Date of Award

Spring 1998

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)




The goal of root canal therapy is elimination of bacterial and pulpal tissue from the root canal system. This is followed by a complete three dimensional obturation of the canal system. Every one of these steps play an important role in the success of root canal therapy. This goal of complete debridement is never fully achieved due to presence of lateral canals, isthmuses and other anomalies. It has been demonstrated by various studies that regardless of the technique used to prepare the canal, debris and tissue still remain within the canal system (1-2). Rosen and Marshal (3) found organic tissue in the irregularities of the main canal after conventional instrumentation. Gutierrez and Garcia(4) illustrated the presence of fins in the canal that were never touched by hand instrumentation. Modem materials and techniques have improved the predictability of debridement of the main root canal system. This has been accomplished by combining thorough mechanical preparation with chemical dissolution of tissue. However, there is still a problem in cleansing small accessory canals due to inaccessibility of these canals. Lack of debridement and obturation of these fine lateral canals can result in failure. It has been reported that chemomechanical preparation using a combination of 5.25 percent sodium hypochlorite with 3 percent hydrogen peroxide or normal saline was not effective in total debridement of tissue debris in the canal system (5). Senia was able to show that hand instrumentation and 5.25 per cent sodium hypochlorite does not effectively remove debris from the apical one third of the canal (6). Richman (7) was the first to describe use of ultrasonic instrument for in root canal preparation. Since then, there have been a series of studies regarding the use of this instrument (8-12). Weller et al (13) found no significant differences when he compared conventional hand instrumentation with ultrasonic instrumentation in debriding the canal. In addition, he concluded that ultrasound could be used as a significant aid in increasing the efficiency of endodontic debridement rather than an alternative to conventional hand instrumentation...



Restricted Access Item

Having trouble?