title: Behavior of failed bonded interfaces under in vitro cariogenic challenge.
abstract: OBJECTIVE
  This in vitro study aimed to compare dentin wall caries development at different composite-dentin interfaces.
  
  
  METHODS
  Dentin samples (10.4 mm(2)) were restored with composite resin using two adhesive systems (etch-and-rinse and self-etch techniques). Different composite-dentin interfaces with gaps were produced: (a) failed bonded, which were fractured at interface after being submitted to aging protocols (no aging, mechanical loading or water storage); (b) non-bonded interfaces, both without any adhesive material or with adhesive material applied only on the dentin. Adhesively fractured and non-bonded samples were subjected to a lactic acid gel (pH=5) caries model with a continuous opening/closing movement of the interfacial gap for 10 days. Transverse wavelength-independent microradiographs were taken, and lesion depth and mineral loss were measured. Data were analyzed with linear mixed-effects regression models.
  
  
  RESULTS
  Caries development differed among the composite-dentin interfaces (p<0.001). The non-bonded interface with adhesive material on the dentin showed less lesion depth than the failed bonded groups, while the non-bonded interface without adhesive on dentin showed the deepest wall lesions. Difference between the adhesive systems was observed only in the non-bonded groups (p=0.003), with the self-etch adhesive applied on the dentin showing more severe lesions. Samples broken after mechanical loading aging showed deeper lesions than those broken after water storage (p<0.001).
  
  
  CONCLUSIONS
  Composite-dentin interfaces failed after aging presented different demineralization from interfaces that were never bonded, indicating that the restorative treatment changes the tissue in a way relevant to secondary caries development.
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, Federal University of Pelotas, Gonçalves Chaves 457, 96015-560 Pelotas, RS, Brazil; College of Dental Sciences, Department of Preventive and Restorative Dentistry, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, The Netherlands. Electronic address: animontag@gmail.com.
authors.forename: Anelise F
authors.initials: AF
authors.lastname: Montagner
authors.affiliation: College of Dental Sciences, Department of Preventive and Restorative Dentistry, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, The Netherlands.
authors.forename: Niek J M
authors.initials: NJ
authors.lastname: Opdam
authors.affiliation: College of Dental Sciences, Department of Preventive and Restorative Dentistry, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, The Netherlands.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Ruben
authors.affiliation: College of Dental Sciences, Department of Preventive and Restorative Dentistry, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, The Netherlands.
authors.forename: Ewald M
authors.initials: EM
authors.lastname: Bronkhorst
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, Federal University of Pelotas, Gonçalves Chaves 457, 96015-560 Pelotas, RS, Brazil.
authors.forename: Maximiliano S
authors.initials: MS
authors.lastname: Cenci
authors.affiliation: College of Dental Sciences, Department of Preventive and Restorative Dentistry, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, The Netherlands.
authors.forename: Marie-Charlotte D N J M
authors.initials: MC
authors.lastname: Huysmans
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins; D001840:Dental Bonding; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements
keywords: Adhesive interface; Aging; Cariogenic challenge; Dental bonding; Dental caries; Dentin bonding; Failure; Fracture; Secondary caries; Tooth demineralization