Date of Graduation

2007

Document Type

Thesis

Degree Type

MS

College

School of Dentistry

Committee Chair

C. Russell Jackson

Committee Member

Michael D. Bagby

Committee Member

Thomas F. Razmus

Abstract

The purpose of this study was to compare the leakage of an MTA apical barrier after final irrigation with 3% sodium hypochlorite, 2% chlorhexidine, 17% EDTA/3% sodium hypochlorite, or MTAD. Seventy single-rooted extracted teeth were accessed and the apical three millimeters of the root resected. The teeth were then instrumented with Profile Series 29 0.04 taper #7 to the apex. The same rotary instrument was then placed in the apical opening and advanced until D16 was even with the resected root-end. The teeth were randomly assigned to the four test groups (five were used as positive controls and five as negative controls). After being placed in flower arrangement foam, the final test irrigant was introduced for five minutes. The canals were dried and a five millimeter MTA plug was introduced to the apex. After allowing twenty-four hours for an initial set, the teeth were exposed to methylene blue dye. They were then demineralized, dehydrated, and cleared to allow visualization of the leakage. The amount of leakage was evaluated with a measuring microscope in millimeters. Data were analyzed using a one way ANOVA and Tukey’s HSD test. Results indicated significantly less leakage occurred in the 3% sodium hypochlorite group compared to the 17% EDTA/3% sodium hypochlorite and MTAD groups (p< 0.05). While 2% chlorhexidine exhibited less leakage than 17% EDTA/3% sodium hypochlorite and MTAD, the difference was not significant; in addition, the amount of leakage seen in the 2% chlorhexidine group was not significantly more that that seen with 3% sodium hypochlorite (p>0.05). In this in vitro model, a final rinse with 3% sodium hypochlorite appears to be most beneficial prior to placement of an MTA plug; removing the smear layer seems to decrease the ability of MTA to provide an apical seal

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