Abstract: Objective:?To investigate the clearance of SDSn solution on Vitapexpaste. Methods:?The area of Vitapex paste in the root canal before and after irrigation was calculated by X-ray films, and the clearance rate of Vitapex paste in the root canal under different irrigation schemes was compared. Straight root canal modules were selected,and the optimal concentration of SDSn for removing Vitapex paste in the root canal was screened out. The clearance efficiency of Vitapex paste in straight root canals by distilled water, 1% NaClO, 17% EDTA, 7% maleic acid (MA), 10% citric acid (CA), and 1% SDSn was compared. The clearance efficiency of Vitapex paste in straight root canals by different instruments combined with solutions such as 1% NaClO + H-file (HF), 1% NaClO+ Gentlefile Brush (GF), 1% SDSn + HF, and 1% SDSn + GF was compared. 25° curved root canal modules were selected, and the clearance efficiency of Vitapex paste in curved root canals by different irrigation needles combined with solutions such as 1% NaClO+ double-ended irrigation needle, 1% NaClO + IrriFlex irrigation needle, 1% SDSn + double-lumen flushing needle, and 1% SDSn + IrriFlex irrigation needle was compared. Results:?The clearance rate of Vitapexin 1% SDSn groupwas higher than that of 0.1% SDSn group (P＜0.05), but there was no significant difference compared with 5% SDSn groupand 10% SDSn group (P＞0.05). The clearance rate of Vitapex by 1% SDSn group was higher than that of 1% NaClO group, 17% EDTA group, 7% MA group, and 10% CA group (P＜0.05). In straight root canals, the use of Gentlefile Brush significantly increased the clearance rate in 1% NaClO + GF group (P＜0.05), but did not significantly increase the clearance rate in 1% SDSn + GFgroup (P＞0.05). In the middle and lower segments of curved root canals, 1% SDSn + IrriFlex needle group significantly increased the clearance rate compared with 1% SDSn + double-lumen flushing needle group (P＜0.05). Conclusions: 1% SDSn is efficient in removing Vitapex paste from root canals. For straight root canals, the combination of 1% SDSn and Gentlefile Brush can increase the clearance rate of Vitapex paste. For the middle and lower sections of curved root canals, the use of 1% SDSn in conjunction with the IrriFlex irrigation needle can effectively enhance the clearance rate of Vitapex paste.

Key words: root canal irrigation, vitapex paste, sodium dodecyl sulfonate, intracanal medication, curved root canals