Abstract: Objective:To evaluate the clinical effects and reliability of one-visit endodontic therapy for infected root canals.Methods:One hundred and forty-two teeth with dental pulp necrosis or chronic periapical periodontitis were investigated.Eighty teeth(one-visit group)were treated with one-visit canal obturation,and 62 teeth(two-visit group)were treated with canal obturation after two-visit therapy,the first therapy of which was sealing the root canals using calcium hydroxide.The pre-and post-operative pain in 1 week of two groups were observed,the 2 years cure rate after operation of two groups were evaluated,and the clinical effects of two groups were compared.Results:The differences of pre-and post-operative pain in 1 week of two groups were not statistical significance(P0.05).The 2 years cure rate after operation of one and two-visit group were 92.8% and 90.2%,respectively.The differences of curative effects in two groups were not statistically significant(P0.05).Conclusions:Compared with two-visit therapy,the postoperative pain and 2 years cure rate of one-visit endodontic therapy for infected root canals has no significant difference and its pain period is short,and which has a certain clinical feasibility.