporary cement to "see if the pain goes away," and I'm told I may need a root canal!
Question: How common is it for one to go in for a crown and wind up needing a root canal?
Question: Could the dentist have precipitated the need for a root canal from being overzealous with the drill?

It is very common that teeth that are crowned or needing a crown will also need a root canal. It's actually better if the root canal is done before the crown is place so that a hole doesn't have to be drilled through the crown.

Teeth with large fillings are always candidates for crowns. Teeth with large fillings have usually be filled and refilled before a crown is suggested. The more a tooth is drilled upon the greater the chance of the tooth dying. A root canal is done on dead teeth.

If teeth could talk they would say "fix me right the first time."