Master Class

PART III. Definitions, Classification, Etiology and Initiation Mechanism of Tooth Structure Cracks

Preview Only, Purchase Required For Full Program Access.

Effective Date: September 1, 2017
Expiration Date: August 31, 2020
Format: Self Instructional - Audio Visual Voice-Over with Slides
Estimated Completion Time: 2.0 hours

Getting Started

Read all the information presented below. When ready select the View Program or other appropriate tab above.

Program Summary

Clinical management of cracked teeth in dental practice is an area replete with misunderstanding and misinformation. First, the literature lacks prospective studies and clinically useful universal definitions. Second, although cracked teeth problems vary significantly in diagnosis, treatment and prognosis. The literature terminology does not specifically differentiate between “Fractured teeth”, “Cracked teeth”, “Cracked Tooth Syndrome”, “Green stick fractures” and “Incomplete coronal fractures”.

The author’s 3x3 Tooth Structure Cracks (TSC) classification, grouped the various terminologies which relate to the cracked or fractured teeth problems, under one term “Tooth Cracks”. Then defined and classified the “cracks” according to their anatomic, physical and pathologic characteristics.

Physically, “Tooth Cracks” are classified into:

  • Line Cracks
  • Fissure Cracks
  • Fracture Cracks

Anatomically, “Tooth Cracks” are classified into:

  • Marginal Ridges
  • Grooves
  • Surfaces

Pathologically, “Tooth Cracks “are classified into:

  • Contributory
  • Noncontributory
  • Partially Contributory

The webinar presentation shows how to differentiate between the harmless “noncontributory crack” and the harmful “contributory crack”.

Contributory cracks cause reversible and irreversible pulpitis, pulp calcification, pulp necrosis, periapical and periradicular lesions. On the other hand, noncontributory cracks could be microscopically visible microcracks or clinically visible line. These cracks remain at the early initiation or development stages for years. They remain still and stationery, cause no pulpal or periodontal pathology as long as they are not pressured, and stressed by new forces or loads. Forces such as root filling condensation or traumatic fitting of a post.

Updated information about the etiology and initiation mechanism of tooth cracks is presented focusing on:

  • Abusive restorative procedures that cause coronal cracks
  • Abusive mechanical endodontic procedures that cause radicular cracks
  • Abusive post placement procedures
  • Dental occlusion factors

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. Describe the AbouRass 3X3 TSC classification system.
  2. Classify tooth structure of crack (TSC) into -nonstructural limited to tooth enamel and structural that involves the tooth dentine.
  3. Differentiate between the three TSC types, line cracks, fissure cracks and -fracture cracks.
  4. Define the TSC components which cause or play part in the involved tooth problem as contributory.
  5. Define the TSC components which play no part in the involved tooth problem as noncontributory.
  6. Correlate endodontic lesion healing with noncontributory TSC.
  7. Correlate lack of endodontic lesion healing with contributory TSC.
  8. Discuss and review the incidence of microcracks in the crown’s dentine correlated with abusive restorative dentistry procedures.
  9. Discuss and review the incidence of line cracks in posterior teeth cavity preparations correlated with the incidence of Cuspal foundation cracks and complete Cuspal fractures.
  10. Discuss and review the incidence of microcracks in the root dentine correlated with abusive endodontic root canal preparation, obturation and post placement procedures.
  11. List and describe the preventative measures to reduce or prevent the effects of the restorative, endodontic and post placement TSC initiation and propagation factors.

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 2.0 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 2.0 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 2.0 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.

Viewing Information

System Hardware/Software and Internet Connection Requirements

The following information is provided for your reference in conjunction with review of this program.

General System and Internet Requirements:  Speakers or Headphones, High Speed Internet connection, Wireless 3G and 4G,
Web browsers: Internet Explorer 7.x or higher, Firefox 4.x or higher, Safari 2.x or higher and Chrome.

Operating Systems:  Windows 2000 or higher, (MS Surface and other MS mobile devices compatible), MAC OSX 10.3 or higher, Mac iOS 5.0 or higher (iPad, iPhone compatible), Android 4.3 or higher (most Android mobile devices compatible).