title: Longitudinal Evaluation of Bond Strength to Enamel of Dental Adhesive Systems Associated with Nd:YAG Laser.
abstract: OBJECTIVE
  This study evaluated the durability of bond strength to enamel using total-etch (Single Bond/SB) and self-etch (Clearfil SE Bond/CSEB) adhesives associated with neodymium:yttrium-aluminu-garnet (Nd:YAG) laser irradiation through the uncured adhesives.
  
  
  METHODS
  Bovine incisors were worn to expose an area of enamel and were divided into four groups: group 1 (control) SB + polymerization; group 2 (control) CSEB + polymerization; group 3 (laser) - SB + Nd:YAG laser (174.16 J/cm(2)) + polymerization; and group 4 (laser) CSEB + Nd:YAG (174.16 J/cm(2)) + polymerization. Blocks of composite were fabricated and stored for 24 hours or 12 months, sectioned into beams, and submitted to microtensile tests. Results were analyzed by three-way analysis of variance (ANOVA) (adhesive, technique, and storage time) and Tukey tests.
  
  
  RESULTS
  ANOVA revealed significant differences for adhesive × technique and technique × storage time (p<0.05). The mean values (MPa) for interaction adhesive × technique (standard deviation) were as follows: SB/control = 35.78 (6.04)a; SB/laser = 26.40 (7.25)b, CSEB/control = 26.32 (5.71)b, CSEB/laser = 23.90 (7.49)b. For interaction technique × storage time the mean values were as follows: control/24 hours = 32.58 (6.49)a; control/12 months = 29.52 (8.38)a; laser/24 hours = 29.37 (5.71)a; laser/12 months = 20.92 (6.5)b. Groups with the same letters showed no statistically significant differences.
  
  
  CONCLUSIONS
  Scanning electron microscope analysis showed evident areas of micromorphological alterations in lased samples after 12 months of water storage. Nd:YAG laser irradiation of enamel through unpolymerized total-etch adhesive significantly reduced bond strength compared with the control. Bond strength decreased when enamel samples irradiated with Nd:YAG laser through unpolymerized adhesives were stored in water for 12 months.
authors.forename: D C
authors.initials: DC
authors.lastname: Barcellos
authors.forename: G R
authors.initials: GR
authors.lastname: Batista
authors.forename: C R
authors.initials: CR
authors.lastname: Pucci
authors.forename: E S
authors.initials: ES
authors.lastname: Persici
authors.forename: A B
authors.initials: AB
authors.lastname: Borges
authors.forename: C R G
authors.initials: CR
authors.lastname: Torres
authors.forename: B M
authors.initials: BM
authors.lastname: Fonseca
authors.forename: S E P
authors.initials: SE
authors.lastname: Gonçalves
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000627:therapeutic use; D002417:Cattle; D001840:Dental Bonding / Q000379:methods* / Q000592:standards; D003743:Dental Enamel / Q000378:metabolism*; D003799:Dental Stress Analysis; D053685:Laser Therapy; D055115:Light-Curing of Dental Adhesives / Q000379:methods* / Q000592:standards; D008137:Longitudinal Studies; D019279:Resin Cements / Q000627:therapeutic use; D013718:Tensile Strength
chemical_list: C438313:Clearfil SE Bond; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate