Date of Award
Spring 1996
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Austin, B. P.
Second Advisor
Kniaz, Avrom
Third Advisor
Gaffney, Joseph
Abstract
Accurate determination of canal length greatly enhances the prognosis of orthograde root canal therapy. The most n clinically accepted method of obtaining this length has been based on interpretation of radiographic images. There are a plethora of difficulties associated with obtaining a clinically diagnostic radiograph and with interpreting the image correctly. Distortion, anatomical barriers, physiologic barriers and patient concern about radiation exposure interfere with successful radiographic imaging. Even if an accurate representation of the tooth is produced on film, the standard practice of subtracting 0.5 millimeter to 1.0 millimeter from the measured file length inserted from reference point to apex does not ensure an accurate location of the minor constriction or major foramen. Kuttler, Green, and other authors have shown the eccentricity of the major foramen in relationship to the radiographic apex of the tooth. The major foramen was shown to coincide with the anatomical apex in less than 50% of cases studied by Kuttler and less than 92% of cases according to Burch and Hullen. These morphologic variances have the potential to generate large errors even under ideal conditions. Substantial advances in the determination of root canal length have occurred in the last fifty years. Electronic measurement of canal length has been an area of intense investigation and there have been many improvements. Early apex locators demonstrated accuracies ranging from 65% to 87% and required ideal canal conditions. The manufacturers of more recently developed apex locators appear to have overcome some of the difficulties and errors associated with earlier models. This study was undertaken to determine and compare the accuracy of current apex locators in vitro and in vivo with emphasis on each unit's performance in the clinical setting. Although electronic canal measuring devices have been available for over thirty years, clinicians continue to be reluctant to rely upon these instruments as the sole method of canal length determination. It is apparent that part of this reluctance is due to lack of experience or lack of formal instruction in a formal setting. It is also noted that many of the studies utilizing early models, while performing statistically well in vitro, failed to provide convincing results in vivo. Newer versions of electronic canal measuring devices operate on different principles and the manufacturers claim much improved performance compared to earlier models. Further research, both in vitro and in vivo, is needed to evaluate such claims. If such instruments are reliable, without or in conjunction with current radiographic techniques, the time required for root canal therapy would be decreased, the prognosis of treatment would improve, and patient exposure to radiation would decrease.
Recommended Citation
White, Patrick W., "An In Vitro and In Vivo Comparison of Electronic Root Canal Measuring Devices" (1996). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5469.
https://epublications.marquette.edu/theses/5469