title: [The effect of root canal preparation with nickel-titanium rotary instruments in reducing post-operative pain].
abstract: OBJECTIVE
  To examine the effect of nickel-titanium rotary instruments in reducing post-operative pain.
  
  
  METHODS
  95 molars with pulpal and/or periapical involvement were randomly assigned to two groups for root canal preparation. One group was treated with ProFile nickel-titanium rotary instruments; the other was treated by using stainless steel hand files-FlexoFile. The incidence and degree of post-operative pain after root canal preparation in the two groups were recorded.
  
  
  RESULTS
  In ProFile group, the incidence of post-operative pain was 27.7%, while 62.5% of the teeth developed post-operative pain after hand preparation. The difference between two groups was statistically significant (P < 0.01).
  
  
  CONCLUSIONS
  Root canal preparation on molars with stainless steel hand files resulted in relatively high incidence of post-operative pain. Mechanical preparation using ProFile nickel-titanium instruments generated less post-operative pain and discomfort.
authors.affiliation: Operative Dentistry and Endodontics, Guanghua College of Stomatology, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.forename: Zhengmei
authors.initials: Z
authors.lastname: Lin
authors.forename: Simin
authors.initials: S
authors.lastname: Peng
mesh_terms: D000328:Adult; D000368:Aged; D003755:Dental High-Speed Technique / Q000295:instrumentation*; D003762:Dental Instruments; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009532:Nickel; D010149:Postoperative Pain / Q000517:prevention & control*; D012189:Retrospective Studies; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium