This was a regendo case, or at the time almost 10 years ago we revered to these cases as revascularization. This tooth belonged to a young Asian girl who had a dens invaginatus. We also had to do the contralateral tooth as both became necrotic. She presented very swollen as a result of this infected tooth. We placed a mix of antiobiotic paste in the tooth for two to three weeks. At the second appointment after rinsing out the antibiotic mix, we used a file long with a little EDTA. A collagen matrix was placed, so that it wicked blood above the CEJ. Grey MTA was placed as a barrier above the collagen, and then the tooth was restored with composite. Axial root development occurs although not much at the level of the CEJ. At the time there was hope that regenerative endodontics could continue root development leading to stronger teeth that could last longer.
The forces of anterior teeth are different than posterior teeth. As such, structural failures often result in “snap off” failures at or about the level of the CEJ. Axial dentin in this area or as Clark and Khademi define pericervical dentin (PCD), is the predominant structure that defends against this type of force and prevents snap off failures. My good friend and co-resident David Prusikowski won a prize for a revascularization poster where the management was applied to an anterior tooth. Unfortunately for the patient and the subject and poster, the tooth snapped off not long after the prize was awarded. The mix of hard tissue is somewhat unpredictable, and while some root lengthening, or some apical development may occur, it is very rare to find cases where PCD was increased in any real way.
This is an interesting case where I learned a few things. The patient presented with swelling and had a history of trauma. Given the development of the tooth we opted to try a regenerative approach to build some dentin strength and add for some longevity. At the time the patient requested her restorative dentist place the filling and we obliged. In this case we used calcium hydroxide instead of the bimix as the recommendations had changed. We still used collagen and MTA though. The tooth was restored by her dentist. After 4 years we can see some apexification. However, no PCD acquisition was evident.
The patient returned with symptoms of acute percussive pain on the tooth. I thought it odd as there was boney infiltrate throughout the canal. Regardless it was prominent and repeatable. Additionally, staining of the MTA was observed. So we decided on a revision. A significant void was noted over the MTA on re-entry. After the MTA was removed, bone was observed just below the level of the MTA, at the level of the CEJ. Calcium hydroxide was expressed into the canal amongst the bone infiltrate. Over several appointments, the bone was removed by devitalizing it with calcium hydroxide, ultrasonics, and small burs. The tooth was also bleached to remove the MTA staining.
Eventually we were ready to obturate, and grey MTA was placed apically.
We inverted a fiber post which we bonded in with a dual cure buildup material and placed a few accessory posts. We trimmed back the posts and provided a “Clark cala lilly preparation” which creates long bevels in enamel before restoring with composite.
So, in considering the number of these types of cases that I’ve done over the years as well as how anterior teeth most often fail, I think taking the benefit of fiber post reinforcement is often preferable to revascularization as the regendo cases don’t predictably create PCD. There are a few cases types though, perhaps with really divergent apices where it may be the only choice. But by the time most of these teeth hit the mouth, they have enough development that tilt the decision in favor of fiber reinforcement.
Great post Mike! Thank you making me a better clinician. I count you amongst a handful of people who have fixed how I do dentistry! The commonly held belief that the purpose of a post is to retain a core is only partially true as you know. I’ve come to realize (the hard way) that the use of a post(s) as you have done in the revision treatment is more important for the long term outcome of these case types.