title: Effect of smear layer deproteinizing on resin-dentine interface with self-etch adhesive.
abstract: OBJECTIVE
  This study aimed to investigate deproteinizing effect of sodium-hypochlorite (NaOCl) and mild acidic hypochlorous-acid (HOCl) pretreatment on smear layer-covered dentine and to evaluate their effects on morphological characteristics of resin-dentine interface with self-etch adhesive.
  
  
  METHODS
  Human coronal-dentine discs with standardized smear layer were pretreated with 6% NaOCl or 50ppm HOCl for 15s or 30s. Their deproteinizing effects at the treated smear layer-covered dentine surfaces were determined by the measurement of amide:phosphate ratio using ATR-FTIR analysis. In addition, using TEM, micromorphological alterations of hybridized complex and nanoleakage expression were evaluated at the interface of a self-etch adhesive (Clearfil SE Bond) to the pretreated dentine surface with or without subsequent application of a reducing agent (p-Toluenesulfinic acid salt; Accel(®)).
  
  
  RESULTS
  Both pretreatments of NaOCl and HOCl significantly reduced the amide:phosphate ratio as compared with the no-pretreated group (p<0.05), coincident with the elimination of the hybridized smear layer on their bonded interfaces. Nanoleakage within the hybrid layer was found in the no-pretreated and NaOCl-pretreated groups, whereas the subsequent reducing agent application changed the reticular nanoleakage to spotted type. HOCl-pretreated groups showed less nanoleakage expression in a spotted pattern, regardless of reducing agent application.
  
  
  CONCLUSIONS
  NaOCl and HOCl solutions could remove the organic component on the smear layer-covered dentine, which could eliminate the hybridized smear layer created by self-etch adhesive, leading to the reduction of nanoleakage expression within hybrid layer.
  
  
  CONCLUSIONS
  Smear layer deproteinizing could modify dentine surface, giving an appropriate substrate for bonding to self-etch adhesive system.
authors: Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors: Ornnicha
authors: O
authors: Thanatvarakorn
authors: Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: nakajima.ope@tmd.ac.jp.
authors: Masatoshi
authors: M
authors: Nakajima
authors: Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, Chiang Mai University, T. Suthep, A. Muang, Chiang Mai 50200, Thailand.
authors: Taweesak
authors: T
authors: Prasansuttiporn
authors: Instrumental Analysis Research Center, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors: Shizuko
authors: S
authors: Ichinose
authors: Division of Conservative Dentistry, King's College London Dental Institute at Guy's, King's and St Thomas' Hospitals, King's College London, Floor 25, London Bridge, London SE1-9RT, UK.
authors: Richard M
authors: RM
authors: Foxton
authors: Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors: Junji
authors: J
authors: Tagami
mesh_terms: D000577:Amides / Q000032:analysis; D003094:Collagen / Q000032:analysis; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003763:Dental Leakage / Q000145:classification; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D006997:Hypochlorous Acid / Q000627:therapeutic use*; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D010710:Phosphates / Q000032:analysis; D011897:Random Allocation; D019163:Reducing Agents / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D016369:Smear Layer / Q000188:drug therapy* / Q000473:pathology; D012973:Sodium Hypochlorite / Q000627:therapeutic use*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013997:Time Factors; D014050:Toluene / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D000577:Amides; C438313:Clearfil SE Bond; D003188:Composite Resins; D003764:Dental Materials; D010710:Phosphates; D019163:Reducing Agents; D019279:Resin Cements; D012388:Root Canal Irrigants; D014050:Toluene; D006997:Hypochlorous Acid; D003094:Collagen; D012973:Sodium Hypochlorite; C065428:4-toluenesulfinic acid
keywords: Attenuated total reflection Fourier transform infrared; Hybridized smear layer; Hypochlorous-acid; Nanoleakage; Smear layer deproteinizing; Sodium-hypochlorite