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Endodontics - A Quarterly Newsletter on Dental Specialties
JADA Specialty Scan

Does calcium hydroxide reduce tooth strength?

It's commonly known that weakened dentin threatens fracture resistance. Although reports in the dental literature suggest that using calcium hydroxide (CH) for endodontic treatment may lead to weakening of the dentin, Turkish scientists at Istanbul University found limited long-term data on human teeth.

CH is used both in the short-term as an intracanal dressing for disinfection, and in the long term as a pulp-capping material. Despite the emergence of alternative materials, it remains preferred for a wide range of endodontic pathologies and indications, including optimal healing.

To gain a better understanding about safe usage, the researchers conducted an in vitro study to evaluate long-term effects of CH on microtensile fracture strength (MTFS) at successive time intervals. Their findings were published Feb. 26 in the online version of Dental Traumatology.

A total of 105 caries-free extracted mandibular incisors were collected from patients between the ages of 30 and 40. (Among all endodontically treated teeth, mandibular incisors most commonly contract vertical root fractures.) Root canals of all of the teeth were instrumented. The teeth were divided into seven groups of 15 each.

Group 1 was the designated control group. Teeth in Group 1 were sealed immediately and tested for MTFS.

Teeth in Groups 2 through 6 were vertically compacted with CH and a sterile saline solution mixture and sealed with temporary filling. The groups were tested for MTFS at the time intervals as follows:

  • Group 2:    30 days
  • Group 3:    90 days
  • Group 4:    180 days
  • Group 5:    270 days
  • Group 6:    360 days
  • Group 7:    540 days

Steady decreases in MTFS of teeth with CH-prepared root canals correlating to elapsed time occurred between the 180th and the 540th day, when compared with the control group. At the 540th day, fracture resistance was at its lowest.

The researchers concluded that within the limitations of their in vitro study, long-term CH treatments significantly reduce tooth strength, causing an increase in fracture risk

"To avoid the loss of endodontically treated teeth due to fracture, long-term intracanal CH medication should be avoided," the researchers said. "It seems important and necessary to search for alternative materials for this purpose."

The authors also called for further studies on human teeth to confirm their results, as well as alternative treatment procedures for root canal filling.

Consulting Editor: Dr. Susan Wolcott
Diplomate, American Association of Endodontists

Avoiding endodontic file breakage
image: Hand holding Endodontic file

There are few things more stressful for the clinician and more anxiety-provoking for the patient than endodontic file breakage. Its complications jeopardize overall treatment outcome, as well as the long-term prognosis of the tooth.

Due to their flexibility, rotary nickel-titanium (NiTi) files are now commonly used for endodontic procedures. Although they allow better canal access than hand stainless steel files, NiTi files are fragile and infrequently show wear to warn of impending breakage.

Causes, prevention and coping strategies for the problem are explained in a continuing education article published in the May 2013 issue of Compendium. The report, by Dr. James K. Bahcall of Midwestern University College of Dental Medicine, includes:

  • potential causes for separated endodontic rotary nickel-titanium files;
  • advice on how to prevent breakage;
  • descriptions on how to remove a broken file;
  • prognosis for instances when the separated file cannot be removed.
Among a series of author recommendations included in the summary are tips on how best to prevent breakage, including using hand files before rotary files, creating a straight line (glide path) of access into a canal, and preflaring the coronal portion before using a rotary file in the apical third.

New approaches to revascularization

A review article published in the March 2013 issue of the Journal of Endodontics explores revascularization treatment guidelines for infected, immature, permanent teeth.

At one time, it was believed that revascularization, which involves disinfecting the root canal, was not possible for such teeth. However, pioneers of regenerative endodontic procedures in the 1960s and 1970s demonstrated that infected dental pulp could survive. In the early 2000s, researchers believed that despite its challenges, the benefits of the procedure, when successful, made it worth the attempt.

The Israeli and Canadian authors investigating the topic conducted an in-depth search of the dental literature on revascularization and regenerative procedures. Their aim was to glean guidance about indications, preferred medications and treatment methods.

Their findings show that new approaches to clinical management of infected immature teeth "represent an improvement over older treatment protocols that have left the roots short and the walls of the root canal thin and prone to fracture." Even when the new approaches fail to achieve the desired result, they "leave the door open to other methods of treatment besides extraction," study authors noted.

Applying review and evaluation of the literature, the researchers outlined treatment plans. They noted that although no standard follow-up protocol exists for revascularization procedures, various clinicians have advised follow-up periods in case reports—some for as long as five years post-treatment.

In conclusion, researchers noted, "Like all dental procedures, careful case selection and full disclosure to the patient (and parent) regarding the goals and limitations of the treatment are essential to make this form of mainstream treatment as an acceptable alternative in the clinical management of infected immature teeth."

The authors expect that continued research on regenerative procedures will provide new answers and new directions, and that tissue engineering will be the dental treatment of choice in the not too distant future.

News You Can Use
CODA OKs revisions to advanced education programs

The Commission on Dental Accreditation in February approved revisions to Accreditation Standards on Advanced Education Programs in Endodontics. Instruction and clinical training in regenerative endodontics and revascularization will be new requirements for all endodontic programs in 2014.

Rapid growth in regenerative endodontics research and treatment was the impetus behind the American Association of Endodontics' proposal for revisions. The organization's leadership is enthusiastic about scientific advances that may lead to generating pulp-like tissue into teeth that have lost vitality through trauma or caries.

"As advancements in this area continue, it will be important for new endodontist practitioners to deliver biologically based regenerative endodontic treatments to help retain the natural dentition, the ultimate goal of any endodontic treatment," said Dr. Gary R. Hartwell, AAE president.

To learn more about regenerative endodontics, read the Spring 2013 issue of Endodontics:
Colleagues for Excellence.

To learn more about advanced education programs in your area, visit the AAE website

Joint symposium set for July 2014

Saving the natural dentition will be highlighted during the 2014 joint symposium entitled "Teeth for a Lifetime: Interdisciplinary Evidence for Clinical Success." The partnership program of the AAE, American Academy of Periodontology and the American College of Prosthodontists is set for July 19-20, 2014, at the Swissôtel, Chicago. Registration will open in early 2014. For more information visit

Office design is focus of next 'JADA Live' seminar

image: Dr. Tholen image: JADA logo

"JADA Live," a series of continuing education seminars that debut last year, will continue in 2013, starting with Dr. Mark Tholen's presentation "Advancing Your Practice Through Office Design" set for July 19 at The Westin San Francisco Market Street.

Dr. Tholen, a renowned author and lecturer on dental office design, will break down the office design process while teaching techniques for boosting office efficiency during a full-day session in the City by the Bay

JADA Live seminars are presented by the publishers of The Journal of the American Dental Association. Each seminar offers six hours of CE credit provided though the ADA's Continuing Education Recognition Program. For more information and to register for Dr. Tholen's presentation, visit

Other upcoming JADA Live topics and venues include:

  • "Dentistry in the Digital Age: Unlock Your Practice Potential"
        Aug. 9, 2013 — Nashville, Tenn.
        Sept. 27, 2013 — Houston, Texas
  • "Modern-day Treatment Planning — The Role of 3D Imaging"
        Sept. 13, Seattle, Wash.
JADA Live CE seminars are supported in part by DEXIS, Gendex and Henry Schien Dental.

Product Spotlight
ADA offers endo manual for GPs

image: Endodontics Manual

The ADA now offers the "Endodontics Manual for the General Dentist" (P045), written by two renowned endodontists, Drs. Martin Trope and Gilberto J. Debelian.

This easy-to-follow manual presents step-by-step instructions to help general practitioners to provide root canal therapy in cases that meet specific criteria — and to recognize when to refer to a specialist. Emerging technologies have expanded the role general dentists can play in treating patients with apical periodontitis, offering a high degree of predictability and success.

In language and illustrations that are clear, simple and direct, the manual presents readers a guide to diagnosing a problem, understanding the different treatment procedures available and what instruments to use in treatment.

Available to ADA members for $68 and nonmembers for $102, the softcover manual includes 84 pages with more than 150 illustrations. Also, the ADA Catalog is offering a special 10 percent savings on all ADA Catalog orders with promo code 13433E through June 30, 2013. To order your copy of the Endodontics Manual for General Dentists, go to or call 1-800-947-74746.

Essential Dental Seminars

Essential Dental Seminars, a state-of-the-art Hands-on Dental Education Center (HODEC) now offers the latest optics of the Seiler Microscopes..

The Seiler Scope provides better results, brighter images and the highest clarity for the dental professional. HODEC's award-winning two-day course is titled "Endodontic Techniques for Safe and Predictable Results" and is presented by Drs. Barry Musikant, Dr. Allan Deutsch and others.

For complete details, visit

What is Specialty Scan?
This is one in a series of quarterly newsletters updating dentists on selected specialties in dental care. This issue of JADA Specialty Scan is focused on oral and maxillofacial radiology. Other Specialty Scan issues explore endodontics and prosthodontics. The ADA has engages the specialty organizations in these areas, as well as its own Division of Science, to offer content we hope will be of interest to all dentists, generalists and specialists alike. We hope you find these newsletters enlightening and useful, and we welcome your feedback on this and every issue of Specialty Scan.
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Any statements of opinion or fact are those of the authors and do not necessarily reflect the views of the American Dental Association. Neither the ADA nor any of its subsidiaries have any financial interest in any products mentioned in this publication. Any reference to a product or service, whether in advertisements or otherwise, is not intended as an endorsement or as approval by the ADA or any of its affiliated organizations unless accompanied by an authorized statement that such approval or endorsement has been granted.

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