The Endo Fix

Category: Weekly Fix

Decoronation of an Ankylosed Tooth

Weekly Fix

Decisions…decisions. A very young looking 10 year old girl presented after an avulsion of tooth number 9 with a very short extra-oral dry time, immediately replanted and subsequently splinted. The decision of whether to initiate endo on the central is dictated by the time out of the mouth and the development of the tooth. I made the call that the apex looked wide open and the tooth hadn’t completely developed. So we decided to wait and see if the tooth would revascularize. My first follow-up time of trauma is typically 3 weeks. I saw her inside of 4 and resorption was already full on; progressive and aggressive. Classification wise this would be external axial resorption. We initiated endo immediately, but the damage was done. Additionally, the concussed lateral wasn’t responding to cold, so we started endo on that one as well.

We kept the tooth in medication for 5 months changing it out monthly. Over that period of time there was ankylotic tone and no mobility under the scope using 2 mirror handles to evaluate. Ugh. We placed Vitapex in the canal which lasts longer than many other CaOH preparations, and restored. Over time, washing out of the medication could be observed; a common finding in a resorbing root. We waited until we measured 3mm infra-occlusion and set her up for a flapless decoronation like my buddy Buck came up with circa 2008.

If you can, preserve the pulp. If you can’t; save the root and tooth. If you can’t do that, at least save the bone. That’s where decoronation comes in.

We clamped the other central and split dam to the distal of the lateral and used a rubber dam triangle to wedge the dam distally. Then we cut the crown off using a an 014 tapered diamond. Then a surgical length 556 on end, we cut the tooth flat to 1-2mm below the bone. It’s critical to remove all the enamel as it won’t resorb. We observed granulomatous soft tissue extending from the canal space. A good clot was evident before dismissing the patient.

Hindsight being 20/20 I woulda medicated the tooth at a week. Similar patient representing the same way? That’s tougher. I’m thinking if the tooth looks most of the way developed, regardless of the apex developement, I might jump in. It’s a tough call.

Custom Resin Matrix

Weekly Fix
su
Suflolk Endodontist

Terminal teeth are tough to band and keep rubber dam isolation. So we came up with an alternative- the custom resin matrix. Using green opaldam we make a custom matrix to pack amalgam with or place a controlled field resin. Often we use the technique subgingivaly on bone. For first iterations we used white Opaldam but found it hard to discern on bone. The green is easier to see and thus remove. Waiting 5 minutes or so for the amalgam to harden makes the green matrix easier to remove

Root Tip Endo

Weekly Fix

Consider these observations:

Chesapeake Endodontist
Suffolk Endodontist

These are but a few of the many documented cases of root tip endos that I’ve seen over the years in practice. The patients are all asymptomatic, albeit clearly not functional. We can see food, plaque, and caries sitting on the root filling. These roots have been infected for years. If we were to say that there was some sort of threshhold of bacteria that need to be removed to have a favorable endodontic outcome; these teeth would represent the maximum, most bacteria filled, most infected roots possible. And as such these teeth should have both clinical symptoms of pain and swelling as well as radiographic signs of endodontic pathosis. However, all of these patients are asymptomatic. And radiographic interpretation suggests they are typically free of apical findings. How could it be that the most infected roots have no radiographic findings? It must be something more than just the presence of bacteria or some degree of bacteria in the root of the tooth that defines endodontic pathosis.

Perhaps the lack of occlusion on these roots has something to do with it. If this is true, as the available evidence suggests, then occlusal function plays a role in “endodontic pathosis”. Such a supposition isn’t terribly surprising in that occlusal parafunction can lead to endodontic necrosis in the absence of caries. Furthermore, many of the signs and symptoms traditionally associated with infection related endodontic pathosis can be associated with occlusal parafunction even in the absence of infected roots or proximal caries. Thus, the myriad of endodontic conditions that present in clinical practice are not well explained by the apical periodontitis disease model and the relationship between radiographic findings and endodontic pathosis is not a direct one.

Considering Revascularization, Regendo

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Suffolk Endodontst

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.

Chesapeake Endodontist

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.

 

Hampton Roads Endodontist

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.

Suffolk Endodontist

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.

 

 

Trauma, Resorption, and Decoronation

Resorption, Weekly Fix

Suffolk Endodontist

This little guy caught a fly ball… in the mouth. The lateral was laterally luxated. The central was avulsed and replanted with a dry time of 15 minutes. The lateral was repositioned and splinted. I saw them the day after the injury. We made sure he was on an antibiotic and anti-inflammatory and saw him back in a week to start endodontic therapy as the apex of these teeth were completely deveoloped and the risk of resorption high. After what we thought was a sufficient time in both CaOH and splint therapy, we completed the endodontic therapy and placed fiber posts.

Newport News Endodontist

Over the next few years we saw resorption develop. According to the Resorption Classification for Clinicians, this resorption would be considered External Crestal Resorption, moderate scooping. We removed the invasive tissue and restored the root using composite. A custom resin matrix was used for isolation.

Hampton Roads Endodontist

Over time, we could see that the central was subject to resorption as well; External Ankylotic Resorption. This was evident by the ankylotic tone when percussed. Radiographically, this was evident my the marked lack of periodontal ligament and lack of tooth root definition. Clinically, this was evident by the infraposition of the clinical crown relative to the other central.

Root Canal Expert

In treatment planning the case, the orthodontist thought some initial leveling and aligning using the ankylosed tooth would be helpful before decoronation. After this was accomplished, the fiber post and root filling was removed and the crown was decoronated using the flapless decoronation approach as outlined by Jared Buck in Best Practices: A Desk Reference

Chesapeake Endodontist

A pontic was added to the orthodontic therapy.

Harbor View Endodontist

We can see over time that bone developed over the tooth root and the the root is turned over in osseous regeneration. The alveolar ridge is preserved for future restorative replacement.

Hampton Roads Endodontist

Here’s the 5 year followup.

Crown Repair

Weekly Fix

Chesapeake Endodontst

Hampton Roads Endodontist

Newport News Endodontist

Newport News Endodontst

Suffolk Endodontist

 

A quality crown repair is important for successful patient centered outcomes. What’s desired is a quality core and an esthetic closure. There are options in achieving these goals, and presented here is just one process. I’ll outline the steps, materials, and rationale. This case was a retreatment from a restorative failure; the core was poorly adapted and the tooth was symptomatic. The patient was highly motivated to prevent this mode of failure on the retreatment. Amalgam as a core has a long track record and because of it’s handling characteristics works will in very conservative accesses where pulp horns have been intentionally preserved.

  1. Chamber Cleanup: After obturation, I like to clean up the obturation interface with a peezo with that little bump cut off. Just zip it off with a football bur.  A #2 works well if your final file is around a Protaper F1 (22.07). If more conservative instrumentation is used, I find the #1 works well. Then alcohol to clean up any remaining sealer, followed by etch. That’s my chamber cleanup protocol.
  2. Bonded Amalgam: At this point you gotta decide if your going to bond your amalgam. The available evidence suggests there are likely benefits, so I do it. Clearfill primer, air dry, then Clearfill bonding agent which is light cured. A second unset bonding agent is placed and the amalgam is condensed into this second top layer of uncured bonding agent. The dual cure nature of this bonding agent creates the bonded amalgam.
  3. Carving the Amalgam: I like a spoon for this. If you want you can get some mechanical retention by undercutting the casting a little. Hard to say if it makes a difference. But I do it on Zirconium crowns.
  4. HF Etch: At this point make sure you have a good bevel using a course football bur. Then hydrofluoric acid is used to etch the porcelaine, this minute feels like forever. Then my assistant suctions the acid and she rinses while I scrub the precipitate off. If you don’t scrub it, the bond won’t be as good. I just use a piece of sponge. Then dry the water off.
  5. Silane: You can use an additive to the Clearfill Primer or just the silane. The silane has a long track record. Newer isn’t always better. The silane needs to be air thinned.
  6. Bonding: Then I place the Clearfill bonding agent over the porcelaine and amalgam.
  7. Opaquer: I like the permaflow flowable composite. It has an opaquer shade that hides the silver really well.
  8. Composite: We use Filtek body- it works well with Clearfill products. My assistant expresses part of a carpule on a mixing pad, then scoops up the composite on the back of a spoon. We use the orange filter so the composite doesn’t set, and apply the first bank of composite. After it’s manipulated in place and cured, we add a couple more increments using an endo explorer or a spoon to shape the composite.
  9. Finish and polish: Usually we don’t need much adjustment. But it’s important to get the occlusion right. A fine football and a zirc polishing point helps on any adjusted parts of the crown.

That’s it! Pretty and predictable.

 

 

Deep Margin Management

Weekly Fix

hampton roads endodontist

Suffolk Endodontist

 

Deep caries and the resulting deep margins can be a restorative problem especially when the patient has a history of interproximal caries or a “high caries hostility index”. Generally speaking it’s better to have a crown that fits and fits on a meticulously placed deep restoration than a crown that doesn’t fit. And when the margin is very deep, then that is when a poorly prepared and poorly captured margin is most likely. An alternative is DME or deep margin elevation. Dentists have unintentionally placed margins on amalgam for decades with success. It’s likely that the outcomes will be even more favorable when done intentionally under controlled circumstances, under magnification and with no overhangs. Attached is a 7 year outcome with the crown placed on amalgam. Also attached are two very long term outcomes. When placing margins on restorative material, it is probably best to choose amalgam over composite as it does not rely on bonding which is poor under such conditions. It’s also advisable to evaluate the emergence profile of the tooth, it’s contact with adjacent teeth, and potential plunger cusps that led to the problem to begin with. Managing these variable can prevent food impaction and decrease the probability of failure to recurrent caries.

Resorption Repair

Resorption, Weekly Fix

Suffolk Endodontist, www.endoviriginia.com

Suffolk Endodontist, www.endovirginia.com

Suffolk Endodontst

Suffolk Endodontist

6 year followup on this case. CBCT imaging was used for determination of restorability. This type of resorption is crestal resorption. The resorption was determined to be less than two line angles by way of extent and located on the palatal. The endodontics was performed and a fiber post placed well below the level of the resorption. In this case we performed a burectomy to remove the ginigiva and visualize the cavosurvace once the the resorptive soft and hard tissues were removed   A matrix band with a little Dycal was used for isiolation. A bulk fill of glass ionomer was placed and then vaneered with flowable composite. The restorative material approached the bone in the area of resorption, however, on followup there is no recession, and no bleeding on probing. We’re cautiously optimistic about a favorable long term outcome.

Management of Pulp Horns

Weekly Fix

suffolk endodontist

Hampton Roads Endodontist

 

Pulp horns recede with age and from pulpal insults resulting from caries, restorations, and trauma. Because of the patient population we care for, many of the teeth we treat as endodontists, don’t have prominent pulp horns. Thus, for the vast majority of our patients, a simple incisal based approach is appropriate for canal management, conservation of tooth structure, and post reinforcement.  However, one subset of our population is trauma. More often, trauma affects younger patients. As a result endodontic management of teeth with pulp horns may be necessary. In this case, the patient was injured playing soccer. The tooth began discoloring and lost sensibility to cold. If the pulp horns aren’t managed, and a conservative approach is used, it’s possible to leave debris and or voids in this area. It’s possible that such a process centered outcome may predispose the tooth to an aesthetic failure if the tooth discolors over time. This is particularly true during apexification procedures if MTA is used and MTA (regardless of whether grey or white is used) ends up in this void. Access along the long axis of the tooth leaves a sharp angle of dentin adjacent to the pulp horn. This transition leads to void formation during the restorative procedure. Adjusting the dentin here with an internal axial groove allows air to vent and restorative materials to proceed without jumping over the sharp transition leaving a void. In order to prepare such a vent, adjusting the enamel in the apical aspect of the access can facilitate the use of small burs and/or ultrasonics. In the more rare situation that a shovel shaped incisor presents with the need to manage pulp horns, the risks and benefits must be carefully weighed if contemplating a buccal approach as a larger more demanding composite restoration may be necessary if the pulp horns are to be managed.

Bypass Express

Weekly Fix

Hampton Roads Endodontics

In evaluating teeth for re-treatment, I usually look at the bitewing first to evaluate the remaining peri-cervical dentin (PCD). Then I adjust my gaze apically to see what’s going on. In evaluating this tooth, it really hadn’t been violated too bad with axial reduction as it had a gold crown, the access didn’t look particularly gauged, and the root canal shaping hadn’t been excessive. So, this tooth has another life. Honestly, I didn’t notice the separated instrument in-bedded in the root. I was able to bypass the instrument in the missed canal and medicate beyond it. We discussed the need for possibility of surgery in the future. We also discussed the risks and benefits of trying to remove the instrument rather than bypass. Lots of times, in an effort to remove an instrument the dentin cost is pretty high. So, we opted to to be content with the bypass. At the 1 year mark, it looks like we’ve got full regeneration apically. One of the clinical applications for CBCT is to evaluate healing at different time intervals.

-Trudeau