title: Bond strength of self-etch adhesives to pre-etched enamel.
abstract: OBJECTIVE
  Bond strengths of composite resin to enamel using four self-etch adhesive (SEA) systems were compared with the bond strength of an etch-and-rinse adhesive (ERA) system, for both polished enamel and enamel pre-etched with phosphoric acid. The objective was to determine if the pre-etching would increase the bond strengths of the SEA systems to match the ERA system.
  
  
  METHODS
  Ten specimens were used for each adhesive to determine 24-h resin composite to enamel shear bond strengths (SBS) to polished (4000 grit) human enamel and this was repeated for the SEA systems for enamel that was pre-etched with phosphoric acid for 15s. SEM analysis was made to assess the degree of etching and resin penetration into enamel for each of the adhesive systems. Data were analyzed by a two factor ANOVA with a Tukey HSD post hoc test.
  
  
  RESULTS
  The SBS to polished enamel for all four SEA systems were statistically significantly lower (p<0.05) than the ERA control, but with pre-etched enamel there were no statistically significant differences (p>0.05) between any of the adhesive systems. All four of the SEA systems demonstrated statistically significant increases in bond strength between bonding to polished and pre-etched enamel, ranging from 27% to 86%. The results of SEM analysis showed no differences in the resin penetration patterns of any of the adhesives for enamel that was etched with phosphoric acid.
  
  
  CONCLUSIONS
  Pre-etching enamel may enhance the bond strength of SEA systems to values comparable with those found with ERA adhesive systems, which may improve their overall performance in clinical use.
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE 68178, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Erickson
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Barkmeier
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Kimmes
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003764:Dental Materials / Q000737:chemistry; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry* / Q000145:classification; D033081:Shear Strength; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors; D015040:Zirconium / Q000737:chemistry
chemical_list: C505694:Clearfil S3 Bond; C438313:Clearfil SE Bond; D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; C408584:Prompt L-Pop; D019279:Resin Cements; C511238:Single Bond Plus; C417842:Xeno compomer; C083568:Z100 composite resin; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D015040:Zirconium; C030242:phosphoric acid