Master Class

PART II: How Tooth Structure Cracks Complicate and Affect Dental Treatments
Four (4) Teaching Cases

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Effective Date: September 1, 2017
Expiration Date: August 31, 2020
Format: Self Instructional - Audio Visual Voice-Over with Slides
Estimated Completion Time: 1.5 hours

Program Summary

In this part of the series we will demonstrate the important role of tooth structure cracks (TSC) in dental practice. It will show how undiagnosed or misdiagnosed tooth cracks can affect or complicate endodontic, periodontic or restorative treatments outcomes.

The program includes detailed histories of 4 substandard endodontically treated that were retreated and restored by general practitioners, and specialists. Either through case history progression or restoration removal, the 4 teeth were found having TSC.

Because of the retrospective nature of the analysis, it was impossible to determine whether the cracks were present prior to treatment and were missed, initiated or propagated during the treatment. What is important in this regard is to focus on the role of the cracks and their effect on the treatment outcome.

After a lengthy history of treatment, retreatment, recall and follow-ups, the 4 teeth were extracted and became teaching cases. each case is retrospectively analyzed its story and history is presented in the webinar.

The webinar presentation is organized to sharpen the dental professionals diagnostic skills, specifically increase their awareness to search for hidden line cracks concealed under crowns and large restorations. Especially Amalgam restorations in teeth planned for full crowns or full coverage restoration.

The lessons learned from these 4 teaching cases, have generated many guiding principles. Here are 3 examples:

  • Never do endodontic treatment or retreatment through defective or a mediocre crown.
  • The crown or the bridge dentists work hard to save is often the cause of the endodontic or periodontic problem.
  • Endodontic surgery is not a substitute for standard endodontic treatment or retreatment.

Target Audience

The target audience for this course is Dentists and Dental Specialists from novice to advanced. No prerequisites required.


Marwan Abou-Rass DDS. MDS. Ph.D

Marwan Abou-Rass DDS, MDS, Ph.D

Professor Emeritus,
Herman Ostrow School of Dentistry
University of Southern California

Dr. Abou-Rass brings nearly fifty years of cutting edge innovations in the field of endodontics and dental education. He pioneered the concept teaching molar versus central teeth as the best sequence for learning endodontic skills and developed the critical error approach to clinical performance evaluation.

In clinical endodontics, Dr. Abou-Rass has made a number of significant new concept and methodology contributions including:

  • Stressed pulp concept
  • Anti-curvature filing method
  • 4R Operational Diagnosis Protocol
  • Composite Post and Core buildup protocol
  • Endodontic Treatment Finalization Protocol
  • Interim Endodontic Therapy for native bone regeneration before implant placement

In addition to his DDS, Dr. Abou-Rass holds a Master’s degree in Dental Science in Prosthodontics , a certificate in Endodontics and a Ph.D., in Higher Education from the University of Pittsburgh, Pennsylvania. Dr. Abou-Rass served as Endodontic Department Chairman and Director of the Advanced Endodontic program at the University of Southern California, School of Dentistry (1971-2000). Dr. Abou-Rass moved to Riyadh, Saudi Arabia in 2000, where he directed the AEGD program at PAADI from 2000 to 2012.

Currently he is USC Professor Emeritus and publisher of Dental Economics MENA Journal and

Educational Objectives

At the end of this educational activity the dental professional should be able to:

  1. List the following complications as possible consequences of performing endodontic, restorative treatment on a tooth with an undiagnosed, or hidden tooth structure line crack.
    • Propagation of the line crack into fissures and fractures cracks.
    • Development of Pulpal disease.
    • Development of Apical Periodontitis
    • Development of Periradicular lesions
    • Development of Isolated periodontal pockets
    • Restorative failures
  2. Explain why the dental professional should avoid performing endodontic treatment or retreatment through existing old or defective restorations.
  3. Identify the following pitfalls and/or complications, which may occur if endodontic treatment or retreatment is performed through an existing full coverage restorations:
    • Porcelain or Zirconia Crown fracture
    • Burr perforations of the tooth
    • Difficulty or Inability to locate root canal orifices because of the crown restoration realignment or the position of crown margins.
    • Inability to detect pulp chamber floor gouges and perforations.
    • Inability to detect tooth structure cracks in the axial walls or the floor of the pulp chamber
    • Inability to detect recurrent caries
    • Endodontic instrument breakage
    • Damaging crown cementation causing future leakage and crown loosening.
  4. Discuss the clinical benefits of adopting the philosophy of comprehensive quadrant diagnosis.
  5. Describe why avoiding single tooth examination and diagnoses in situations where the more than one tooth is involved in dental quadrant is important.
  6. Review the guiding principle that apical surgery is not a substitute for standard endodontic treatment or retreatment.
  7. Discuss the concept that TSC propagation from one stage to another occurs because of additional forces.
  8. Recognize that early detection of noncontributory, tooth structure line cracks early would prevent their propagation into contributory tooth structure fissure and fracture cracks.
  9. Describe the benefits of using the periodontal probing test to differentiate between isolated periodontal pockets (IPP) and aggressive periodontitis pockets.
  10. Review the guiding principle that IPP healing differentiates between contributory and not contributory tooth structure line cracks, fissures and fractures.

Recognition and Credits

ADA CERP and PennWell Logos

PennWell Corporation is an ADA CERP recognized provider.

ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry.

Continuing education credits awarded for participating in the CE activity may or may not apply toward license renewal or specific license requirements in all states. It is the responsibility of each participant to verify the requirements of his/her state licensing board(s).

PennWell designates this activity for 1.5 credit hours of continuing education credits.

Concerns or complaints about a CE provider may be directed to the provider or to ADA CERP at

AGD PACE LogoThe PennWell Corporation is designated as an Approved PACE Program Provider by the Academy of General Dentistry. The formal continuing dental education programs of this program provider are accepted by the AGD for Fellowship, Mastership and membership maintenance credit. Approval does not imply acceptance by a state or provincial board of dentistry or AGD endorsement. The current term of approval extends from (11/1/2015) to (12/31/2019) Provider ID# 320452.

Dental Board of California: Provider 4527, course registration number 01-4527-15160.
“This course meets the Dental Board of California’s requirements for 1.5 unit of continuing education.”

Requirements For Successful Completion

To receive credit for your participation in this webinar you will be required to complete the online program examination. To complete the online examination participants must be registered and signed-in to this website and have reviewed the program in its entirety. At the end of the program a link will be provided directing you to the program course exam. Once completed and submitted an immediate grade report will be displayed. All participants scoring at least 70% on the examination will receive a CE Verification Form verifying 1.5 CE credits. Verification forms may be viewed and printed immediately as well as accessed anytime in the future (24/7) from within the user records page of this website.

Not enough time to complete your online examination? No problem, online examinations may be completed anytime during the effective period of the program. Participants requiring more time to complete an examination may return to this website, sign-in and complete the online examination.

Disclosure Declaration

Presenter Disclosure: Dr. Abou-Rass, has no financial interest in any of the products or manufacturers mentioned

Commercial Support: This course was developed without commercial support.

Provider Disclosure: PennWell does not have a leadership position or a commercial interest in any products or services discussed or shared in this educational activity, No manufacturer or third party has had any input into the development of course content.

CE Planner Disclosure: Heather Hodges, CE Coordinator does not have a leadership or commercial interest with any commercial supporter, or with products or services discussed in this educational activity. Heather can be reached at

Image Authenticity: No images in this educational activity have been modified or altered.

Scientific Basis: All content has been derived from references listed and/or the author’s clinical experience.

Known Benefits and Limitations: Information presented in this educational activity represents best practices in evidenced based dentistry with potential benefit for the patient and clinician. No off label or experimental treatments are discussed.

Educational Disclaimer: Completing a single continuing education course does not provide enough information to result in the participant being an expert in the field related to the course topic. It is a combination of many educational courses and clinical experience that allows the participant to develop skills and expertise.

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