Evaluation of Organic Debris Removal by 2 Irrigant Activation Systems using a Novel Chairside Quantitative Assay

This study aimed to investigate a novel quantitative adenosine triphosphate assay, to evaluate organic debris/bacterial reduction after irrigation activation with passive ultrasonic irrigation and the XP-endo Finisher (XPF), and to compare its efficacy with traditional colony-forming unit (CFU) detection in vitro.

The root canals of 40 extracted single-canal teeth were shaped to a 30.04 using NiTi files. Following inoculation of the root canals with Enterococcus faecalis for 3 weeks, the teeth were randomly allocated into 2 experimental groups (n = 20): (1) activation of 5.25% NaOCl using passive ultrasonic irrigation, or (2) activation using the XPF. The quantitative adenosine triphosphate assay (Endocator) was used before and after the irrigant activation protocols to determine the amount of bacteria/organic debris present. Data were analyzed using the Student t test and the Mann-Whitney U test (P = .05).

The Endocator raw score exhibited a strong correlation with the number of bacteria present, as determined by CFU counts (R² = 0.99). In contrast, Endoscore values showed a high correlation with the logarithmically transformed CFU counts (R² = 0.95). The amount of intracanal organic debris/bacteria remaining after the passive ultrasonic irrigation and XPF protocols was approximately 1.7% and 1.2%, respectively. No statistically significant differences were observed between the groups regarding the amount of residual bacteria remaining in the canals after the irrigation protocols (P > .05).

Both irrigation activation systems were similarly effective in removing organic debris/bacteria from the root canal system following final irrigation. None of the tooth samples was completely free of bacterial or organic debris residues after treatment with either of the tested systems.