Root Canal Completion Survival of Endodontically Treated Teeth

Journal of Endodontics, 42:11, 1598-1603, 2016 I. Pratt et al

The goal of most dentists is to have people, their patients, keep their natural dentition for their entire lifetime. In North America, organized dentistry has made incredible strides helping people keep their teeth, even through the era of high sugar, fast foods. The vast majority of Canadians have incredibly good access to high quality dental care. As a result, more people retain their teeth for a longer period of time, in better health, that ever before.

Not only do we strive to keep our patients healthy in the present but we are also tasked with determining, from both a health and cost-benefit standpoint, the effect of our treatment decisions five, ten, twenty years or more down the road. One of those treatment decisions we make, with our patients, is whether a tooth with pulpal damage should be retained with endodontic therapy or removed and replaced with an implant based crown. Numerous studies have shown that the long-term retention rate of implants and endodontically retained teeth are statistically comparable.

A number of factors can affect the successful retention of endodontically treated teeth (ETT). The quality of the root filling, coronal seal, type of coronal restoration, and periodontal health are all factors in ETT retention. As an endodontic specialist, it is not uncommon to see patients with failing ETT where the patient has failed to follow through on their dentist’s recommendations for placement of a permanent restoration following RCT. The result is the breakdown of the temporary restoration with coronal leakage and recontamination of the root canal system, or in the worst case, root fracture necessitating extraction of the tooth. It is incumbent upon us as dental professionals to appropriately communicate to our patients, further treatment which may be necessary for long term, ETT health. To this end we, the dental professionals, need to understand the research behind our treatment recommendations.

Pratt et al, in this retrospective study, looked at the type of post endodontic restoration and the time between RCT and crown placement, on tooth retention after eight years. 882 teeth, which met the inclusion criteria, had been endodontically treated by graduate students in endodontics. The teeth were either restored with full coverage crowns, amalgam or composite build-ups, or temporary restorations. All teeth were periodontally sound and showed no evidence of crown or root fracture when viewed under the surgical operating microscope. 441 teeth were restored with crowns, 198 with build-ups, and 243 only with temporary restorations.

Of the 882 teeth, 105 (11.9%) had been extracted after eight years. 777 (88.1%) survived. By category, 25 teeth were extracted from the crown group (5.7%), 23 extracted from the build-up group (11.6%), and 56 extracted from the temporary group (23%).

The authors also looked the time between endodontic treatment and crown placement. Crowns had been placed over a period of 8 months. The authors divided the ETT with crown placement teeth into two groups, those which had crowns placed within 4 months, and those which had crowns placed between 4 and 8 months. Of the 25 teeth which were extracted from the ETT with crown group, 6 had received crowns within 4 months, and 19 had received crowns between 4 and 8 months.

This study adds some data to what endodontic specialists have been recommending for year, namely that posterior, endodontically treated teeth, should receive full coverage restorations as soon as possible following RCT, but certainly no more than 4 months.

It has been my experience that some dental offices impose a mandatory wait period following endodontic treatment, ostensibly to allow for confirmation of healing. While this may make some sense from a financial perspective, it is not supported by the literature. It takes a year to adequately confirm radiographic healing in teeth with lesions of endodontic origin, far outside the 4 month recommendations of Pratt et al. With the use of the microscope and CBCT to ensure as much root canal anatomy as possible is cleaned, shaped, and filled in three dimensions, we can be confident of great healing results. There can be no reasonable rational for increasing the risk of catastrophic crown/root fracture by delaying placement of a final, full coverage, restoration.


About the Author, Dr. Howard Bittner, DMD, CAGS

Dr. Bittner was born and raised in the Surrey / Langley area. Following his pre-dental training at Simon Fraser University, he received his Doctor of Dental Medicine from the University of British Columbia in 1982 and his Certificate in Advanced Graduate Studies in Endodontics from Boston University’s Goldman School of Dental Medicine in 1995.
Dr. Bittner was in private practice in general dentistry for 11 years in Langley before his Endodontic specialty training. He has been practicing Endodontics since 1995.
In his free time, Dr. Bittner loves to participate in a variety of sports including most recent, golfing! He also enjoys being a grandfather to 3, which if you ask him is just the best!

On February 16, 2017, posted in: News for Doctors by