Regenerative Endodontics - Another Case Report

Regenerative endodontics is the application of tissue engineering concepts into the treatment of the pulp-dentin complex. We all know that the pulp has regenerative/healing properties. We routinely tell our patients that the restorative treatments that we do will cause inflammation/irritation to the pulp. Occasionally, we even encroach upon the pulpal space and then medicate the pulp in an effort promote pulpal healing and repair. The formation of reparative dentin is evidence of the pulp's ability to regenerate/repair dentinal tissues.


Regenerative endodontics is currently in its infancy. However, the possibilities are exciting and the research is ongoing. Regenerative dental therapies may one day lead to more effective vital pulp therapy, more effective treatment of immature teeth, traumatized teeth, and possibly the replace of missing teeth with bioengineered teeth.


Current clinical success in regenerative endodontics is seen in the treatment of necrotic, immature teeth with apical periodontitis.


The following case, treated at Superstition Spring Endodontics, has shown ideal pulpal regeneration allowing for the continued development of an immature root.

A necrotic tooth #29, with a large periapical lesion, and wide open apex is selected for regenerative endodontic therapy. The canal accessed and the pulp completely removed to the apex with minimal filing and copious NaOCl irrigation.

A coronal MTA plug is placed to prevent coronal leakage, while the apical portion of the tooth is left wide open for regeneration.

At 3 months, the large apical lesion has healed.

At 6 months, the apex is thickening and lengthening.

At 6 years, the canal has closed, root has lengthened, and the tooth is now responding to electric pulp testing.


This procedure has allowed this patient to retain a tooth that otherwise may have been lost.


The future of regenerative endodontics is bright and exciting.

Regenerative Endodontics - New Frontiers in Endodontics

Regenerative endodontics is an exciting new concept that seeks to apply the advances in tissue engineering to the regeneration of the pulp-dentin complex. Multiple case reports have shown the ability for previously necrotic, immature teeth to "regenerate" pulp-like tissue allowing for continued development of the tooth.

Traditionally, when an immature tooth became necrotic, root development was arrested and the endodontic goal was to create some kind of calcific barrier against which we could obturate. This is known as Ca(OH)2 apexification. The downside to this treatment was length of treatment time and weak, short, thin roots that remained.

More recently, MTA apexification has become more common. This consists of debridement of the immature root and immediate obturation with MTA. This shortened the treatment time, but the problem of short, thin roots still remained.

Multiple case reports, including cases at Superstition Springs Endodontics, have shown the ability to remove the necrotic tissue and stimulate regeneration of pulpal-like tissue into the canal. This allows for the continued growth of the immature root. The dentinal walls thicken, the length of root increases, periapical lesions heal and the open apex closes.

This is a completely new way of approaching apexification and provides a glimpse at exciting new horizons in endodontics and tissue engineering. I was recently asked by a colleague if I had interest in placing implants. I explained to him that while implants provide a valuable service to replace missing teeth, as an endodontist, I am dedicated to preserving the natural tooth. I am grateful to work with so many great implant surgeons, but I expect there will come a day when real teeth are replaced with real, bioengineered teeth.

Here is an example of pulpal regeneration performed at Superstition Springs Endodontics.

This young patient had tooth #8 avulsed. The tooth was stored in milk <1hr>

Tooth #8 was accessed, pulpal tissue removed with minimal filing and copious NaOCl irrigation.

Coronal MTA plug placed w/ cotton & resin access filling.

At 2 months, the periapical lesion is gone and tooth is asymptomatic.

At 4 year recall, the apex has closed, the dentinal walls of the root have thickened and the tooth is asymptomatic and functional.

The protocol for this procedure is still being developed. The American Association of Endodontists is building a database regenerative cases to aid in the development of this protocol.

The upcoming Inner Space Seminar entitled, "It's Alive! Pulpal Regeneration" will review concepts in stem cell therapy, current accepted treatment protocol for pulpal regeneration and additional case reports of pulpal regeneration.

Indications for Intentional Replantation

Intentional replantation is the intentional removal of a tooth and replantion into the socket following endodontic manipulation.

Success with this treatment is dependent upon atraumatic extraction, minimal manipulation of the periodontal ligament, rapid replacement into the socket, and minimizing occlusal forces following replantation.

While endodontic apical surgery (apicoecotomy) is the most common type of endodontic surgery performed, intentional replantation is an option when apical surgery is not indicated due to anatomical considerations. These may include: proximity to the mental foramen or mandibular canal, thickness of Md buccal bone along oblique line angle, and proximity to Mx sinuses.

I have found intention replantation useful in the following clinical situations:

Cases where endodontic surgery is not an option due to difficult anatomy...

1. Md 2nd Molars - access through buccal bone difficult
2. Md 1st & 2nd Bicuspids - closeness to the mental foramen
3. Mx 2nd Molars - access difficult & sinus complications likely

Cases where conventional retreatment has been unsuccessful or not likely to be successful

1. Cases with ledging and/or separated instruments
2. Retreatment has been attempted without success

Other factors to consider...

The root anatomy has to allow an atraumatic extraction to occur. Conical shaped roots are most ideal.

Intentional replantation provides a treatment option when tooth replacement with an implant or bridge is not feasible.

These patients have already had endodontic therapy, and crowns placed. Costs associated with this additional treatment are minimal compared to cost of tooth replacement.

The following cases demonstrate intentional replantation.

CASE #1

RCT was completed and patient continued to have apical pain. Extrusion of sealer was assumed to be the cause of the apical periodontitis. Close proximity to the mental foramen makes apical surgery contraindicated.

Following atraumatic extraction, the gross overextension of gutta percha is obvious. Apical resection and burnishing of gutta percha completed within minutes.

Tooth replanted and treatment completed.

CASE #2

Initial RCT completed.

Sinus tract persists.


Non-surgical retx completed and symptoms persist. Discussion with patient of options:
1. Extraction
2. Replantation
Pt understood options and selected intentional replantation.

Atraumatic extraction, immediate resection.

Replantation completed.

3 month recall. Tooth asymptomatic and completely functional.

Sources:
Pathways of Pulp, 9th edition - online version. p767-768.

Is That a Root Fracture?

Large J-shaped lesions are often associated with vertical root fractures. This tooth was asymptomatic to percussion, non responsive to thermal testing and surprisingly normal to probing. Diagnosis: necrotic pulp and asymptomatic apical periodontitis. It was was determined to be an endodontic problem.

The large radiolucency extends up the distal root into the furcation. Microscopic examination during endodontic therapy revealed no root fracture. In this case, the assumption of a root fracture, based on radiographs alone, would have been incorrect.

Without proper diagnosis, this tooth might easily be labeled a fractured root and extracted. A new crown is indicated to prevent coronal leakage.

Root Canal Treatment Saves a Perforated Tooth

This root canal was started in July '09. After having difficulty finding the canals, the tooth was referred to our office.

Upon opening the tooth, we found a supraboney perforation on the ML surface.

Canals were located using a operating microscope and the root canal completed.

The ML perforation was repaired using Geristore. (Since this perforation was above the crestal bone, a restorative material that would not wash out must be used. MTA is not the best material in this type of perforation)

A six month recall finds the lesions almost completely healed and the tooth pain free and functional.

Calcium Hydroxide as Intercanal Medicament

Ca(OH)2 pastes are used in endodontics as a temporary canal filling material for multiple purposes including:
1. Stimulate continue root development
2. Control exudate/disinfect the canal system
3. Prevention of external root resorption following traumatic injuries
4. Create an apical barrier following over instrumentation

Occasionally, I will use calcium hydroxide as a intracanal medicament to look for signs of initial healing prior to obturation. On this particular retreatment case, the distal canal was long and wide. I was concerned there may have been some resorption or possible an apical crack that I could not visualize.

Pre-Operative Radiograph

Calcium Hydroxide paste was placed (and extruded) in the canals.

3 month recall shows remarkable resorption of the extruded Ca(OH)2 and healing of the apical lesion.

Tooth was re-obturated and another tooth has been saved!

Source:
Cohen & Burns. Pathways of Pulp 6th ed. p.406-407.

Herodontics? - Revisited

In Aug 2009, an American Academy of Implant Dentistry press release stated, "...times have changed and patients should forego prolonged dental heroics to save failing teeth and replace them with long-lasting dental implants". While it universally accepted that implants are a great way to replace missing teeth, a more controversial topic is when to replace a diseased tooth with an implant. In my opinion, those promoting dental implants have become increasingly more aggressive about replacing natural teeth.

As a specialist, I am occasionally called upon to perform "heroic" procedures. This may be following some iatrogenic damage or by a patient who wishes to retain a natural tooth at any cost. While I would much rather treat a normal, straightforward endodontic case, the use of microscopes, ultrasonics and MTA have allowed us to preserve teeth that many would consider "hopeless". I am often amazed at the success that we have with some of these "heroic" cases.

The following case was previously posted, but the patient returned for a 4 year recall last month. Unfortunately, the patient was returning for another root repair perforation following endodontic access on a different tooth. This case would be considered a "heroic" case by anyone's standard! In this particular case, this patient has been pleased with his decision to retain the tooth.

Original Post
This root canal was done just over four years ago. The patient presented with pain to percussion, and an 8 mm buccal probing was present. The RCT had been completed 2 years previously and recently became symptomatic.
DX: Prior RCT w/ Symptomatic Apical Periodontitis.
Treatment recommended: Non-surgical retreatment, perforation repair with possible need for endodontic surgery. Prognosis: guarded.

As you can see, the MB canal is very calcified. Calcification of this kind would make this case a very high level of difficulty. The MB canal was missed and the furcation was found, instrumented & obturated. Proper case selection can help prevent this type of complication. However, if this does occur, one would expect to find bleeding and the tactile sensation of the pdl/cortical bone is very different from the canal. Length determination films, working films or final films should also identify the perforation. I would recommend immediate referral to an endodontist for treatment of an iatrogenic event such as this.

Retreatment completed. MB canal located and treated. Furcal perforation repaired with MTA. Patient placed on recall to watch the area and see if endodontic surgery will be required.

Recall at 2 years & 3 months. Patient reports complete function and no symptoms. The 8mm periodontal probing has dissappeared. This tooth is considered "healing", and scheduled for a 1 year recall.

You can call it "herodontics", but that tooth is functional, apical bone looks good, periodontal pocket has disappeared. This will be a fun case to watch over time.

4 Year Recall

Asymptomatic & fully functional.

NOTE: I have never said this is pretty. Actually, its pretty ugly. However, retaining the natural tooth has preserved the crestal bone, provided normal function, and cost much less in time and money than any replacement option available.

Retreatment & MTA Save a Perforated Tooth

The following case was submitted by Dr. Rico D. Short of Smyrna, GA.

Original endodontic treatment was done 15 years ago. The crowns on 8 & 9 were replaced 2 years earlier at which time the dentist placed post for retention. During post preparation, the root was perforated. A large lesion has developed.


DX: Prior RCT w/ Chronic Apical Abscess w/ root perforation. Pt was informed the prognosis was questionable due to the perforation. Pt understood and consented for treatment including perforation repair.

Retreatment on #8 completed with MTA root repair.

8 month recall

22 month recall finds patient asymptomatic and functioning with no mobility and normal probing depths.

While many clinicians would have deemed this tooth "hopeless" and recommended extraction, MTA, microscopes and a expert clinician can save teeth that otherwise would be extracted.

Endodontic Retreatment & MTA Preserve the Tooth

Here's a tooth that had endodontic treatment over 10 years ago. While the clinician had difficulty finding all the canals, the tooth has been functional for quite some time. A large furcal defect raises suspicion of a root fracture or perforation.

DX: Prior RCT w/ Symptomatic Apical Periodontitis.

There are many who would consider this hopeless and recommend extraction.

Let us consider the cause of this treatment failure:

1. Missed Canals

2. Furcal Perforation or Root Fracture?

Can these issues be addressed to preserve the natural tooth?

In my consultation with the patient, I explain these issues and that endodontic re-treatment may be able to save the tooth (as long as the root is not fractured). I also explain the alternative option of extraction.

Finding missing canals is a simple solution.

A perforated root can be repaired with guarded prognosis.

A fractured root will require extraction.

I tell the patient the only way to know for sure is to open the tooth and investigate. Considering the nice crown on the tooth, the cost of attempting to save the tooth is minimal, compared to the cost of removing and replacing. In this case the patient elected re-treatment.

Pre-operative radiograph.

Upon access, 2 additional canals are located and instrumented. A furcal perforation is also identified. No root fractures are found.

Re-treatment is complete. Canals obturated with gutta percha and furcal perforation repaired with MTA. Glass ionomer base is placed over MTA.

7 month recall shows a tooth that is fully functional with remarkable healing of the furcal defect. Endodontic re-treatment has preserved the natural tooth.

Dens in Dente

Dens in Dente literally means "a tooth within a tooth". It is a developmental anomaly caused by an epithelial invagination during the development of the tooth. Enamel is laid down on the internal surface of the tooth. This is most frequently seen in maxillary lateral incisors.

A thin layer of enamel can be seen internally. An amalgam restoration was previously placed at some point to try and seal off the development groove into the dens in dente.

Access for endodontic treatment reveals the internal layer of enamel.

Endodontic treatment is completed.


This peg lateral incisor also shows the internal and external layers of enamel of a dens in dente. The large dens in dente has also affected the overall development of the tooth.
Submitted by: Dr. Rico D. Short of Smyrna, GA.