The Ins (and Outs) of Saving Teeth

Dr. George Bruder on Root Canal Therapy Advancements, Dentin Preservation and Intentional Replantation

Recent advancements in endodontics allow teeth to be treated more efficiently and with less pain. In fact, an AAE consumer survey found that patients who have experienced a root canal are six times more likely to describe it as painless than those who have not. But root canals haven’t just changed for the patient. Continuing advancements in the field of endodontics are allowing clinicians to see root morphology in ways never seen before, to preserve more dentin and to treat teeth once deemed un-savable, even if it means taking them out in order to put them back in.

Dr. George Bruder, Co-Founder, CFO and Director of Education at the International Dental Institute – Forever Learning, recently performed a case that illustrates how these advancements provide clinicians with better information to make decisions and plan their treatment.

Immediate post-op radiograph of #18 taken in 1999 following root canal therapy.
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Pre-op radiograph of #18 taken in 2015.
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A female patient visited a prosthodontist and colleague of Dr. Bruder’s last year regarding pain in the lower left quadrant of her mouth. Tooth #18 had been previously treated via non-surgical root canal therapy in 1999, making it a logical place to begin investigating the patient’s symptoms. The patient was referred to Dr. Bruder for further examination of tooth #18.

“Upon examination, the patient reported a 10 out of 10 on the pain scale and had lingering pain upon thermal testing,” Dr. Bruder said. “And she was also complaining of a slight change of feeling in her lip.”

A pre-op radiograph of tooth #18 clearly shows evidence of a radiolucency below the apex and that the obturation material had resorbed. However, during the examination, Dr. Bruder determined that the source of the patient’s pain extended beyond tooth #18 to #19. To further investigate, Dr. Bruder took a narrow field of view CBCT scan of the region.

CBCT scan of tooth #18 & #19.
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Looking at the cone beam from the saggital view, Dr. Bruder was able to come to a complete diagnosis. The patient’s acute pain was actually coming from tooth #19, but was complicated by inflammation of the periradicular tissues in #18.

“In the sagittal plane you can clearly see evidence of internal resorption and how large the radiolucency is apical to #18. But after clinical examination and reviewing all imaging of tooth #19, I learned the true source of the patient’s acute pain. There are lesions on both the distal and mesial roots. An equally telling sign that #19 was the source of her acute pain is that she reported lingering pain to thermal testing.”

Dentin Preservation

Given that tooth #19 was the cause of the patient’s acute pain, Dr. Bruder first focused on treating it, but long narrow canals presented a challenge. “Long canals always present added challenges during instrumentation and #19 had long, tight canals in both the mesial and distal roots. And, on the distal root, you see a prominent canal visualized on the CBCT and pre-op radiograph, but it disappears as it descends apically. That’s because it’s actually a type two canal system that comes together as one in the apical third.”

Dr. Bruder felt that #19 presented a perfect case for TRUShape 3D Conforming Files given the canal morphology. “TRUShape allowed me to preserve dentin and reduce the tooth’s overall risk of fracture by decreasing the cumulative loss of tooth structure.”1

After cleaning and shaping, each canal was obturated with TRUShape gutta-percha points using Calamus Dual to burn down and backpack the canals with gutta-percha.

Post-op radiograph of #19 after treatment with TRUShape.
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A post-op radiograph taken after treating #19 more closely reveals the complexity of the anatomy. “You can see the two mesial canals have several lateral canals and the distal root has a type two system merging together in the apical third.”

Following treatment, the patient’s acute pain in #19 was relieved. However, the patient’s pain and lesion in tooth #18 still needed to be addressed. To get a better view of #18, Dr. Bruder again reviewed the CBCT scan previously taken.

In the narrow field of view (FOV) CBCT coronal view, the inferior alveolar nerve is evident. You can also see the size of the lesion and its close proximity to the nerve.”

Once armed with a full picture of the complex issues causing the patients pain, Dr. Bruder established his treatment plan for tooth #18.

Intentional Replantation

As every endodontist knows, the primary purpose of root canal therapy is to save the tooth. That is, to keep it in the patients mouth. So when one of the first steps to accomplishing that involves extracting it, you’ve moved beyond thinking outside the box to thinking outside the mouth. But to save tooth #18, Dr. Bruder needed to do precisely that – extract the tooth to enable removal of the apical resorptive defect and then replant it.

CBCT coronal view of #18 showing the lesion and its proximity to the nerve.
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“Tooth #18 was facing a road-block at every turn. The resorptive defect is much larger than can be seen from a two-dimensional radiograph and the lesion is in close proximity to the inferior alveolar nerve. Because of the thickness of the buccal plate and the close proximity of the lesion to the nerve, an apicoectomy simply wasn’t practical.”

To overcome those obstacles, Dr. Bruder believed the best, and perhaps only, option to save the tooth would be intentional replantation. Thus, the patient was scheduled for a subsequent visit following the nonsurgical treatment of #19 to perform intentional replantation on #18.

Post-op image of #18 & #19 following restoration by the prosthodontist.
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Three month follow-up image of #18 & #19 showing signs of healing.
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To successfully perform the procedure the tooth was carefully extracted without fracture and placed into a surgical bath before resecting the root. The root-end was then prepared and filled with a root-end filling material (ProRoot MTA). The lesion was removed and finally, the tooth was replanted in its socket. After replanting it, sutures were placed to stabilize the tooth temporarily.

A post-op radiograph shows both teeth after restoration by the prosthodontist. Another follow-up radiograph was taken three months following the procedure.

“At my follow-up visit, the patient was completely asymptomatic and tissues were healing beautifully,” Dr. Bruder said.

Root Canals Aren’t What They Used to Be

For Dr. Bruder, it is cases such as this one that remind him of how far root canal therapy has come and the advantage recent technological advancements present for correct diagnosis and treatment planning.

“This case exemplifies the importance of proper diagnosis. The referring dentists immediately looked at #18 because of the prior treatment, but the patient’s chief complaint was extreme lingering pain to cold. The resorption of the filling material and root of tooth #18 would not cause the thermal sensitivity.”

Dr. Bruder stresses the importance that having a complete picture of the patient’s symptoms and complications plays in treatment planning. “Being able to see the size of the lesions on both #18 and #19 and seeing the location of the nerve and the resorption inside the root of #18 is vital.” That information, Dr. Bruder says, is fundamental for proper treatment planning and to choose treatment that will provide a successful outcome.

“I have had endodontists tell me that the outcomes haven’t changed since the day they started 20, 30 or even 40 years ago. But to those clinicians, I ask the question, ‘when the surgical operating microscope, ultrasonics and narrow field of view CBCT were introduced to endodontics, did you find yourself able to do more difficult cases than ever before?’ And their response is always yes. The outcomes have changed because we have more information than ever before and that information allows us to treat more teeth and establish a better treatment plan for the most difficult cases such as this one.”

1 Sedgley CM, Messer HH: Are endodontically treated teeth more brittle? J Endod 18:332-335, 1992.


George A. Bruder, D.M.D.
Dr. Bruder was the founding Chair of the Department of Endodontics and Director of the Advanced Specialty Education Program in Endodontics at Stony Brook University School of Dental Medicine from 2006 – 2015. In 2012, Dr. Bruder was awarded the prestigious Edward M. Osetek Educator Award from the American Association of Endodontists and is also a member of Omicron Kappa Upsilon, National Dental Honor Society. Dr. Bruder is a Diplomate of the American Board of Endodontics and the Coordinator of Micro-Endodontics and Endodontic Technologies in the Advanced Graduate Program in Endodontics at Harvard School of Dental Medicine. Dr. Bruder has delivered more than 500 lectures both nationally and internationally and published numerous articles on Micro-Endodontics and Endodontic technologies. In addition, he has authored and co-authored numerous text book chapters including the chapter on non-surgical Micro-Endodontic Retreatments with Dr. Robert R. White in Color Atlas of Endodontics, by Dr. William Johnson. Currently, Dr. Bruder divides his time between his family, private practice in Manhattan, NY, and providing the ultimate in hands-on participation continuing education programs held in Palm Beach Gardens, FL, at the facility he co-founded with Dr. Sergio Kuttler, International Dental Institute – Forever Learning (IDI-FL). Dr. Bruder serves as CFO and Director of Education.

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