title: [Clinical study on the effects of single visit root canal treatment of chronic periapical periodontitis by two kinds of root canal preparation instruments system].
abstract: OBJECTIVE
  To investigate the different incidence of postoperative pain and long-term follow-up curative effects in patients with chronic periapical periodontitis undergoing single visit root canal treatment by two kinds of canal preparation instruments system.
  
  
  METHODS
  Ninety-eight permanent teeth with chronic periapical periodontitis were divided into two groups randomly. One group was prepared with nickel-titanium instruments, the other group was prepared with K files. After canal preparation, all the teeth underwent canal filling immediately. The different incidence of postoperative pain and long-term follow-up curative effects were recorded. Statistical analysis was carried out using SPSS13.0 software package.
  
  
  RESULTS
  One week after treatment, the rate of serious symptom of periapical periodontitis in the Ni-Ti group was less than that in the K file group (P<0.05 ). 18 months after treatment, the curative effect of two groups had no significant difference (P>0.05 ).
  
  
  CONCLUSIONS
  Nickel-titanium instrument used in treatment of chronic periapical periodontitis lead to less serious postoperative reaction than K file instruments, but the same long-term follow-up curative effects as K file instruments. Nickel-titanium instruments system is worthy of wide application in patients with chronic periapical periodontitis undergoing single visit root canal treatment.
authors.affiliation: Department of General Dentistry, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. whisper_zzj@msn.com
authors.forename: Zhuo-jun
authors.initials: ZJ
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: He
mesh_terms: D003786:Dental Pulp Cavity; D006801:Humans; D009532:Nickel; D010485:Periapical Periodontitis; D010518:Periodontitis; D011897:Random Allocation; D018915:Root Canal Preparation; D012390:Root Canal Therapy; D014025:Titanium
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium