title: Dentin bonding performance and ability of four MMA-based adhesive resins to prevent demineralization along the hybrid layer.
abstract: OBJECTIVE
  To evaluate the tensile bond durability and ability of four MMA-based adhesive resins to prevent demineralization along the hybrid layer when exposed to a demineralizing solution.
  
  
  METHODS
  A PMMA rod was bonded to human dentin using one of four MMA-based adhesive systems: Super-Bond C&B (SB), SBP-40TX (SBP, experimental), M-Bond (MB), and M-Bond II (MB II). Bonded specimens were sectioned into 0.9 mm x 0.9 mm beams and subjected to microtensile bond strength (µTBS) testing after water storage at 37°C for 24 h or 10,000 thermal cycles. Data were analyzed with two-way ANOVA and Bonferroni's t-test. Fracture mode analysis of the bonding interface was performed using a scanning electron microscope (SEM) and statistically analysed using the chi-square test. To disclose the demineralization inhibition potential through formation of an acid-base resistant zone (ABRZ), the bonded interface was exposed to a demineralizing solution (pH 4.5) for 90 min, and then 5% NaOCl for 20 min. After argon-ion etching, the interfacial ultrastructure was observed using an SEM.
  
  
  RESULTS
  µTBS values without thermocycling were not significantly different (p > 0.05) among 4 adhesive resins. After thermocycling, a significant decrease in µTBS was found in MB and MB II (p < 0.001), whereas SB and SBP showed no significant change (p > 0.05). Failure modes were significantly different (p < 0.05). An ABRZ was seen in SBP, MB, and MB II, while this protective zone was absent in SB.
  
  
  CONCLUSIONS
  Dentin bonding performance after thermocycling was material dependent in MMA-based adhesive resins. The ABRZ formation was only observed in the self-etching systems.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hamid
authors.initials: H
authors.lastname: Nurrohman
authors.forename: Toru
authors.initials: T
authors.lastname: Nikaido
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takagaki
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadr
authors.forename: Kanchana
authors.initials: K
authors.lastname: Waidyasekera
authors.forename: Shuzo
authors.initials: S
authors.lastname: Kitayama
authors.forename: Masaomi
authors.initials: M
authors.lastname: Ikeda
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D001896:Boron Compounds / Q000737:chemistry; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate / Q000737:chemistry*; D008768:Methylmethacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D058626:Plasma Gases / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012973:Sodium Hypochlorite / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D017001:Tooth Demineralization / Q000503:physiopathology; D014867:Water / Q000737:chemistry
chemical_list: D001896:Boron Compounds; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D008768:Methylmethacrylates; D058626:Plasma Gases; D011140:Polyurethanes; D019279:Resin Cements; D014867:Water; C029824:urethane dimethacrylate luting resin; D020366:Methylmethacrylate; C005044:hydroxyethyl methacrylate; C034139:4-methacryloxyethyltrimellitic acid anhydride; D019904:Polymethyl Methacrylate; C049495:Super-bond; D012973:Sodium Hypochlorite