title: Shear bond strength of composite bonded to Er,Cr:YSGG laser-prepared dentin.
abstract: OBJECTIVE
  The purpose of this in vitro study was to evaluate dentin bond strength to resin composite following high-speed rotary or Er,Cr:YSGG laser preparation using two different adhesive systems.
  
  
  METHODS
  One hundred and forty dentin specimens were prepared from human molars. Seventy specimens were prepared with a high-speed diamond bur and 70 of the specimens were prepared with an Er,Cr:YSGG laser. Each group was subdivided into 7 groups of 10 teeth and etched with either 37% H3PO4, laser etched at two different power levels (1.25 W and 3 W), or not etched. Nano-hybrid composite resin cylinders 4 x 2 mm in size (Tetric EvoCeram, Vivadent) were bonded to the dentin surfaces with the application of an etch-and-rinse adhesive (Exite/Vivadent), or a self-etching adhesive (AdheSe/Vivadent). After storage in distilled water and thermocycling, a shear bond strength test was performed on all specimens and the data were statistically analyzed.
  
  
  RESULTS
  ANOVA detected significant differences between the tested groups (p < 0.001). Duncan's multiple comparison test showed that Excite-applied specimens that were prepared with laser and laser etched (1.25 W or 3 W) had higher mean bond strengths. Both AdheSe- and Excite-applied specimens prepared with the diamond bur and laser etched (1.25 W) showed the lowest mean bond strength values (p < 0.05).
  
  
  CONCLUSIONS
  The results suggest that dentin surfaces prepared with the Er,Cr:YSGG laser and etched with the laser (at either 1.25 or 3 W) may provide comparable or increased composite resin bond strengths, depending on the adhesive used.
authors.affiliation: Hacettepe University, School of Dentistry, Department of Restorative Dentistry, Ankara, Turkey. sgurgan@hacettepe.edu.tr
authors.forename: Sevil
authors.initials: S
authors.lastname: Gurgan
authors.forename: Arlin
authors.initials: A
authors.lastname: Kiremitci
authors.forename: Filiz Yalcin
authors.initials: FY
authors.lastname: Cakir
authors.forename: Jale
authors.initials: J
authors.lastname: Gorucu
authors.forename: Tugba
authors.initials: T
authors.lastname: Alpaslan
authors.forename: Esra
authors.initials: E
authors.lastname: Yazici
authors.forename: Norbert
authors.initials: N
authors.lastname: Gutknecht
mesh_terms: D003188:Composite Resins; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods*; D003804:Dentin / Q000528:radiation effects*; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D009924:Organ Culture Techniques; D033081:Shear Strength / Q000528:radiation effects*
chemical_list: D003188:Composite Resins