title: The effect of short polyethylene fiber with different weight percentages on diametral tensile strength of conventional and resin modified glass ionomer cements.
abstract: BACKGROUND
  The aim of this study was to investigate the effect of polyethylene fiber on diametral tensile strength of conventional and resin modified glass ionomer cements.
  
  
  METHODS
  60 specimens in 6 groups (n=10) were prepared. In group 1 conventional glass ionomer (Fuji GC) and in group 2 resin modified glass ionomer (Fuji LC) were as control groups. In group 3 and 4 conventional glass ionomers mixed with short polyethylene fibers in proportion of 1 wt% and 3 wt%, respectively. In fifth and sixth groups, resin modified glass ionomer and short polyethylene fibers were mixed in 1 and 3% wt, respectively. Samples were prepared in a round brass mold (6.5×2.5 mm). After thermo-cycling, the diametral tensile strength of the specimens were tested and data were analyzed with ANOVA and post-hoc tests (p<0.05).
  
  
  RESULTS
  Diametral tensile strength of both conventional and resin modified glass ionomer cements increased after mixing with polyethylene fiber (p<0.001). Also, reinforcement occurred as the mixing percentage increased from 1% wt to 3% wt in either conventional and resin modified glass ionomer (p<0.001).
  
  
  CONCLUSIONS
  The polyethylene fiber was shown to have a significant positive influence on diametral tensile strength of two types of glass ionomers.Key words:Conventional glass ionomer, diametral tensile strength, polyethylene fiber, resin modified glass ionomer.
authors.affiliation: Professor, Department of Operative Dentistry, Biomaterial Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Farahnaz
authors.initials: F
authors.lastname: Sharafeddin
authors.affiliation: Dentist, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Seyed-Ali
authors.initials: SA
authors.lastname: Ghaboos
authors.affiliation: Assistant professor, Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Jowkar