Penetration of Heated and Non-Heated Sodium Hypochlorite into Lateral Canals by Apical Negative Pressure Irrigation

The role of irrigation in root canal treatment is crucial; sodium hypochlorite is the most commonly used irrigant. Many methods were used to potentiate sodium hypochlorite, one of which is heating of the irrigant. Negative pressure irrigation is a new method of irrigation that was introduced to deliver the solution through the whole root canal length. Sixty single rooted teeth were used in this study. A total of 360 simulated lateral canals were created, 6 in each tooth, with 2 lateral canals at 2, 4.5 and 6 mm of working length. To resemble the clinical situation, a closed system was created by coating each root with soft modeling wax. Roots were then randomly assigned to 3 experimental groups: group 1 (n = 20): apical negative pressure irrigation (ANP); group 2 (n = 20): apical negative pressure irrigation with heated irrigant (ANP + Heat); and control group 3 (n = 18): positive pressure irrigation. The samples were evaluated by direct observation of the images recorded by a photography machine. The results showed that ANP and ANP + Heat were more effective than needle irrigation at lateral canal penetration, but there was no significant difference between the groups 1 and 2. Apical negative pressure irrigation is more effective than needle irrigation in penetrating into lateral canals. Heated irrigant did not penetrate better into these canals. Resume Le role de l’irrigation dans le traitement du canal radiculaire est crucial; l’hypochlorite de sodium est la solution d’irrigation la plus utilisee. De nombreux procedes ont ete utilises pour potentialiser l’action de l’hypochlorite de sodium, dont l’echauffement de l’irrigant. L’irrigation negative sous pression est une nouvelle methode d’irrigation qui a ete introduite pour delivrer la solution sur toute la longueur du canal radiculaire. Soixante dents monoradiculees ont ete utilisees dans cette etude. Un total de 360 canaux lateraux ont ete crees, 6 dans chaque dent, avec 2 canaux lateraux a 2, 4,5 et 6 mm de longueur de travail. Pour simuler les memes conditions cliniques, un systeme ferme a ete cree par le revetement de chaque racine avec de la cire a modeler. Les racines ont ensuite ete reparties au hasard a 3 groupes experimentaux: groupe 1 (n = 20): irrigation apicale sous pression negative (ANP); groupe 2 (n = 20): irrigation apicale sous pression negative avec irrigant chauffe (ANP + chaleur); et le groupe temoin 3 (n = 18): irrigation sous pression positive. Les echantillons ont ete evalues par observation directe des photos enregistrees par un appareil de photographie. Les resultats ont montre que l’ANP et l’ANP + chaleur etaient plus efficaces que l’aiguille d’irrigation a la penetration du canal lateral, mais il n’y avait pas de difference significative entre les groupes 1 et 2. L’irrigation apicale sous pression negative e s t plus efficace que l’irrigation sous pression positive. L’irrigant chauffe ne penetrait pas mieux dans les canaux.