title: The effect of two different polishing techniques on microleakage of new composites in Class V restorations.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of polishing systems on the microleakage of a nanofill, a nanohybrid, and a microhybrid composite in Class V cavities.
  
  
  METHODS
  Preparations were made at the cemento-enamel junction (CEJ) of 36 extracted human premolars. The teeth were randomly divided into three groups and restored with new resin composites according to the manufacturers' instructions as follows: Group 1, Filtek Supreme & Single Bond; Group 2, Grandio & Solobond; and Group 3, Artemis & Excite. The restorations were finished with diamond finishing burs. The restored/finished teeth were randomly divided into two groups and polished using the following systems: Super-Snap (Al2O2 coated, abrasive disc system, fine grit, and extra fine grit) and Astropol/Astrobrush (silicon-based abrasive polisher point and polisher brush). All specimens were thermocycled 1000 times with a 10 second dwell time. They were immersed in 0.5% aqueous basic fuchsin dye for 24 hours and then sectioned buccal-lingual-longitudinally through the center of both restorations of each tooth and evaluated under a stereomicroscope at 30X magnification. The degree of dye penetration was quantified.
  
  
  RESULTS
  No significant difference in leakage scores was observed in enamel margins (p=0.456, Kruskall Wallis test), but dentin margins were significantly affected by the different polishing systems (p=0.037, Kruskall Wallis test). The lower leakage scores were recorded for Astropol/Astrobrush polishing systems. The nanofill composite showed the least leakage among the test groups in this study. The most leakage was observed in nanohybrid composite resin (p<0.05, Mann Whitney U test).
  
  
  CONCLUSIONS
  Under the conditions of this in vitro study: the microleakage resistance of composites at enamel margins is not significantly affected by the different polishing systems; the lowest leakage scores were recorded for Astropol/Astrobrush polishing techniques in different types of composites; and the ranking of the composite materials from most to least leakage at the dentin margins according to polishing techniques was Grandio >Artemis > Filtek Supreme.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Hacettepe University, Ankara, Turkey. fyalcin@hacettepe.edu.tr
authors.forename: Filiz
authors.initials: F
authors.lastname: Yalçin
authors.forename: Yonca
authors.initials: Y
authors.lastname: Korkmaz
authors.forename: Meserret
authors.initials: M
authors.lastname: Başeren
mesh_terms: D001641:Bicuspid; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D003737:Dental Cavity Preparation; D003763:Dental Leakage / Q000517:prevention & control*; D018772:Dental Marginal Adaptation; D003775:Dental Polishing / Q000379:methods*; D003793:Dental Restoration, Permanent; D017220:Dentin-Bonding Agents; D006801:Humans; D008689:Methacrylates; D053761:Nanocomposites; D010316:Particle Size; D019279:Resin Cements; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C420130:Excite cement; C474035:Filtek Supreme; C509998:Grandio; D008689:Methacrylates; D019279:Resin Cements; C488002:Solobond Plus adhesive; C515215:artemis composite resin; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate