In Vitro Evaluation Of The Effectiveness Of XP-endo Finisher File On Smear Layer Removal After Root Canal Instrumentation

Objective:The purpose of this study was to evaluate the effectiveness of the XP-endo Finisher(XPF)and passive ultrasonic irrigation(PUI)in the smear layer removal of the root canal.It will provide a theoretical and experimental basis for root canal preparation in clinic.Methods:Sixty human single-rooted premolars were selected and decoronated to standardize the canal length to 16mm.Tooth were prepared by S3 rotary system to an root canal preparation of file size 3S,and then randomly divided into 6 groups according to the final irrigation protocol:XPF 3ml 30%NaOCl for 1 min(Group A),XPF 3ml 30%NaOCl for 1 min followed by 4ml 17%EDTA for lmin(Group B),PUI 3ml 3%NaOCl for 1 min(Group C),PUI 3ml 3%NaOCl for 1 min followed by 4ml 17%EDTA for lmin(Group D),3ml 3%NaOCl for 1 min using a syringe and a 30G side-vented needle(Group E),3ml 3%-%NaOCl for 1 min using a syringe and a 30G side-vented needle followed by 4ml 17%EDTA for lmin(Group F).After the completion of root canal preparation,the teeth were split into two halves longitudinally.The mean number of visible open dentinal tubules and the smear layers in the apical and middle thirds of the root canals were evaluated by SEM.Results:1.At the middle 1/3 and apical 1/3 areas,Group B and Group D had significantly more visible open dentinal tubules than the other four groups(P<0.05),with no statistical difference between Group B and Group D(P>0.05);2.Group E had less visible open dentinal tubules than Group A and Group C(P<0.05),with no statistical difference between Group A and Group C(P>0.05).Conclusion:There were no differences between XPF and PUI in the smear layers removal of the root canals.The XP-endo Finisher,as an new irrigation agitation technique,can help improve the smear layer removal.