Microbiological Evaluation of Different Irrigation Protocols on Root Canal Disinfection in Teeth with Apical Periodontitis: An In Vivo Study

Abstract

The present in vivo study was designed to evaluate the efficacy of apical negative pressure irrigation (ANP), passive ultrasonic irrigation (PUI) and positive pressure irrigation (PP) in the reduction of intracanal bacteria of dogs' teeth with pulp necrosis and apical periodontitis. Eighty root canals were randomly distributed into 3 experimental and 2 control groups according to the irrigation delivery system: group ANP (n=20), group PUI (n=20), group PP (n=20), group PC (positive control - sterile saline irrigation; n=10) and group NC (negative control - vital pulps not subjected to bacterial inoculation; n=10). The first sample (S1) was collected at baseline, and the second sample (S2) was collected after the disinfection protocols. All samples were seeded in culture media for anaerobic bacteria. CFU counts were analyzed statistically by the Kruskal-Wallis, Dwass-Steel-Critchlow-Fligner post-hoc and Chi-square followed by Tukey like multiple comparisons for proportions (α=0.05). All experimental groups were effective in reducing Gram-positive bacteria compared with PC (p<0.05). Regarding the reduction of Gram-negative bacteria, group ANP was significantly better than PP (p<0.05). No statistically significant difference could be found between PP and PUI (p>0.05). In dog's teeth with apical periodontitis, the use of ANP and PUI can be considered promising disinfection protocols as both delivery systems promoted a significant bacterial reduction.

Apical negative pressure irrigation versus syringe irrigation: a systematic review of cleaning and disinfection of the root canal system

“…Animal studies (Cohenca et al . , , Rodríguez‐Benítez et al . ) were excluded due to anatomical differences between human and animal teeth (Holland , Shen et al .…”

“…) or because the instrumentation protocol was not standardized (Cohenca et al . , ). Moreover, laboratory studies on artificial root canals (Townsend & Maki , Malentacca et al .…”

“…Animal studies (Cohenca et al 2013, Rodr ıguez-Ben ıtez et al 2015 were excluded due to anatomical differences between human and animal teeth (Holland 1992. Nevertheless, a sensitivity analysis revealed that these studies would not have been eligible even without this restriction either because they included immature teeth (Rodr ıguez-Ben ıtez et al 2015) or because the instrumentation protocol was not standardized (Cohenca et al 2013(Cohenca et al , 2015.…”

Instrument Design May Influence Bacterial Reduction During Root Canal Preparation

“…However, it is known that the endodontic treatment is performed in association with chemical substances, which are aimed to assist instrumentation and enhance disinfection (5,13,15,22). Previous studies (17,22) observed that chemical substances used as irrigant have antimicrobial activity and reduce the bacterial number in the root canal, while other authors (23) confirmed that sodium hypochlorite penetrates into dentinal tubules, and found that bacteria on root canal surface and dentinal tubules were significantly reduced when the antimicrobial agents were used (18). Moreover, bacterial remaining was found at S2 and S3 collection, the chemical substances could reduce the bacterial amount.…”

Tissue response to root canal irrigation systems in dogs’ teeth with apical periodontitis

“…014/2012). All the experimental procedures were performed in accordance with the protocol recommended by the International Organization for Standardization (ISO standard 7405:1997) [30] as our previous studies [31][32][33].…”