RESUMO
BACKGROUND:For on-visit root canal therapy, ultrasound washing can improve the quality of root canal irrigation, and play a synergistic role with ultrasound so that the flushing fluid can reach the area that cannot be completely cleaned up by root canal preparation instruments, such as apical isthmus and col ateral root canal, for removal of the detritus, cleanup and disinfection. ＜br> OBJECTIVE:To evaluate the clinical effect of one-visit root treatment with nickel-titanium rotary instruments and ultrasonic irrigation unit in treatment of chronic apical periodontitis. ＜br> METHODS:A total of 460 patients with il ed 460 teeth were selected. Patients were randomly divided into three groups:Mtwo instrument and ultrasonic technique combined with sodium hypochlorite was utilized in group A;ultrasonic technique combined with active silver ion antibacterial solution was utilized in group B;stainless steel K files with saline and hydrogen peroxide solution were used as irrigations in group C. Twenty-four hours after root canal fil ing, the pain degree was self-assessed by patients with visual analogue scale, and subsequent visit was done 7 days after root canal fil ing. Six and twelve months after root canal fil ing, the therapeutic effect was determined with X-ray examination and clinical assessment. ＜br> RESULTS AND CONCLUSION:The degree of pain and occurrence rate of acute reactions in groups A and B were significantly lower than those in group C (P＜0.05), but there was no significant difference between groups A and B (P>0.05). Six months after root canal fil ing, the cure rate was not significantly different between three groups (P>0.05). But after 12 months, the cure rate in the group C was significantly lower than that in groups A and B (P＜0.05). By using of nickel-titanium rotary instruments and ultrasonic irrigation unit in treatment of chronic apical periodontitis, the short-and long-term effects of one-visit root treatment have been achieved clinical y.
