Re-Apicoectomy.

Occasionally, we see cases that have had previous treatment, retreatment, and apicoectomy, often times many decades ago, and now require intervention.  The prognosis on these cases is often guarded at best, and it is great that we have dental implants as an option.  If a tooth has a fractured root or is in poor restorative or periodontal condition, I generally recommend a dental implant.

However, there are some select cases, and select patients, where there are some alternatives.  I have a few such cases where I have elected to retreat a case with previous apicoectomy, and have had success without redoing the apicoectomy.  This is usually necessary where the entire canal system or chamber is contaminated, or there are missed canals that can be addressed.  In fact, a missed canals, or a leaking restoration are the most common reasons for apicoectomy failure.  I will save those cases for a future post, and instead show a couple cases where it was decided to "re-apico" the tooth.

This first patient suffered a traumatic sports injury 30 years ago to her anterior teeth.  The original root canal treatment was done at that time.  The teeth had apicoectomies within a few years.  The crowns on the teeth were recently redone, and a sinus tract was noticed soon after.  As an aside, the appearance of apical pathology on a previously treated tooth only following a new restoration is a common trend.  The most likely explanation is a lack of proper isolation during restorative care and a lack of seal in an old root canal treatment.  

There was heavy amalgam tatooing of the buccal mucosa, but the patient was happy with the esthetics of her new crowns after many years of having crowns she considered ugly.  I discussed treatment options at length, and ultimately referred her to a periodontist for implant consult and to learn about the alternative treatment.  After discussing the option of implants with her periodontist, she came back to me to take a chance on redoing the apicoectomy.  The sinus tract was only associated with #9, but upon access, a granuloma perforating the B plate of #8 was noted, and a decision was made to treat both teeth.

Preop #9

Preop #8

Intraoperative, note the extreme bevels already present.
A submarginal scalloped rectangular flap was selected due to an abundance of attached gingiva.  (pic is flipped)

Post op.  MTA retrofil.

1 month recall, no sinus tract.

The 6 month recall will be coming up soon.  

Case Two is similar and more recent.  This was an extremely challenging case.

This patient presented with two sinus tracts, each tracing to #9 and #10.  The crowns on 8-9 and 10 were all recently redone within the past three months.  The post on #9 is out the end, and crown to root ratio is poor.  I recommended ideally extracting #9.  A case could be made to retreat #10, and that would be my usual preference.  The patient understandably was averse to extracting #9, and so an alternate plan of apicoectomy of both #9 and #10 was suggested.  Tooth #9 was already splinted to #8, so mobility is unlikely.  I likened the desired final result to a cantilever bridge, with a little bit of support.  I cautioned the patient that the prognosis was guarded at best, and the patient again wished to proceed with treatment.  

Preop radiograph.

Dual sinus tract tracing.

Upon access, a complete lack of buccal cortical plate on #9 was noted, and is obviously not ideal.  (pic is flipped)
  A papilla-base preservation flap was selected due to a lack of attached gingiva for a  submarginal.
Hemostasis was a major challenge with this patient.

I was able to resect some of the post, retroprep the GP on the palatal aspect of it, and pack it with MTA.
(flipped pic)  I also apologize, the color balance is off on some of these last few photos.

The MTA retrofil on #10. (flipped pic)

Closure with interrupted sutures. (flipped pic)

Post op radiograph.

I was very pleased with the final result of this case.  Only time will tell if we can have sustained success.  I'll be recalling this case is the coming months.

These two cases turned out as well as I could have expected, but I always appreciate any feedback. I always have more to learn about endodontic surgery, since my preferred approach is retreatment for an overwhelming majority of cases, and I don't have some of the experience in surgery that some other clinicians have.  If you would have selected a different flap design, let me know! I'm open to suggestions.

Both cases posted here could certainly have been treatment planned as dental implants.  However, both patients were in the unique situation of very recently having invested in new crowns.  With careful patient selection and expectation management, I believe we can offer patients these types of treatments to preserve their natural teeth, even if for only for a few more years.  

For more unique cases and content, check out our facebook page, www.facebook.com/alpharettaendo.

Root Canal Treatment Can Save Teeth with Cracks

The following case is an example of the successful root canal treatment of a cracked tooth. Tooth #19 was diagnosed as necrotic pulp with acute apical abscess. RCT was recommended to save the tooth.

There was a large 10mm buccal probing depth, however, since the tooth was diagnosed as necrotic, this deep pocket is assumed to be endodontic rather than a true perio defect.

During treatment, a crack is found on the distal under the resin. Using a microscope, the extent of the crack is evaluated. In this particular case, the crack extended to the level of the pulpal floor. This is an important part of the evaluation of a crack, and in my opinion, can really only be done with a microscope. A crack that goes into the furcation or down into the attachment below has a poorer prognosis. Pt is informed the the crack and the potential effect on the long term prognosis of the tooth. Pt is given the choice to continue RCT and save the tooth or extract.

PreOp Film

PostOp Film

1 Year Recall

Bone has healed completely, tooth is fully functional and asymptomatic. This is successful endodontic therapy on a tooth with a crack above the crestal bone.

For more information regarding managing a teeth with a cracks, click here.

Root Canal Retreatment or Implant?

Stan, a recent reader of the blog, commented, "I'm 66 and have an abscessed pre-molar that had rct and a cap 25 years ago. Went to my dentist (who does implants) and was told rct retreatment had a 50% failure rate and the implant-cap was my best option. I had agreed and he injected anesthetic. 15 minutes later, prior to the extraction I commented on the amount of $$ that had already gone into the tooth. Shortly thereafter, after giving me Amoxicillin he said he'd do the extraction in a week. Then on my way out I learned the implant-cap would be a $2700 cost out of my pocket! I'm guessing even he felt that $4K for one tooth is a little much."

About 9 years ago I attended an implant seminar where the lecturer told the audience, "endodontic surgery is only successful about half of the time. So if endodontic surgery is being considered, you should consider extraction and implant". At the time I wondered when they would say retreatment is not successful, so you should place an implant...

3 weeks ago, the following patient presented to our office at Superstition Springs Endodontics.

This 41 year old male patient came to our office for a second opinion regarding an implant. In 5th grade he had trauma to his front tooth #9. He had root canal treatment at that time and has never had a problem until 3 months ago.

The discoloration of #9 is very obvious, however, it has never really bothered the patient.

Not a surprising root canal on a 5th grader. The apex is open, root is short, and the clincian probably did the best he could to obturate this tooth on such a young patient. Please note the normal bone and gingival tissues around the tooth. So this root canal has survived 30 years without symptoms and preserved the periodontium.

3 months ago, the tooth flared up for the first time. He had pain and swelling while on a business trip. He consulted with his general dentist regarding the issue and was presented the options:

1. Retreat RCT - which will probably not work

2. Extract & Implant - This was treatment recommended by his dentist

The patient was concerned about the cost and loss of a tooth which had given him so little problem for so many years. He sought out another general dentist for a second opinion. The next dentist sent him to our office for consultation.

Our diagnosis was: Prior RCT w/ Asymptomatic Apical Periodontitis. The tooth was currently symptom free, but had slight mobility and an obvious apical lucency.

We discussed options of:

1. Retreat RCT - confident we could improve the prior fill, we also discussed the shortness of the root and the mobility issue. We would expect apical lesion to heal, which might help with mobility, but the shortness of the root is still a factor. Nevertheless, its still the same length root he has been using for the last 30 years...

2. Extract & Implant - This is an option, but you may want to consider the short term and long term esthetic issues associated with this implant. Short-term esthetic issues would be making a single implant match the adjacent natural teeth. Long term esthetic issue would be loss of crestal bone over time.

We recommended saving the tooth.

Retreatment elected. The old, poorly condensed gutta percha was removed.

Because of the open apex, MTA was selected as the obturation material. Coronal barrier placed to allow for internal bleaching.

After course of antibiotics and bleaching treatment, the tooth is asymptomatic, less mobile and fully functional again.

I can't imagine anyone arguing that an extraction an implant is a better approach for this patient, but unfortunately there are some with that opinion. I think this may be partly due to a misinformed view of endodontic retreatment. In this particular case, you can see that the original RCT, which lasted only 30 years, without any crestal bone loss was a porous obturation. With normal probing depths and no signs of fracture, retreatment is obviously the best choice. If there are any of you with differing opinions, please share them with us.

UPDATE: 6 month recall of this tooth shows complete periapical healing. Patient reports no symptoms and full function.

In an effort to help all of us understand the treatment outcomes associated with endodontic retreatment and to properly inform our patients regarding endodontic retreatment, I hope you find this information useful.

As explained previously, the historical endodontic literature has reported the success of endodontic retreatment ranging from 100% to as low as 40%. (1) Of course with a range of data like this, you can pick out a study to support whatever argument you want to make! With a paradigm shift towards evidence based medicine and dentistry came the desire to identify the best available evidence with which to make clinical decisions. In a 2004 article by Paik et. al., it was shown that of the published endodontic literature since 1970, there were very few high level studies that had been published on endodontic retreatment. (1)

A study by Torabinejad et al. (2) in 2008 did a systematic review of research from 1970 to 2008 which reviewed outcomes date for surgical treatment as well as non-surgical retreatment in an effort to compare the two treatment modalities. Studies reviewed had to meet a certain criteria for inclusion and were rated for the quality of the study. This included details such as study type, number of patients, experience of clinician, use of magnification, materials used, age of patients etc. An interesting point was there were 3 times as many studies for endodontic surgery that met the inclusion criteria as there were for non-surgical retreatment. This review reported that the overall weighted success rate for nonsurgical retreatment was 78%. (2)

Another well-known outcome assessment study is known as the Toronto Study (3). Their evaluation of endodontic retreatment included 523 teeth on 444 patients. Of the 34% of patients who were able to be recalled at 4-6 years, 81% were considered "healed". "Healed" being defined as absence of apical periodontitis, signs or symptoms. This study points out that patients who did not have apical periodontitis PRIOR to retreatment had the highest "healed" rate at 97%, while those with apical periodontitis prior to retreatment had a "healed" rate at 78%. Another predictor found in this study was perforations. Retreatments done without a perforation had a "healed" rate at 89%, while retreatments with a perforation had a "healed" rate at 43%.

Another retrospective study looking at the success of endodontic treatment (initial RCT and retreatment) performed by a single endodontist in private practice over a 30 year period had similar results. Imura et. al. selected 2000 teeth from a 30 year career for evaluation of success.(4) The success rate for teeth treated with initial endodontic therapy was 94% and the success rate for teeth treated with endodontic retreatment was 85.9%.

In an epidemiological study of 4744 teeth that had been retreated by endodontists in US, participating in Delta Dental Insurance, 89% of teeth were functioning at 5 years. (5)

These articles are just a start. I will try to add more to this body of evidence. Please feel free to suggest any additional articles that should go along with these.

In my opinion, when considering retreatment, consider the quality of the initial treatment. Was it well cleaned and shaped? Are there missed canals? Is the obturation good length? Performed under microscope? Level of expertise of the clinician? If these things can be improved upon with retreatment, then you have a good chance for success with retreatment. I think a fair estimate would be between 80-85% success rate.

We owe it to our patients to give them the option of retreatment. It is not fair to assume a tooth has a 50% success rate with retreatment. If you are concerned about the prognosis with endodontic retreatment, consult with an endodontist. Endodontists are specialists in saving teeth.

REFERENCES

1. Paik, S, Sechrist, C, Torabinejad, M. "Levels of Evidence for the Outcome of Endodontic Retreatment". 2004, JOE 30:11, 745-750.

2. Torabinejad, M, Corr, R, Handysides, R, Shabahand, S. "Outcomes of Nonsurgical Retreatment and Endodontic Surgery: A Systematic Review". 2008, JOE 35:7, p930-937.

3. Farzaneh, M, Abitbol, S, Friedman, S. "Treatment Outcome in Endodontics: The Toronto Study. Phases I and II: Orthograde Retreatment". 2004, JOE 30:9, p627-633.

4. Imura, N, Pinheiro, E, Gomes, B, Zaia, A, Ferraz, C, Souza-Filho, F. "The Outcome of Endodontic Treatment: A Retrospective Study of 2000 Cases Performed by a Specialist". 2007, JOE 33:11, p1278-1282.

5. Salehrabi, R, Rotstein, I. "Epidemiologic Evaluation of the Outcomes of Orthograde Endodontic Retreatment". 2010, JOE 36:5, p790-792.

• 
  

Osteonecrosis and Ischemia in the Alveolar Bones

At a recent seminar, Dr. Jerry Bouquot, the director of diagnostic services at University of Texas, Houston - School of Dentistry, and world reknown oral pathologist and specialist in bone pathology, discussed osteonecrosis of the alveolar bone and issues with ischemia in bone.

The recent issues with bisphosphonate induced osteonecrosis of the jaw bones and well known complications with osteoradionecrosis, demonstrate the severe complications that can occur with ischemia in bone. Dr. Bouquot shared some of his ideas regarding possible sources/causes of ischemia in bone.

The follow video clip highlights the differences between alveolar bone and regular skeletal bone. According to Dr. Bouquot, these differences make the alveolar bone more susceptible to ischemic bone pathology.

Finding Missed Canals Using Cone Beam Computed Tomography (CBCT)

We have had lots of discussion regarding the use of CBCT in endodontic diagnosis and treatment planning. CBCT is the future of endodontics. 3D imaging as an adjunct to 2D imaging is superior to 2D imaging alone. The ability to evaluate a tooth in a sagittal and axial plane (in additional to the traditional coronal view of standard radiographs) provides valuable information that will lead to the preservation of teeth by improved endodontic treatment, endodontic retreatment and endodontic surgery.

There will be many who think this statement is over the top. However, I would compare the advent of focus-field, high resolution CBCT to the introduction of the operating microscope in endodontics. While there was initial resistance to adoption of the microscope, and still some continued resistance by a few in our specialty, the microscope has undoubtedly improved the quality of endodontic care. CBCT is the same. There will be some who argue that they don't need it, however, it undoubtedly will improve the quality of endodontic care and help preserve teeth.

As an example of the benefits of CBCT in improving endodontic diagnostics and treatment, I present the follow 4 cases. Each case completed by a different endodontist. All of these clinicians are highly skilled endodontists using microscopes. However, in each case, canals were missed and the patient continued to have issues. They have different stories, but all ended up in our office for an evaluation or second opinion. I have included myself as one of these 4 endodontists. (One of the cases is my own)

CASE #1

#31 is the symptomatic tooth. Two canals have been filled to a good length.

CBCT slice of mesial root shows the two mesial canals join and exit at one apex.

This is another slice of mesial roots showing the buccal filling and the ML missed canal. The sagittal view tells us where to look when we retreat this tooth. Axial view also demonstrates the missed canal. Using these two views, when I retreat this tooth, I will know where to explore without perforating the root.

This particular endodontist refunded the patient and preferred that we retreat the tooth at our office.

CASE #2

This root canal was treated by another endodontist and then retreated after symptoms failed to resolve. She came to Superstition Springs Endodontics for a second opinion. The obturated roots look filled to an ideal length.

CBCT reveals a missed MB#2 canal. Blue outline shows an axial slice of the MB root. The pear-shaped root outline reveals the missed canal.

The sagittal view also shows the MB#1 canal is off center of the long axis of the root. A lesion into the sinus cavity is noted. Note the distinct MB lesion visible in the CBCT. I explained to the patient that it would be the other endodontist would likely retreat this tooth at no charge, but this patient has elected to retreat the tooth in our office.

CASE #3

This root canal done in 2007. Recently became symptomatic.

CBCT shows lesion on MB and DB with elevation of floor of sinus. This corresponds to chronic sinus issue patient has been dealing with.

Cross sectional slice (axial) through the MB root shows the missed MB#2 canal. The pear-shaped or figure-8 shape of the MB root reveals the missed MB#2 canal.

This sagittal view shows that the missed MB#2 canal is actually a separate root. While the roots are fused all the way down, it has its own apex.

The CBCT is a map for retreatment. It tells us exactly where to look to find the missing canal.

This patient returned to her previous endodontist for retreatment.

I know each one of these endodontists, and they all do excellent work. I confidently suggested to each of these patients that they return to their previous endodontist for evaluation. Using the CBCT map for retreatment, I am confident each one of these endodontists will find the additional canal. One endodontist is retreating at no charge, one endodontist is refunding patient and she will have treatment in our office, and the third patient did not want to return and has elected to pay for retreatment in our office.

CASE #4 - My Missed Canal Found with CBCT

I completed this RCT in Nov 2011. Palatal lesion seemed to improve, but patient symptoms returned. In this particular case, I found only 2 canals. After extensive searching under the microscope, I determined that this must be one of those tricky 2 rooted Mx molars. Since symptoms returned, we took CBCT to see if I missed anything.

CBCT reveals that I did miss a DB canal. However, looking closely at the axial view, my assumption that this is a 2 rooted molar was correct. The palatal and DB roots were fused as one. Sagittal view shows the missed DB canal. Axial view shows the missed DB as well. The CBCT is now a map for retreatment.

As explained, the axial and sagittal view provided by CBCT is invaluable. More information provides for better treatment. This post should demonstrate the level of complexity of molar endodontic therapy even with the use of the operating microscope and the benefit of 3D imaging over 2D imaging alone.

Challenging Isolation

Occasionally, as an endodontist, we are referred a patient for a difficult, maybe questionable, save. This patient was 85 years old and was undergoing cancer treatment. He was referred late one afternoon for treatment of #32. The referring dentist had started the root canal treatment earlier in the day and had stopped due to difficulty locating the mesial canals. The patient arrived with his tooth anesthetized and with IRM in the access. Tooth #32 is the distal abutment of a longspan FPD, and the dentist was confident that it could either be saved or a new FPD fabricated and fit.

Upon access, it was immediately clear why the tooth was a challenge for the referring dentist (if being a tilted third molar bridge abutment on an elderly patient wasn't enough). The mesial gingiva had overgrown beneath the FPD and there was still caries everywhere. Both saliva and blood were flooding beneath the rubber dam and into the access.

After cleaning the caries, resecting the gingiva, and controlling the hemmorhage with astringedent, I called the general dentist on his cell phone to have his restorative input. There was minimal supracrestal tooth structure remaining on the mesial, and I questioned the restorability of the tooth. The dentist was dismissive of any alternatives and confidently requested I complete the treatment.

At this point, something needed to be done to maintain a clean dry field. It became clear very quickly that our normal ancillary use of Oraseal calk was not enough. I had my assistant maintain a steady stream of air on the tooth while I inserted size 6 hand files into the two mesial canals, and a size 30 file into the distal canal. I would recommend lubricating the files with vaseline before placing them. I then maintained the air stream while my assistant mixed up a loose batch of IRM. I placed the IRM and compacted it within the access and around the files before trimming back the material that flowed out beneath the crown.

As the IRM set, I moved the files in a circular patterns to prevent them from locking in and to create a funneled pattern of space. Upon setting, I removed the files and was left with perfect pathways. Through these, I did my cleaning, shaping, and obturation.

Here is the final result:

This technique can be applied to any situation in which caries is removed beneath a fixed restoration, and the restoration is to be maintained to hold a rubberdam and act as a temporary.

If you have any questions or clinical tips to share of your own, please post them in the comments below.

Also, if you are new to the blog, you can also see more of my cases on my office's facebook page: www.facebook.com/alpharettaendo

Thank you!

Internal bleaching makes us smile!

This 13 yr old young lady had some trauma to #8 during a softball game. As you can imagine, the discoloration is of significant concern to the patient.

At the time of the exam, tooth #8 is non-responsive to thermal testing, normal to probing and mildly percussion sensitive. DX: Necrotic w/ SAP. RCT recommended with internal bleaching for esthetic purposes.

RCT completed under microscope assuring that all internal staining is removed from the pulp horns. A coronal barrier is placed in the cervical portion of the tooth. The purpose of this barrier is to prevent bleach from entering the root, passing through dentinal tubules and causing an inflammatory reaction in the pdl. Bleach (Ultradent - Opalescence Endo) is placed in the pulp chamber with a thin, button cavit temporary. Pt is rescheduled for 1 week.

Pt is excited with the new appearance of her tooth.

Final restoration is placed. Endodontists can be a valuable team member in your cosmetic cases!

Value and Limitations of CBCT in Endodontics-Case Report

For the longest time, I have been skeptical of the ability of the CBCT to detect vertical root fractures. Especially in previously treated teeth, where scatter radiation produces artifacts in the image. There has been research(mostly in vitro) supporting CBCT imaging for detecting fractures(Hassan 2009), and there is no doubt that the technology shows exciting promise for use in our field. This case demonstrates both the value and limitations of this exciting imaging system.

The patient first presented six months ago with new crowns on teeth #30 and #31. His symptoms were described as a spontaneous ache and a soreness to mastication that started with the new crowns and felt localized to #31. Diagnostic testing revealed percussion sensitivity and a lingering dull ache to cold on #31, as well as a mild soreness to bite forces on #30. The original root canal treatment and post on #30 were over 15 years old. A diagnosis of irreversible pulpitis was made for #31 and treatment was completed. The mild bite soreness on #30 was attributed to a heavy occlusion and/or some referred pain from #31. Here is our post op radiograph:

The patient reported an episode of severe spontaneous pain lasting one day in the area that started four days after the first visit for #31 and resolved prior to his second visit. This odd experience certainly raised some alarms for me, but when he returned, a new exam and series of diagnostic tests produced nothing of note.

At three months following treatment, the patient reported continued discomfort to mastication in the region. An exam and diagnostic testing produced some continued bite soreness on #30. A new periapical radiograph revealed a possible missed DB canal:

I also speculated on what appeared to be the early formation of a lateral radiolucency on the mesial root that could be the result of a vertical fracture:

However, there were no significant probing depths, only mild symptoms, and no obvious signs of an apical radiolucency. At this point, to aid in our diagnosis, I recommended a CBCT. I reviewed the scan at length individually, and with a periodontist and with an expert from the company. I immediately confirmed the missed DB canal, but also noticed an obvious radiolucency associated with the distal root. What we could not find, independantly or together, was any sign of a fracture in the mesial root or of any lateral bone loss along the root.

It's remarkable the accuracy with which we can pick up the missed DB canal and see the periapical radiolucency (PARL) that was not evident on the periapical radiographs above.

With the new diagnostic information, the decision was made to retreat #30. Of course, I still warned the patient about the risk of losing the tooth if a fracture is found in the root structure. Upon access, I was greeted with the familiar sight of purulent drainage pulsing up the distal with each heartbeat:

Below you can see the missed DB canal before and after post removal: Unfortunately, upon cleaning up the mesial, two fractures were found leading to the MB canal. One along the mesial wall:Another fracture was found along the MB wall: These large fractures probably form a wedge out of the MB root. Unfortunately, they severely compromise the prognosis of our treatment. I cleaned and disinfected the untreated DB canal before placing calcium hydroxide. I then closed the tooth and recommended extraction to the patient. Because of our diagnostic efforts involving a lengthy consult with clinical and radiographic images, the patient was understanding of his situation and appreciative that every effort was taken to diagnose his problem and save his tooth.

In this case, I had high hopes that the CBCT might confirm my suspicion of lateral bone loss around the mesial root. The CBCT was excellent, as it has been in the past, at confirming missed canals. However, it has still not demonstrated to early detect a vertical root fracture prior to an obvious clinical and periapical radiographic presentation.

If anyone has any questions or input, or has had different experiences with the CBCT. Please share them! Also, check out our office's facebook page at www.facebook.com/alpharettaendo where I post new cases regularly.