title: Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method.
abstract: OBJECTIVE
  The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration.
  
  
  METHODS
  For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05).
  
  
  RESULTS
  In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study.
  
  
  CONCLUSIONS
  Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics.
authors.affiliation: DDS, MSc, Associate Professor. Department of Endodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tabrizizadeh
authors.affiliation: DDS, MSc, Assistant Professor. Department of Endodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Kazemipoor
authors.affiliation: DDS, MSc, Associate Professor. Department of Surgical and Clinical Pathology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Seyed-Hossein
authors.initials: SH
authors.lastname: Hekmati-Moghadam
authors.affiliation: MA, Librarian and search literature officer. Department of Endodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Roqayeh
authors.initials: R
authors.lastname: Hakimian