title: Microleakage of Class V composites using different placement and curing techniques: an in vitro study.
abstract: OBJECTIVE
  To evaluate microleakage at enamel and dentin margins of two composite resins, using bulk and incremental placement techniques, "rebonding", and facial and lingual curing methods.
  
  
  METHODS
  One hundred standardized Class V cavity preparations were made on the facial surface of extracted human premolars and were randomly assigned to 10 groups. Single Bond was used as the dentin/enamel adhesive. A heavily filled composite resin, Z250, and a microfill, Silux Plus, were inserted and polymerized using five different techniques: (1) incremental placement and facial curing; (2) incremental placement, facial curing and rebonding; (3) bulk placement and facial curing; (4) bulk placement, facial curing and rebonding; (5) incremental placement and lingual and facial curing. After the restorations were finished and polished, the margins of those in the rebonded groups were etched, rinsed, and dried. The adhesive resin, Single Bond, was applied at the composite resin-tooth interface and light-cured. All the specimens were thermocycled, stained with 1% methylene blue, sectioned, and evaluated for leakage (0-4 scale) by two examiners.
  
  
  RESULTS
  Almost no leakage occurred at enamel margins. At the cementum margins, differences in microleakage related to restorative material or technique were not statistically significant. However, leakage at the cementum margins was significantly greater than at the enamel margins for both composite resin materials.
authors.affiliation: Department of Restorative Dentistry, University of Montreal, Quebec, Canada.
authors.forename: Annie J
authors.initials: AJ
authors.lastname: St Georges
authors.forename: Aldridge D
authors.initials: AD
authors.lastname: Wilder
authors.forename: Jorge
authors.initials: J
authors.lastname: Perdigão
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Swift
mesh_terms: D001641:Bicuspid; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D001840:Dental Bonding; D003739:Dental Cementum; D003743:Dental Enamel; D003763:Dental Leakage / Q000517:prevention & control*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods*; D017220:Dentin-Bonding Agents; D006801:Humans; D011897:Random Allocation; D019237:Tooth Cervix
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; C115612:single bond; C074741:Silux Plus; D017438:Bisphenol A-Glycidyl Methacrylate