title: Assessing microleakage in resin composite restorations rebonded with a surface sealant and three low-viscosity resin systems.
abstract: OBJECTIVE
  The aim of this study was to assess the ability of three low-viscosity resin systems (Unibond, Single Bond, and Fluorseal), used as rebonding agents, and a specific surface-penetrating sealant (Fortify) to prevent microleakage in Class V resin composite restorations.
  
  
  METHODS
  Fifty Class V cavities with the occlusal margin in enamel and the cervical margin in dentin and cementum were prepared on both the buccal and lingual surfaces of sound extracted premolars and restored with a hybrid light-cured resin composite. After finishing and polishing, restorations were randomly assigned to one of five equal groups (n = 10): a control, without surface sealing, and four experimental groups in which margins were etched and rebonded. Specimens were thermocycled, immersed in a 50% silver nitrate solution, sectioned longitudinally, and analyzed for leakage at the occlusal and cervical interfaces.
  
  
  RESULTS
  Statistical analysis showed significantly less leakage at the enamel margins for all groups. Fortify and Unibond were statistically similar and provided better marginal sealing at dentin and cementum interfaces. Fluorseal showed the poorest ability to prevent microleakage.
  
  
  CONCLUSIONS
  The rebonding technique may substantially minimize microleakage at dentin and cementum margins of composite restorations, when a resin system with sufficiently low viscosity is used as a surface sealant, regardless of whether it has been specified for such a purpose.
authors.affiliation: Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Av do Café, s/n Monte Alegre CEP: 14040-904, Ribeirão Preto, São Paulo, Brasil. rgpalma@forp.usp.br
authors.forename: Renata Pereira
authors.initials: RP
authors.lastname: Ramos
authors.forename: Michelle Alexandra
authors.initials: MA
authors.lastname: Chinelatti
authors.forename: Daniela Thomazatti
authors.initials: DT
authors.lastname: Chimello
authors.forename: Regina Guenka Palma
authors.initials: RG
authors.lastname: Dibb
mesh_terms: D000134:Acid Etching, Dental; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003739:Dental Cementum / Q000648:ultrastructure; D003743:Dental Enamel / Q000648:ultrastructure; D003763:Dental Leakage / Q000145:classification*; D003775:Dental Polishing; D003793:Dental Restoration, Permanent / Q000145:classification; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D010895:Pit and Fissure Sealants / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D016622:Silver Staining; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013816:Thermodynamics; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C095811:Fortify sealant; C092987:Optibond; D010895:Pit and Fissure Sealants; C099128:Prodigy; D019279:Resin Cements; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate