Chulalongkorn University Dental Journal

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Objective To assess the volume of sodium hypochlorite (NaOCl) that was apically extruded from teeth prepared to different apical sizes during irrigation using an EndoActivator compared with using a needle and a syringe. Materials and methods One hundred single root canals were instrumented and randomly divided into three experimental groups (n = 30) with final apical sizes of #35, #50, or #80. Each tooth was fixed in an agarose gel model and irrigated with 2.5% NaOCl using a needle and a syringe irrigating technique. The tooth was removed, cleaned, dried and re-fixed in a new agarose gel model prior to irrigating with an EndoActivator. Apical extrusion was assessed by the weight difference before and after each irrigation and confirmed by the color change of a pH-indicator in the gel model. Data were analysed by Kruskal-Wallis test and the Mann-Whiney rank sum test for pairwise comparisons. Results There was no color or weight change in the size #35 group. Apical extrusion of NaOCl occurred in teeth prepared to apical size #50 or #80. The extrusion volume was increasing when the apical size was larger and was significantly higher in the needle-syringe groups than in the EndoActivator groups (p < 0.05). Conclusion Extrusion occurred in teeth prepared to apical size #50 or #80. Extrusion was significantly reduced when using the EndoActivator compared with the needle and a syringe technique.



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