title: In vitro microleakage of composite restorations prepared by Er:YAG/Er,Cr:YSGG lasers and conventional drills associated with two adhesive systems.
abstract: OBJECTIVE
  The objective of this in vitro study was to compare the degree of microleakage of composite restorations performed by lasers and conventional drills associated with two adhesive systems.
  
  
  METHODS
  Sixty bovine teeth were divided into 6 groups (n = 10). The preparations were performed in groups 1 and 2 with a high-speed drill (HD), in groups 3 and 5 with Er:YAG laser, and in groups 4 and 6 with Er,Cr:YSGG laser. The specimens were restored with resin composite associated with an etch-and-rinse two-step adhesive system (Single Bond 2 [SB]) (groups 1, 3, 4) and a self-etching adhesive (One-Up Bond F [OB]) (groups 2, 5, 6). After storage, the specimens were polished, thermocycled, immersed in 50% silver nitrate tracer solution, and then sectioned longitudinally. The specimens were placed under a stereomicroscope (25X) and digital images were obtained. These were evaluated by three blinded evaluators who assigned a microleakage score (0 to 3). The original data were submitted to Kruskal-Wallis and Mann-Whitney statistical tests.
  
  
  RESULTS
  The occlusal/enamel margins demonstrated no differences in microleakage for all treatments (p > 0.05). The gingival/dentin margins presented similar microleakage in cavities prepared with Er:YAG, Er,Cr:YSGG, and HD using the etch-and-rinse two-step adhesive system (SB) (p > 0.05); otherwise, both Er:YAG and Er,Cr:YSGG lasers demonstrated lower microleakage scores with OB than SB adhesive (p < 0.05).
  
  
  CONCLUSIONS
  The microleakage score at gingival margins is dependent on the interaction of the hard tissue removal tool and the adhesive system used. The self-etching adhesive system had a lower microleakage score at dentin margins for cavities prepared with Er:YAG and Er,Cr:YSGG than the etch-and-rinse two-step adhesive system.
authors: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, Brazil. vmoldes@uol.com.br
authors: Vera Lucia
authors: VL
authors: Moldes
authors: Claudia Ines
authors: CI
authors: Capp
authors: Ricardo Scarparo
authors: RS
authors: Navarro
authors: Adriana Bona
authors: AB
authors: Matos
authors: Michel Nicolau
authors: MN
authors: Youssef
authors: Alessandra
authors: A
authors: Cassoni
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate; D002417:Cattle; D003188:Composite Resins; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods*; D003755:Dental High-Speed Technique; D003763:Dental Leakage; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent; D053844:Lasers, Solid-State; D008689:Methacrylates; D011897:Random Allocation; D019279:Resin Cements
chemical_list: D003188:Composite Resins; D008689:Methacrylates; C446260:One-Up-Bond F; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate