I'm actually a recent dental grad and wondering when should you perform a root canal on a fractured tooth vs extraction?
if its external vertical root fracture, extract
But what if it is from the mesial ridge into chamber and down the mesial surface of medial root?
Congratulations on entering our profession. Hope you have GREAT career! You ask a really good question. There are many factors that come into play with this decision, but I think the primary one is restorability. Root fractures can't be repaired..they are what they are. Usually the failure is because of the inability of the PDL to attach where the fracture line is, so you build in a periodontal defect. So, if you can extract a segment and still restore with a functional restoration, then that is a reasonable option. In my experience, that rarely occurs. Usually the fracture extends below crestal bone level which pretty much makes it a hopeless situation.
If you are dealing with a tooth fracture not involving the root, then your chances of success go way up and a root canal would be a good option if the pulp is exposed or nearly exposed. If the fracture is due to trauma, then you also need to consider of possibility of resorption, external or internal, and treating for that possibility would be reasonable. All this can increase costs for a patient, so that becomes a factor as well.
As you can see, there is not an easy answer to your question. Patient compliance and understanding is critical and evaluations by specialists will also help in the treatment plan.
Hope this helps.
Gary Backlund DMD, MSD