Influence of Apical Enlargement in Cleaning of Curved Canals Using Negative Pressure System

Abstract

This study aimed to evaluate, by scanning electron microscopy (SEM), the cleaning of canal walls with moderate curvature subjected to biomechanical preparation with different final diameters using apical negative pressure irrigation. Thirty-two mesiobuccal roots of molars were divided into 4 groups (n=8) according to the instrument's final diameter: GI: 30.02, GII: 35.02, GIII: 40.02 and GIV: 45.02. Irrigating procedure was performed at each change of instrument with 1% NaOCl using the Endovac system. Final irrigation was conducted with 17% EDTA for 5 min. The SEM photomicrographs were evaluated under 35× and 1000× magnification, by three calibrated examiners, in a double-blind design. Data were submitted to Kruskal-Wallis and Dunn's post hoc tests (α=0.05). Canals instrumented with 30.02 and 35.02 final diameters showed more debris, statistically different from the other groups (p<0.05). Comparing each root canal third, for the cervical and apical portions no statistically significant difference (p>0.05) was found among the four groups. Regarding the presence of smear layer, canals with 30.02 final diameter showed the highest scores, statistically different from the 45.02 group (p<0.05) and similar to the 35.02 and the 40.02 groups (p>0.05). Although none of the studied diameters completely removed debris and smear layer, it may be concluded that instrumentation with higher final diameters was more effective in cleaning the root canals with moderate curvature.

Antimicrobial efficacy of different concentration of sodium hypochlorite on the biofilm of Enterococcus faecalis at different stages of development

“…The present study was carried out on straight roots. However, based on some previous studies the penetration of irrigation solutions into the apical areas of the root canal, especially in curved root canals, is limited (24-27). Therefore, it is recommended that similar studies be carried out in curved root canals, too, to make it possible to extend the results to real clinical conditions.…”

Effect of Passive Ultrasonic Irrigation on Enterococcus faecalis from Root Canals: An Ex Vivo Study

“…Biomechanical preparation using antimicrobial irrigants aims to eliminate infection from the root canal system (RCS) (4,5). However, the root canal system anatomy favors the maintenance of infection in the isthmuses, lateral and apical ramifications and flattened areas (6).…”

Cleaning of long oval canals with WaveOne Gold system associated with different irrigant agitation protocols

“…Once the literature reveals that limitations in endodontic treatment are also related to the variation of internal root anatomy 20 , the study of the apical region of mandibular incisors is opportune, because this dental group has root canals especially flatted and narrowed. Care during preparation of these teeth is necessary, because the greater enlargement of the apical third promotes more cleaning 6 , but it know that excessive instrumentation can lead the root weak 4 . Other justification to the method adopted here is due to the fact that protocols with an association of different instruments and irrigants are necessary to compare the performance in removing debris and smear layer 21 .…”

“…In the literature, findings indicate significant results regarding the reduction of root canal microorganisms using the combination of chemical and mechanical preparation 5 . Better results in terms of disinfection are found proportionally with the root canal enlargement, especially in the apical region 6 , when the benefits of the action of sodium hypochlorite solution (NaOCl) appear to be significantly increased 7 .…”