title: Correlation between degree of conversion, resin-dentin bond strength and nanoleakage of simplified etch-and-rinse adhesives.
abstract: OBJECTIVE
  The aim of this study was to correlate the degree of conversion measured inside the hybrid layer (DC) with the microtensile resin-dentin bond strength (μTBS) and silver nitrate uptake or nanoleakage (SNU) for five simplified etch-and-rinse adhesive systems.
  
  
  METHODS
  Fifty-five caries free extracted molars were used in this study. Thirty teeth were used for μTBS/SNU [n=6] and 25 teeth for DC [n=5]. The dentin surfaces were bonded with the following adhesives: Adper Single Bond 2 (SB), Ambar (AB), XP Bond (XP), Tetric N-Bond (TE) and Stae (ST) followed by composite resin build-ups. For μTBS and SNU test, bonded teeth were sectioned in order to obtain stick-shaped specimens (0.8mm(2)), which were tested under tensile stress (0.5mm/min). Three bonded sticks, from each tooth, were not tested in tensile stress and they were immersed in 50% silver nitrate, photo-developed and analyzed by scanning electron microscopy. Longitudinal 1-mm thick sections were prepared for the teeth assigned for DC measurement and evaluated by micro-Raman spectroscopy.
  
  
  RESULTS
  ST showed lowest DC, μTBS, and higher SNU (p<0.05). All other adhesives showed similar DC, μTBS, and SNU (p>0.05), except for TE which showed an intermediate SNU level. The DC was positively correlated with μTBS and negatively correlated with SNU (p<0.05). SNU was also negatively correlated with μTBS (p<0.05).
  
  
  CONCLUSIONS
  The measurement of DC inside the hybrid layer can provide some information about bonding performance of adhesive systems since this property showed a good correlation with resin-dentin bond strength and SNU values.
authors.affiliation: Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil.
authors.forename: Viviane
authors.initials: V
authors.lastname: Hass
authors.forename: Max
authors.initials: M
authors.lastname: Dobrovolski
authors.forename: Christiana
authors.initials: C
authors.lastname: Zander-Grande
authors.forename: Gislaine Cristine
authors.initials: GC
authors.lastname: Martins
authors.forename: Luís Alfonso Arana
authors.initials: LA
authors.lastname: Gordillo
authors.forename: Maria de Lourdes
authors.initials: Mde L
authors.lastname: Rodrigues Accorinte
authors.forename: Osnara Maria Mongruel
authors.initials: OM
authors.lastname: Gomes
authors.forename: Alessandro Dourado
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000145:classification*; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D058105:Polymerization; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D016622:Silver Staining; D013059:Spectrum Analysis, Raman; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: C554641:Adper single bond 2; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; C403634:Stae bonding agent; C532387:XP-Bond; C029824:urethane dimethacrylate luting resin; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate
keywords: Degree of conversion; Dentin bonding systems; Hybrid layer; Raman spectroscopy