[A clinical evaluation of antimicrobial effectiveness of EDTA as an endosonic irrigant].

Recently the chelating agent EDTA has gained increasing attention by dentists, in view of the facts that it does not produce deleterious or corrosive effect when used as an irrigant for root canal debridement. However, the efficacy of EDTA as an irrigant in clinical practice is still not clear. Therefore, in this study EDTA was adopted as an irrigant alone to evaluate its antimicrobial effect as a reference for subsequent clinical application. One hundred single-root teeth were selected and evenly divided into 4 groups. The root canals were prepared with conventional hand filing or ultrasonic filing respectively and the canals were rinsed singly with either EDTA or distilled water for contrast. The contents of each root canal before and after debridement were cultured in an incubator. The results showed that EDTA with hand filing in 48 hours and with endosonics in both 48 hours and one week had better antimicrobial effect than did distilled water. The results also indicated that EDTA combined with endosonics manifested the best antimicrobial effect among the four groups in this experiment. The above-mentioned differences were statistically significant at the level of p less than 0.05 by Fisher's exact test.