ABSTRACT
The purpose of this invitro study was to evaluate the antimicrobial effectiveness of three common gutta percha solvents [Chloroform, Eucalyptol and Halothane] on Enterococcus faecalis biofilm when used during endodontic retreatment. Extracted human mandibular premolars were instrumented, infected with E. faecalis, and obturated. The gutta-percha was removed mechanically in the presence of saline or chemo-mechanically in the presence of either chloroform, Eucalyptol or Halothane. Bacterial samples were collected after gutta-percha removal, and colony-forming units [CFU] per ml were enumerated. Results showed that there was a statistically significant reduction in the mean numbers of colony forming units [p<0.05] after the Chemo-mechanical removal of gutta percha using rotary nickel titanium retreatment instruments with Chloroform, Eucalyptol or Halothane. However, the difference in the antimicrobial effectiveness among the three tested gutta percha solvents was statistically non-significant [p<0.05]
ABSTRACT
Antimicrobial agents used during root canal treatment should ideally reach inaccessible sites and would selectively destroy endodontic pathogens. Different auxiliary chemical agents for root canal preparation have been proposed and the most commonly used in endodontics is sodium hypochlorite. This study aimed at evaluating of altering the pH value of sodium hypochlorite on its antibacterial effectiveness against Enterococcus faecalis [E. faecalis] biofilm. Three different sodium hypochlorite solutions with different pH values [alkaline, neutral and acidic] were prepared. One-hundred seventeen canine halves [root canal dentin] and 117 cellulose nitrate membrane filters were used. They were classified according to the test solutions into three equal groups [n=39] according to the immersion in alkaline, neutral or acidic solutions and were further subdivided into another three equal groups [n=13] according to the immersion time [5 min, 30 min and 60 min]. E. faecalis biofilm was developed onto both root canal dentin and cellulose nitrate membrane filters. The antimicrobial effect of test solutions was assessed quantitatively by bacterial count and qualitatively by Scanning Electron Microscope [SEM] examination. The antimicrobial effect of test solutions against E. faecalis biofilm developed onto root canal dentin [using bacterial count] showed that the difference in the mean bacterial count between all groups after all immersion times was statistically significant, except for the difference of acidic versus alkaline solution after 60 min immersion period. While the antimicrobial effect of test solutions against E. faecalis biofilm developed onto cellulose nitrate membrane filters provided that the mean bacterial count recorded after 5 min immersion period for the acidic sodium hypochlorite was significantly different in comparison with either the neutral or the alkaline solutions. After 30 min immersion period, the neutral sodium hypochlorite solution was significantly different in comparison with either the acidic or the alkaline solutions. Total elimination of the bacterial biofilm achieved only after the immersion for 60 min. Using [SEM] the acidic solution for both dentin and cellulose nitrate membrane filter samples showed total elimination of the bacterial biofilm only after the 60 min immersion, but neutral solution was not capable of total elimination of the bacterial biofilm at all time intervals. Finally, the alkaline solution was the only solution capable of removing the bacterial biofilm at all immersion periods. When root canals were irrigated with alkaline sodium hypochlorite the resultant radicular dentin walls were free of debris and the dentinal tubule entrances were visible