title: Nanoleakage related to bond strength in RM-GIC and adhesive restorations.
abstract: OBJECTIVE
  This was to investigate the nanoleakage of Resin Modified Glass Ionomer Cement (RMGIC) and composite resin (CR) restorations in sound and caries-affected primary dentine, submitted to load cycling and cariogenic challenge in vitro.
  
  
  METHODS
  Occlusal cavities were prepared in 60 sound exfoliated primary second molars and 30 specimens were subjected to chemical induction of artificial caries lesions and the others were restored without caries induction. All prepared teeth were divided into 2 groups according to restorative materials. From each dentine condition 5 restored teeth and restorative material were subjected to microtensile bond strength and nanoleakage tests immediately or after load-cycling or submitted to the pH-cycling procedure before testing.
  
  
  RESULTS
  The adhesive presented bigger areas of silver leakage at the interfaces on caries-affected dentine (2.46±0.47)mm2 than sound dentine (0.90±0.19)mm2. RMGIC nanoleakage was not influenced by the sound (1.75±0.11)mm2 or caries-affected (2.08±0.39) condition of the substrate. A significant moderate inverse correlation was revealed between the bond strength and silver leakage area at the interface, (r= -0.55, p<0.001).
  
  
  CONCLUSIONS
  Nanoleakage is greater in caries-affected primary teeth dentine than sound dentine in adhesive restorations although at the interfaces of RMGIC does not differ. As nanoleakage increases, bond strength decreases significantly.
authors.affiliation: Federal University of Santa Maria, RS, Santa Maria, RS, 97015-372, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Marquezan
authors.forename: J A
authors.initials: JA
authors.lastname: Skupien
authors.forename: B L
authors.initials: BL
authors.lastname: da Silveira
authors.forename: A
authors.initials: A
authors.lastname: Ciamponi
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology* / Q000628:therapy; D003738:Dental Cements; D003763:Dental Leakage / Q000209:etiology*; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin / Q000473:pathology; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008963:Molar; D058608:Nanopores; D019279:Resin Cements; D012822:Silicon Dioxide; D012834:Silver; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D014094:Tooth, Deciduous; D015040:Zirconium
chemical_list: C554641:Adper single bond 2; D003188:Composite Resins; D003738:Dental Cements; D005899:Glass Ionomer Cements; D019279:Resin Cements; C084550:Vitremer; C083568:Z100 composite resin; C000212:ammoniacal silver; D012834:Silver; D012822:Silicon Dioxide; D015040:Zirconium