In my last blog, I talked about how to go about restoring a posterior tooth after it had been treated endodontically. The consensus in the literature clearly states that when you have a posterior tooth treated by endo, do a full-coverage restoration. No ifs, ands or buts.

However, how should you go about treating an anterior tooth that has had root canal therapy but needs restorative work?

Below is a case that was posted on the forum. It was posted for other reasons; however, what caught my eye was the restoration on #9 with the endo access in the lingual.

So my question is, would you have prepped the same way or would you have done a full-coverage restoration? This comes up quite a bit and the answer may surprise you. As we discussed, in the posterior, we want full coverage. In the anterior, however, do all you can to preserve the cingulum and avoid doing a full coverage. 

In fact, I would have treated this tooth exactly the same way, as two separate restorations. An anterior all-ceramic with a separate composite closing off the endo access.

The weakest area in anterior teeth is the lingual fossa, and this is the area that causes the tooth to flex significantly when it is undergoing excursive movements.

What compensates for the flexing is the cingulum. If you cut the cingulum away, you significantly weaken the tooth. 

To summarize: Posterior teeth, full coverage.  Anterior teeth, partial coverage if a restoration is needed. If this was a virgin tooth, close the access with composite and call it a day.

Good point Sam. Pascal Magne has some excellent stress thermodynamic images illustrating why we should preserve the cingulum when possible. Preserving enamel is also helpful for adhesive dentistry.