title: Enamel and dentin bond strengths of a new self-etch adhesive system.
abstract: statement of problem:  Self-etch adhesives typically are mildly acidic and therefore less effective than etch-and-rinse adhesives for bonding to enamel.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the enamel and dentin shear bond strengths of a new two-step self-etch adhesive system, OptiBond XTR (Kerr Corporation, Orange, CA, USA).
  
  
  METHODS
  The labial surfaces of 80 bovine teeth were ground to create flat, 600-grit enamel or dentin surfaces. Composite was bonded to enamel or dentin using the new two-step self-etch system or a three-step etch-and-rinse (OptiBond FL, Kerr), two-step self-etch (Clearfil SE Bond, Kuraray America, Houston, TX, USA), or one-step self-etch adhesive (Xeno IV, Dentsply Caulk, Milford, DE, USA). Following storage in water for 24 hours, shear bond strengths were determined using a universal testing machine. The enamel and dentin data sets were subjected to separate analysis of variance and Tukey's tests. Scanning electron microscopy was used to evaluate the effects of each system on enamel.
  
  
  RESULTS
  Mean shear bond strengths to enamel ranged from 18.1 MPa for Xeno IV to 41.0 MPa for OptiBond FL. On dentin, the means ranged from 33.3 MPa for OptiBond FL to 47.1 MPa for Clearfil SE Bond. OptiBond XTR performed as well as Clearfil SE Bond on dentin and as well as OptiBond FL on enamel. Field emission scanning electron microscope revealed that OptiBond XTR produced an enamel etch pattern that was less defined than that of OptiBond FL (37.5% phosphoric acid) but more defined than that of Clearfil SE Bond or Xeno IV.
  
  
  CONCLUSIONS
  The new two-step self-etch adhesive system formed excellent bonds to enamel and dentin in vitro.
  
  
  CONCLUSIONS
  OptiBond XTR, a new two-step self-etch adhesive system, is a promising material for bonding to enamel as well as to dentin.
authors.affiliation: Department of Preventive and Restorative Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Walter
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Swift
authors.forename: Lee W
authors.initials: LW
authors.lastname: Boushell
authors.forename: Krista
authors.initials: K
authors.lastname: Braswell
mesh_terms: D000269:Adhesives; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003743:Dental Enamel; D003804:Dentin; D033081:Shear Strength
chemical_list: D000269:Adhesives