Abstract
This study aimed to evaluate, by means of scanning electron microscopy (SEM), the cleaning of flattened root canals, varying irrigation/aspiration protocols during biomechanical preparation. Thirdy human mandibular incisors were distributed into three groups (n = 10) according to the aspiration/irrigation protocols: conventional, conventional + brush, and apical negative pressure irrigation. Irrigation procedure was performed with 5 mL of 1% NaOCl at each change of instrument; final irrigation was conducted with 17% EDTA for 5 min. After biomechanical preparation, the roots were sectioned and prepared for SEM analysis. The images obtained were evaluated under 35× and 1,000× magnification by three calibrated examiners, following a double-blind design. All data were analyzed using Kruskal-Wallis and Dunn's post hoc tests (α = 0.05). Canals wherein the conventional method and apical negative pressure irrigation were employed revealed less debris, statistically different from the conventional + brush group (p < 0.05). Regarding the presence of smears, apical negative pressure irrigation was more effective in cleaning, showing lowest scores (p < 0.05), compared with the other tested protocols. Comparing each root canal third revealed that the apical portion was difficult to clean as all the tested protocols showed similar high scores (p > 0.05), both for the presence of debris and smear layer. In conclusion, although none of the studied irrigation/aspiration protocols have completely cleaned flattened root canals, apical negative pressure irrigation was more effective in smear layer removal, whereas the conventional + brush protocol was the least effective in removing the debris and smear layer.
Highlights
The removal of vital and necrotic pulpal tissues, microorganisms, and bacterial products from the root canal system is important in endodontic therapy.[1]
The present study aimed to evaluate, by scanning electron microscopy (SEM) analysis, the removal of debris and smear layer from flattened root canals by comparing three irrigation/aspiration protocols: conventional, conventional + brush, and apical negative pressure irrigation
Significant differences in debris removal in the entire root canal were observed among the groups (p < 0.05), with conventional irrigation and apical negative pressure irrigation showing lesser debris, being statistically similar between them (p > 0.05) and different from conventional + brush group (p < 0.05), in which more debris was found
Summary
The removal of vital and necrotic pulpal tissues, microorganisms, and bacterial products from the root canal system is important in endodontic therapy.[1] around 35% of canal walls remain untouched by instruments during biomechanical preparation;[2] an efficient irrigation is necessary for a successful endodontic treatment. Because of the anatomical complexity of root canals, an effective contact of the irrigating solutions with the entire canal walls is. Irrigation/aspiration techniques have been proposed for enhancing the effectiveness of irrigation solutions on the root canal system.[5]. The physicochemical properties inherent to each irrigating solution and its continuous renewal during biomechanical preparation maintain debris in suspension within the canal, preventing saturation and precipitation of particles[6] and favoring their removal with the irrigation/aspiration process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
