title: Effect of partially demineralized dentin beneath the hybrid layer on dentin-adhesive interface micromechanics.
abstract: OBJECTIVE
  To investigate the presence of non-infiltrated, partially demineralized dentin (PDD) beneath the hybrid layer for self-etch adhesive systems, and its effect on micromechanical behavior of dentin-adhesive interfaces (DAIs). This in-vitro laboratory and computer simulation study hypothesized that the presence of non-infiltrated PDD beneath the hybrid layer does not influence the mechanical behavior of the DAI of self-etch adhesive systems.
  
  
  METHODS
  Fifteen sound third molars were restored with composite resin using three adhesive systems: Scotchbond Multipurpose (SBMP), Clearfil SE Bond (CSEB) and Adper Promp L-Pop (APLP). The thickness and length of all DAIs were assessed using scanning electron microscopy, and used to generate three-dimensional finite element models. Elastic moduli of the hybrid layer, adhesive layer, intertubular dentin, peritubular dentin and resin tags were acquired using a nano-indenter. Finite element software was used to determine the maximum principal stress. Mixed models analysis of variance was used to verify statistical differences (P<0.05).
  
  
  RESULTS
  Elastic moduli and morphology were found to differ between the adhesive systems, as well as the presence and extension of PDD.
  
  
  CONCLUSIONS
  Both self-etch adhesive systems (APLP and CSEB) had PDD. The DAI stress levels were higher for the one-step self-etch adhesive system (APLP) compared with the etch-and-rinse adhesive system (SBMP) and the self-etch primer system (CSEB).
authors.affiliation: Department of Dental Materials and Prosthodontics, Sao Paulo State University, Araçatuba Dental School, Araçatuba, SP, Brazil; New York University, College of Dentistry, Epidemiology and Health Promotion, New York, NY, USA. Electronic address: rodolfoanchieta2@hotmail.com.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Bruniera Anchieta
authors.affiliation: Department of Restorative Dentistry, Sao Paulo State University, Araçatuba Dental School, Araçatuba, SP, Brazil; New York University, College of Dentistry, Epidemiology and Health Promotion, New York, NY, USA.
authors.forename: Lucas
authors.initials: L
authors.lastname: Silveira Machado
authors.affiliation: Department of Restorative Dentistry, Sao Paulo State University, Araçatuba Dental School, Araçatuba, SP, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Herman Sundfeld
authors.affiliation: Department of Operative Dentistry, School of Dentistry, University of Guarulhos, Guarulhos, SP, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Figueiredo Reis
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
authors.affiliation: Universidade Tecnológica Federal do Paraná, Curitiba, Brazil.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Luersen
authors.affiliation: New York University, College of Dentistry, Department of Biomaterial and Biomimetics, New York, NY, USA.
authors.forename: Malvin
authors.initials: M
authors.lastname: Janal
authors.affiliation: Department of Dental Materials and Prosthodontics, Sao Paulo State University, Araçatuba Dental School, Araçatuba, SP, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Passos Rocha
authors.affiliation: New York University, College of Dentistry, Epidemiology and Health Promotion, New York, NY, USA.
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
mesh_terms: D000269:Adhesives; D001696:Biomechanical Phenomena / Q000502:physiology; D017438:Bisphenol A-Glycidyl Methacrylate; D003198:Computer Simulation; D059605:Dental Implant-Abutment Design; D003804:Dentin / Q000502:physiology* / Q000648:ultrastructure*; D020342:Finite Element Analysis; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010755:Organophosphates; D019279:Resin Cements; D013314:Stress, Mechanical
chemical_list: D000269:Adhesives; C489661:Adper Prompt Self-Etch; C438313:Clearfil SE Bond; C093073:Demineralized Dentin Matrix; D010755:Organophosphates; D019279:Resin Cements; D017438:Bisphenol A-Glycidyl Methacrylate; C041330:Scotchbond
keywords: Adhesion; Adhesive systems; Dentin; Finite element; Hybrid layer; Mechanical properties; Nano-indentation