Comparison in amount of sodium
hypochlorite extrusion during irrigation
with needle-syringe and EndoActivator:
in vitro study 
- Nattaya Rungcharoenporn D.D.S.
- Somsinee Pimkhaokham D.D.S., Ph.D.
Abstract :
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.
(CU Dent J. 2014;37:39-46)
Keywords :
apical preparation size; EndoActivator; extrusion; irrigation; sodium hypochlorite