Root canal success related with the step start from preparation until obturation to create a good sealing ability between root canal wall and root canal filling materials. The purpose of this study is to determine the difference of sealing ability in the root canal between glass ionomer and epoxy resin, irrigated and non-irrigated with NaOCl 5,25%. The research design was clinical experimental using mandibula premolars which have been extracted. All of the sampels was prepared, then irigated and obturated with the differences on the treatment of each group. Group A (SIK + NaOCl 5,25%), B (SIK + aquabides), C (AH Plus + NaOCl 5,25%) and D (AH Plus + aqubides ). The next step is covering the teeth with nail polish , then all group were incubated in 37°C during 24 hours, after that soaked on black tint during 7 days and the last step was cutting the teeth with separating disk. The samples were observed for black ink penetration using stereo microscope. The result was analyzed by Kruskall wallis test and Post hoc Mann- whitney Utest. The result from this study shows there is difference of sealing ability in root canal wall using glass ionomer type 1 and epoxy resin (AH Plus) that irrigated or non-irrigated with NaOCl 5,25%. (p<0,05). Group with AH Plus sealer which irrigated with aquabides has the best sealing ability.