title: Bacteriemia during endodontic treatment in relation to the technique of biomechanical preparation: randomized clinical trial.
abstract: OBJECTIVE
  The aim of this randomized clinical trial was to evaluate the frequency of bacteriemia during endodontic treatment, with comparison between two techniques for biomechanical preparation of the root canal system.
  
  
  METHODS
  The sample comprised 50 patients aged 16 to 52 years, of both genders, which were divided into 2 groups with 25 patients each. Group I underwent biomechanical preparation by the step-back technique, and Group II was treated by the rotary technique with nickel-titanium instruments (K3). Patients were submitted to antisepsis of the oral cavity with chlorhexidine digluconate and three samples of blood were collected for blood culture: preoperatively, immediately after the biomechanical preparation and 10 minutes later. The significance level adopted was 5.0%, and analysis was performed by descriptive and inferential statistics by means of the Fisher's exact test, Fisher-Freeman-Halton test and Student's t test. Data were analyzed on the Statexact and SPSS softwares.
  
  
  RESULTS
  All blood cultures achieved before and immediately after preparation were negative. On the other hand, with regard to the blood cultures collected 10 minutes after preparation, one (4%) positive case was found for Group I. However, this difference was not statistically significant (p = 0.50).
  
  
  CONCLUSIONS
  The frequency of bacteriemia was low and observed just for Group I.
authors.affiliation: Department of Public Health Dentistry, Dental School, University of Pernambuco, Brazil. adriane@hotlink.com.br
authors.forename: Adriane Tenório
authors.initials: AT
authors.lastname: Dourado
authors.forename: Arnaldo de França
authors.initials: Ade F
authors.lastname: Caldas Junior
authors.forename: Diógenes Ferreira
authors.initials: DF
authors.lastname: Alves
authors.forename: Creso Abreu
authors.initials: CA
authors.lastname: Falcão