title: Effects of a self-etching primer on enamel shear bond strengths and SEM morphology.
abstract: OBJECTIVE
  To study a dental adhesive system containing a self-etching primer, by evaluating the enamel shear bond strengths and comparing the SEM interfacial morphology.
  
  
  METHODS
  100 flat enamel bonding sites were prepared to 600-grit on proximal surfaces of caries-free human molars. The bonding surfaces were treated with Clearfil Liner Bond 2 as recommended by the manufacturer, or combined with various acidic etchants. A composite rod (Clearfil Photo Anterior) was applied to the bonding area in two increments in a Teflon mold and polymerized for 100 s. After 24 h of water storage, the specimens were thermocycled and the shear bond strengths measured using an Instron testing machine. Forty extra molar crowns were roughened and treated with Clearfil Liner Bond 2 and alternative etchants, as described. A low-viscosity resin was bonded to the occlusal surfaces of these crowns, which were further demineralized and deproteinized. Field-Emission SEM examinations were carried out to evaluate the effects of different treatments on enamel surfaces.
  
  
  RESULTS
  The mean shear bond strengths were in the range of 18.1 MPa to 25.9 MPa, without significant differences between pairs of means. The failures were predominantly of the adhesive type. The use of alternative etchants resulted in the deepest etching patterns. The use of Clearfil Liner Bond 2, according to manufacturer's directions, resulted in a poorly-defined etching pattern. Regardless of the alternative etchant used, the use of the self-etching primer did not affect the mean enamel shear bond strength.
authors.affiliation: Department of Operative Dentistry, University of North Carolina at Chapel Hill 27599-7450, USA.
authors.forename: J
authors.initials: J
authors.lastname: Perdigão
authors.forename: L
authors.initials: L
authors.lastname: Lopes
authors.forename: P
authors.initials: P
authors.lastname: Lambrechts
authors.forename: J
authors.initials: J
authors.lastname: Leitão
authors.forename: B
authors.initials: B
authors.lastname: Van Meerbeek
authors.forename: G
authors.initials: G
authors.lastname: Vanherle
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000704:Analysis of Variance; D001840:Dental Bonding; D003743:Dental Enamel; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D008855:Microscopy, Electron, Scanning; D009943:Organophosphorus Compounds
chemical_list: C084544:Clearfil Linerbond System; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D009943:Organophosphorus Compounds; C074232:Phenyl-P adhesion promoting monomer