title: Microtensile bond strength analysis of different adhesive systems and dentin prepared with high-speed and Er:YAG laser: a comparative study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the bond strength of two adhesive systems (Single Bond and Clearfil SE Bond) subjected or not to a thermocycling procedure and applied to cavities prepared either with high-speed diamond bur or Er:YAG laser.
  
  
  BACKGROUND
  One of the possible applications of dental lasers includes increasing the quality of bond strength.
  
  
  METHODS
  This in vitro study was carried out using a microtensile test on 16 bovine teeth, divided into eight groups. Cavities were prepared on superficial dentin of the medium portion of the buccal surface. After application of adhesive systems, composite restorations were performed at 5-mm height. After 24 h, four groups of teeth were immersed in water, and the other four were thermocycled. Bonded specimens were sectioned into serial 1x1-mm beams, which were subjected to a microtensile test. Final values of bond strength were measured, expressed in MPa, and statistically analyzed.
  
  
  RESULTS
  Results were as follows: G1 (26.281 +/- 5.454 MPa); G2 (10.965 +/- 3.714 MPa); G3 (18.549 +/- 6.113 MPa); G4 (14.295 +/- 3.806 MPa); G5 (18.225 +/- 5.701 MPa); G6 (5.588 +/- 2.211 MPa); G7 (18.256 +/- 3.819 MPa); and G8 (15.423 +/- 4.714 MPa).
  
  
  CONCLUSIONS
  Self-etching adhesive system (SE) produced more stable bond strength results than the system that indicates total etching (SB). For dentin prepared at high speed, the total etching adhesive system was more indicated, whereas Er:YAG laser-preparation dentin was not influenced by the adhesive system. The thermocycling procedure could negatively affect microtensile bond strength of both adhesive systems, being more deleterious to SB than to SE.
authors.affiliation: State University of Feira de Santana, Health Department, Bahia, Brazil. denise@uefs.br
authors.forename: Denise Cerqueira
authors.initials: DC
authors.lastname: Oliveira
authors.forename: Lussara Azevedo
authors.initials: LA
authors.lastname: Manhães
authors.forename: Márcia Martins
authors.initials: MM
authors.lastname: Marques
authors.forename: Adriana Bona
authors.initials: AB
authors.lastname: Matos
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects*; D002417:Cattle; D001840:Dental Bonding / Q000295:instrumentation / Q000379:methods; D003731:Dental Caries / Q000628:therapy; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods; D003793:Dental Restoration, Permanent; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects*; D006358:Hot Temperature; D066298:In Vitro Techniques; D007834:Lasers; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D013718:Tensile Strength / Q000528:radiation effects; D013816:Thermodynamics
chemical_list: C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate