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

• Published in: Brazilian dental journal 2014-09, Vol.25 (5), p.430-434
• Main Authors: Lorencetti, Karina Torales, Silva-Sousa, Yara Teresinha Corrêa, Nascimento, Gabriel Elias do, Messias, Danielle Cristine Furtado, Colucci, Vivian, Rached-Junior, Fuad Abi, Silva, Silvio Rocha Corrêa
• Format: Article
• Language: English
• ISSN: 0103-6440; 0103-6440
• DOI: 10.1590/0103-6440201302435

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 (p0.05) 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 (p0.05). 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. Este estudo buscou avaliar, por meio de microscopia eletrônica de varredura (MEV), a limpeza das paredes de canais com curvatura moderada, submetidos ao preparo biomecânico com diferentes diâmetros finais utilizando-se irrigação por pressão apical negativa. Trinta e duas raízes mésio-vestibulares de molares foram divididas em 4 grupos (n=8) de acordo com o diâmetro final dos instrumentos: GI: 30.02, GII: 35.02, GIII: 40.02 e GIV: 45.02. O procedimento de irrigação foi realizado a cada troca de instrumento com NAOCl 1% utilizando o sistema EndoVac. A irrigação final foi conduzida com EDTA 17% por 5 min. As microfotografias de MEV foram avaliadas sob aumentos de 35× e 1000×, por três examinadores calibrados, em estudo duplo-cego. Os dados foram submetidos ao teste de Kruskal-Wallis e pós-teste de Dunn (=0,05). Os canais instrumentados com diâmetros finais de 30.02 e 35.02 demonstraram mais debris, estatisticamente diferente dos demais grupos (p