Date of Award
Spring 1995
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Austin, B. P.
Abstract
In the early years of dentistry many threatening or misguided philosophies undermined the development of a scientific basis of endodontic therapy. Perhaps one of the earliest and most disruptive philosophies occurred in 1890 at McGill University, when William Hunter presented a paper by W.D. Miller, incorrectly indicating that restoring a persons dentition could result in systemic infection (1). By the late 1930's greater research and development enabled dentistry to advance and improve. Today, dentistry is foremost in the field of health care delivery. The specialty of endodontics has continued to evolve and has utilized new materials and equipment which are meant to continue the improvement of care provided by the profession. Experience and scientific evaluation of new devices and techniques such as nickel titanium instruments, surgical microscopes and apex locators, show that the premise on which endodontics is based has not changed. Even with all the new equipment available to make endodontic treatment easier, we must still access the tooth, understand the anatomy, locate, debride and shape the canals and completely obturate the root canal system in order to develop a hermetic seal (2,3). Our goals are therefore still the same in treating pulpal and periradicular disease, as success rates continue to improve (4,5,6). If after all possible nonsurgical root canal therapy has failed, endodontic surgery is a rational alternative. As with all treatments we must address the etiology. Two of the most common reasons for failure are, inadequate debridement of the root canal system or an inadequate obturation which compromises the seal (6,7). If the obturation is poor and irritants are present in the periapical region, then a root-end preparation with a retrofilling is required to debride the area and improve the seal. There have been many materials used as retrofills over the years, including: EBA (8,9,10,11,12), IRM (2,8,13,14), Diaket (7,15,16,17,18,19,20), Zinc-free amalgam (21,22), Mineral Trioxide Aggregate (23,24,25), cavit (26,27), composite resin (28,29), glass ionomer (30), Teflon (2) & Cyanoacrylate (31). Recently, Newlin (20) studied the sealing abilities of lRM, EBA and Diaket at 1 mm and 3 mm retrofilling depths in single rooted human teeth. He found that Diaket had significantly less leakage at 1 mm and 3 mm depths than both IRM and EBA. The results also showed that a 3 mm retrofill leaks less than a 1 mm retrofill. This study used an electrochemical analysis of microleakage on extracted, single rooted human teeth to evaluate the role of the dentinal tubules in the beveled surface and in leakage. With the beveled surfaces covered retrofills will be placed at 1 mm and 3 mm depths using IR.M, EBA and Diaket. The results will be analyzed to determine the effect on apical leakage by covering the beveled surface rendering it impermeable. The possible sources of leakage may be the bevel, material-dentin interface or gaps in the material itself.
Recommended Citation
Silver, Michael E., "The Effect on Microleakage of Exposed and Unexposed Dentinal Tubules on the Root end Resected Beveled Surface" (1995). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5382.
https://epublications.marquette.edu/theses/5382