title: Bonding effectiveness of two contemporary self-etch adhesives to enamel and dentin.
abstract: OBJECTIVE
  Among contemporary adhesives, self-etch adhesives have been adopted by general practitioners for routine adhesive restorative purposes, mainly because of their ease of use. However, many versions that differ for their clinical application procedure, pH, number of components, etc., are currently available on the market. The purpose of this study was to determine the bonding effectiveness of two new self-etch adhesives (Adper Easy Bond and Adper ScotchBond SE, 3M ESPE) to enamel and dentin using a micro-tensile bond strength (microTBS) protocol and to characterise the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM).
  
  
  METHODS
  The adhesives were applied onto coronal human enamel and dentin surfaces and built up with the micro-hybrid resin composite Z100 (3M ESPE). The 'gold-standard' two-step self-etch adhesive Clearfil SE Bond (Kuraray) served as control. Specimens were sectioned to sticks and trimmed at the interface to a cylindrical hour-glass shape ('trimmed' micro-specimens). Non-demineralized and demineralized TEM sections through the adhesive-dentin/enamel interface were prepared by ultra-microtomy.
  
  
  RESULTS
  The microTBS of the two self-etch adhesives to enamel was statistically significantly lower than that of the control. To dentin, the microTBS of Adper Easy Bond was significantly lower than that of Adper ScotchBond SE and the control. TEM showed a tight interface to enamel for all three self-etch adhesives. A relatively thick, completely demineralized and acid-resistant hybrid layer was formed at dentin by Adper ScotchBond SE, whereas the interaction of Adper Easy Bond was much shallower, and comparable to that of so-called 'ultra-mild' self-etch adhesives. Some degree of spot- and cluster-like nano-leakage was observed for both adhesives, but did not differ in extent and form from that observed for the control.
  
  
  CONCLUSIONS
  Although the new two self-etch adhesives revealed a tight interaction at both enamel and dentin, their bond strength to both tooth tissues was generally lower than that of the control adhesive. Nevertheless, their bonding effectiveness appears in line with other simplified self-etch adhesives.
authors.affiliation: Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Leuven, Belgium.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mine
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.forename: Marcio V
authors.initials: MV
authors.lastname: Cardoso
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Van Landuyt
authors.forename: André
authors.initials: A
authors.lastname: Poitevin
authors.forename: Takuo
authors.initials: T
authors.lastname: Kuboki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Paul
authors.initials: P
authors.lastname: Lambrechts
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D001840:Dental Bonding; D003743:Dental Enamel; D045662:Dental Etching / Q000379:methods; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D008964:Molar, Third; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D019279:Resin Cements