The Effect Of Root Canal Irrigation On Apical Microleakage With Single Point Method

Aim:To investigate the effect of different root canal irrigation methods on the microleakage of the apical region after single point filling with iroot SP in vitro.Methods and Materials: 90 premolars with closed apical foramen,which ware extracted due to orthodontic treatment,were selected.After the remove of the crown and the initial expansion of fixed length using stainless steel RT file,the root was gradually expanded to 40 with waveone system.90 samples were randomly divided into 6 groups(15 in each group).Group A: conventional injection needle washing;group B: ultrasonic swabbing;group C: laser swabbing D gear;group D: laser swabbing D + gear;Group E: ultrasonic + laser D gear;Group F: ultrasonic + laser D +gear.Each root canal was rinsed with 3% sodium hypochlorite for 60 seconds in each group,then rinsed with normal saline for 15 seconds,then was dried and filled with irootsp single point method.15 teeth in each group were randomly divided into 3subgroups,5 teeth in each group.Each subgroup corresponds to dye penetration time of7 days,30 days and 90 days respectively.After the tooth surface was naturally dry,nail polish was used to close the tooth tissues outside the root tip area 2mm.Dye penetration test was carried out in vitro with 2% methylene blue and combined with the transparent tooth technique to observe the microleakage in the apical regions of the subgroups in 7 days,30 days and 90 days.The data were read and recorded by 40 X calibration microscope,and the data were analyzed by SPSS25.0 software package,andα=0.05.Results:7 days after filling,group B,C and E showed better root canal sealing,which was statistically significant compared with group A(P = 0.001,0.001,0.002);30 days after filling,group B and group C showed better root canal sealing,which was statistically different from group A(P = 0.002,0.003);90 days after filling,only group C showed better root canal sealing,which was statistically significant compared with group A(P = 0.002).According to the time sequence,there was no significant difference between groups a,B and D in the apical microleakage(P =0.107,0.051,0.774)and in the apical microleakage(P = 0.013,0.001,0.001).C.There was significant difference between group E and group F at 7 and 30 days(P =0.028,0.001,0.001),but there was no significant difference between group E and group F at 30 and 90 days(P = 0.675,0.268,0.749).Conclusion:In the case of 3% sodium hypochlorite,compared with the application of needle washing,ultrasonic swabbing,high power Nd: YAP laser and ultrasonic swabbing combined with Nd: YAP laser,low power Nd: YAP laser alone was used for root canal swabbing for 60 s.In 90 days after root SP single tip method was used for root canal filling,the best sealing of root tip area was achieved.