title: Effect of dentinal water on bonding of self-etching adhesives.
abstract: This study examined the effect of dentinal water on bonding, comparing one-bottle and two-step self-etching adhesives using microtensile bond test and scanning electron microscope. The bond strength of resin to dentin was measured for wet dentin (control) and dry dentin substrates. Wet dentin is the normal substrate for bond testing, whereas dry dentin was dehydrated in a desiccator at different drying times (5 to 60 min) before bonding. After bond testing, the fractured surfaces were examined. Although no correlation was found for two-step self-etching adhesives, the bond strength of the dry-dentin was significantly increased with the increase in the drying-time for one-bottle adhesives. With increased drying-time, the amount of water-bubbles was decreased for one-bottle adhesives; however, no bubble formation was seen in two-step adhesives in any group. The hydrophilic resin adhesive may entrap the water from dentin by osmosis during and after bonding. This effect may depend on the "hydrophilicity" of adhesives.
authors.affiliation: Division of Biomaterials and Bioengineering, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan. masanori-h@mue.biglobe.ne.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Shinichi
authors.initials: S
authors.lastname: Fujita
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Endo
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohno
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001834:Body Water / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003763:Dental Leakage / Q000517:prevention & control; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D003804:Dentin / Q000737:chemistry* / Q000187:drug effects; D017220:Dentin-Bonding Agents / Q000737:chemistry* / Q000494:pharmacology; D003890:Desiccation; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008689:Methacrylates / Q000737:chemistry*; D008964:Molar, Third; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011109:Polymethacrylic Acids; D019279:Resin Cements; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate