Poster Presentation

Poster Presentation

PR25 - Change in Working Length at Different Stages of Instrumentation as a Function of Canal Curvature

Thursday, April 26
10:00 AM - 1:00 PM
Room: Exhibit Hall

Introduction: The aim of this study was to determine the change in working length (∆WL) before and after coronal flaring and after complete rotary instrumentation as a function of canal curvature. Methods: One mesiobuccal or mesiolingual canal from each of 43 extracted molars had coronal standardization and access performed. The first WL measurement was taken, followed by coronal flaring with Gates Glidden drills and complete rotary instrumentation with EndoSequence files. WLs were obtained at three time points: pre-instrumentation (unflared), mid-instrumentation (flared) and post-instrumentation (concluded). Measurements were made via direct visualization (DV) and the CanalPro apex locator (EM) in triplicate by a single operator with blinding within the time points. Root curvature was measured using Schneider’s technique. ∆WL was assessed using repeated-measures ANOVA. Results: The average curvature was 27.7° (range=9.8° to 50.1°). ∆WL across the time points varied by root curvature (p=0.001). For direct measurements in straight teeth (15°), ∆WL unflared to flared was 0.064 mm and flared to concluded was 0.372 mm; in curved teeth (40°), ∆WL unflared to flared was 0.062 mm and flared to concluded was 0.251 mm. For electronic measurements in straight teeth, ∆WL unflared to flared was 0.087 mm and flared to concluded was 0.218 mm; in curved teeth, ∆WL unflared to flared was 0.085 mm and flared to concluded was 0.100 mm. Conclusions: A greater change was seen in WLs determined from the flared to the concluded canal than from the unflared to the flared canal. This change was greater in straight canals versus curved canals.

Mei I. Tang

Endodontic Resident
Virginia Commonwealth University

Originally from Macau, China, Mei Tang came to the US to pursue higher education. She graduated from University of Pittsburgh School of Dental Medicine and completed a general practice residency at Allegheny General Hospital in Pittsburgh. She then moved to Richmond, Virginia for a one-year endodontic internship. She is now a second year endodontic resident. In her spare time, she enjoys baking, tennis and Argentine tango.


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Garry L. Myers

Graduate Program Director
Virginia Commonwealth University

Dr. Garry Myers currently serves as the graduate endodontic program director at Virginia
Commonwealth University in Richmond, Virginia. He completed his dental school
education at the University of Texas Health Science Center/ at San Antonio in 1985.
Following graduation Dr. Myers entered the USAF where he served for four years as a
general dentist before entering the endodontic residency program at Wilford Hall Medical
Center at Lackland AFB also in San Antonio. In 1998 after serving on active duty for 13
years, Dr. Myers left the USAF to enter private practice in Olympia, Washington where he
practiced for the next 16 years. In the summer of 2014, full time education entered the
picture when Dr. Myers accepted a position at VCU where he now works. He is currently
the president of the American Association of Endodontists having been involved over the
last nine years with various committees of the AAE as well as serving on the Board of


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Richard Archer

Associate Dean of Clinical Education
Virginia Commonwealth University

Dr. Archer earned his D.D.S. degree from The University of Maryland Dental School in 1982. He was sponsored by the United States Navy for specialty training and graduated from The Ohio State University College of Dentistry in 1990 with a Certificate in Endodontics and a M.S. degree. After 11 years as a Navy Dental Officer, Dr. Archer was active in private practice for 17 years in Chesapeake, Virginia.
While teaching in the Navy GPR program at Naval Hospital Portsmouth, VA, Dr. Archer began teaching part time at the VCU School of Dentistry. He continued as an adjunct faculty member for 18 years before becoming full time faculty in 2009. Dr. Archer achieved his board certification in 2011 and is a Diplomate of The American Board of Endodontics.
Dr. Archer was the Predoctoral Endodontics Director from 2010 until 2016 and the Interim Chair of the Department of Endodontics from 2012 until 2014. He is still involved in teaching endodontics both on the predoctoral and graduate levels. Since 2013 he has been the VCU School of Dentistry Associate Dean for Clinical Education.


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Alvin Best

Virginia Commonwealth University

3/11–Present: Director of Faculty Research Development and Professor (Associate Professor
until 2013), Department of Periodontics, Virginia Commonwealth University
PhD, (1984) Biostatistics, Medical College of Virginia at Virginia Commonwealth University,
Richmond, VA USA
MA, (1978) Quantitative Psychology, L.L. Thurstone Psychometric Laboratory, University of
North Carolina, Chapel Hill, NC USA
BS, (1973) Mathematics and Psychology, University of Tennessee, Knoxville, TN USA.
Recipient of the Torchbearer award.


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PR25 - Change in Working Length at Different Stages of Instrumentation as a Function of Canal Curvature

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