I have my textbooks open when I work. It’s much easier to figure these things out then…

You’re welcome. Your entrecard picture shows us 2 things: you’ve got at least four fingers and two eyes. Don’t know if you’re hiding something behind the camera though.

Jeanie: Such a simple question, but a very complicated and somewhat controversial answer. Some recent research (Kim et al) shows the prognosis of surgery at the mid 90% range, older studies vary quite markedly (from as low as 45%, 65%, and up). This variation is complicated to explain, but has to do with followup periods, classification of healing, surgical techniques, and case selection.

The general consensus is that the prognosis is dependent upon case selection (quality of pre-existing endodontic treatment, location of tooth, presence of a lesion, fractures/perforations). Surgical technique likely plays a huge role in the success as well (ie. microsurgery with ultrasonics vs the old fashioned way with heavy bevels and high speed burs). Chronically infected cases with coronal leakage do more poorly with any sort of therapy, non-surgical or otherwise. However, when you consider that with surgery you are trying to trap bacteria inside a tooth and not allow them out, versus retreatment where you are trying to kill the bacteria inside a tooth, which do you think would be more successful?

Retreatment is generally more predictable (decent prognosis with a more narrow variance) than surgery but again is dependent upon the case (fractured instruments, very large posts, etc).

Bacteria that are locked inside of a tooth often find other ways out via lateral canals or again through the apex after chronically challenging the apical filling. Also don’t forget about the porosity of dentinal tubules.

The absolute best way to manage a failing endo is to retreat and do surgery, but most of the time this is overkill.

Why retreat and surgery? Because endodontic treatment or retreatment best instruments and disinfects areas coronal to the apical 1/3. Any bacteria left behind at the apex are then taken care of with an apical resection.

This is an important topic in endodontics and I’ve tried to make my answer as brief as possible, but prognosis is a huge part of any endo programme and yet there are no clear answers. Every endo grad comes out of their individual program with a certain bias for or against surgery (versus retreatment).

I think I need to expound a bit on some generalizations that I made in my attempt to be brief. Apical surgery with a retrofill is designed to trap bacteria inside a tooth, however apical endodontic surgery itself can consist of one or two procedures: Apical resection with or without retrofill. The apical resection prepares a root end for a retrofill but does provide the added bonus of removing potentially the largest reservoir for bacteria within the root (the apical aspect). There are also the largest number of accessory canals in this area.

If the practitioner suspects that the problem they are treating (usually bacterial contamination) is limited to the root end (as might be the case with an apically broken instrument in a previously infected root), an apical resection without retrofill should suffice to solve the problem if the entire instrument fragment is removed with the root end. No attempt to trap bacteria inside the canal is done here because the assumption is that there aren’t any above the level of the broken instrument.

The more common reason for apical surgery, however, is when retreatment is deemed risky for a tooth, such as in cases with huge posts. Bacteria are often trapped throughout the canal in these cases. Apical resection without retrofill will not solve the problem because bacteria will still be able to leak out of the apex. A retrofilling helps to minimise this.

So you’re right, surgery is done because the practioner feels that retreatment isn’t possible or a viable option. But you need to remember why the retreatment is needed in the first place.

Oh, I almost forgot. There’s also apical surgery where you can do a retrograde retreatment. You resect the root end and do canal instrumentation from that direction. This surgery is not done often because it’s tough to gain that kind of canal access from that direction. I don’t know the prognosis of this type of apical surgery…

Ian: A root fracture would produce a more periradicular lesion, if this lesion is from a root defect it would be a perforation from the post. There was also no clinical probing — which helps to rule out the possibility of a fracture. The lateral root lesion probably doesn’t show up on the post op film because of minor angulation differences and the fact that it became part of the overall osteotomy. That lesion was because of the lateral canal. As I said in the post, the retrofilling is MTA. I don’t know if I still have any EBA in the office. MTA sets much better in a wet environment than any other filling material. I think this was mentioned to you on the Endo Blog…

fragile: I’d much rather meet people outside of the office than in.

person: Your blog would save you time having to type the same long life updates to each of your friends. Instead you could do a post and facebook can pick it up as a note. I know I like to read my facebook friends’ notes and blogs. Maybe I’m too nosy but a blog is more personal experience than I find facebook to be these days.

live? Yeah, we live in the boonies. I didn’t say that I want to meet people, just that if I had to I’d rather outside of work.

You don’t know scared until you actually see my ugly mug.

I hope the picture took your mind off that racist Tech guy for a second or two. Your gravatar is underexposed also BTW.