title: Bonding of simplified adhesive systems to caries-affected dentin of primary teeth.
abstract: OBJECTIVE
  To evaluate the bonding of simplified adhesive systems to sound and caries-affected dentin of primary teeth with microtensile (µTBS) and nanoleakage (NL) tests.
  
  
  METHODS
  Occlusal cavities were prepared in 36 sound second primary molars. Half of the specimens were submitted to pH cycling to simulate caries-affected dentin. Teeth were randomly restored with one of three materials: the etch-and-rinse adhesive system Adper Single Bond 2 (SB), the two-step self-etching adhesive system Adper SE Plus (SE), and the one-step self-etching adhesive system Adper Easy One (EASY). After storage for 24 h, specimens with cross-sectional areas of 0.8 mm2 were prepared for microtensile testing (1 mm/min). One stick from each tooth was immersed in silver nitrate solution (24 h) and allowed to develop for 8 h in order to score the nano leakage with SEM. The fracture pattern was evaluated using a stereomicroscope (400X). The µTBS means were analyzed by two-way ANOVA and Tukey's post-hoc test. For NL, the Kruskal- Wallis and Mann-Whitney tests were used (α < 0.05).
  
  
  RESULTS
  SB (35.5 ± 3.5) showed the highest µTBS value to sound dentin, followed by EASY (26.3 ± 1.9) and SE (18.2 ± 6.5) (p < 0.05). No difference among materials was observed for caries-affected dentin (SB: 17.8 ± 4.2; SE: 13.9 ± 3.2; EASY: 14.4 ± 4.2, p > 0.05). For all groups, adhesive/mixed fracture prevailed. Caries affected dentin promoted silver nitrate uptake into the adhesive interface; however, with SE, the nano leakage was more pronounced than in the other adhesive systems, even in sound dentin.
  
  
  CONCLUSIONS
  Caries-affected dentin negatively influences the bond strength and nano leakage of the two-step etch-and-rinse and one-step self-etching adhesive systems tested in primary teeth.
authors.forename: Fabiana Bucholdz
authors.initials: FB
authors.lastname: Alves
authors.forename: Tathiane Larissa
authors.initials: TL
authors.lastname: Lenzi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Thiago Saads
authors.initials: TS
authors.lastname: Carvalho
authors.forename: Daniela Prócida
authors.initials: DP
authors.lastname: Raggio
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000145:classification; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000473:pathology*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000473:pathology; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D016622:Silver Staining; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014094:Tooth, Deciduous / Q000473:pathology*
chemical_list: C554641:Adper single bond 2; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate