title: Influence of Er:YAG laser on cavity preparation and surface treatment in microleakage of composite resin restorations.
abstract: OBJECTIVE
  The purpose of this study was to assess microleakage on class V cavities prepared by Er:YAG laser with varying surface treatment.
  
  
  BACKGROUND
  There has been little reported research on microleakage at cavities prepared and treated with Er:YAG laser.
  
  
  METHODS
  Fifty preparations using Er:YAG laser or a highspeed handpiece were developed. The surface treatment was performed as follows: Er:YAG laser (group 1); 35% phosphoric acid (group 2); laser + acid (group 3); finishing with low-speed + laser + acid (group 4); conventional preparation developed with a high-speed handpiece + acid (group 5--control). The samples were restored with Single Bond/Z250, thermocycled, isolated, and immersed in a 50% AgNO(3) solution. The restorations were sectioned, and the microleakage was measured in milimeters using a specific computer software. Data were analyzed employing ANOVAand Tukey test.
  
  
  RESULTS
  Statistical analysis showed that group 5 (G5) obtained the lowest results of microleakage (22.05%), and it was statistically similar (p > 0.05) to G1 (37.7%) and different (p < 0.05) from the other groups (G2 = 50.4%; G3 = 43%; G4 = 44.2%). The occlusal margins (22.62%) demonstrated less microleakage (p < 0.05) than the cervical margins (56.32%).
  
  
  CONCLUSIONS
  The use of Er:YAG laser for cavity preparation and surface treatment negatively influenced the marginal sealing of composite resin restorations.
authors.affiliation: Department of Operative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo (USP), Brazil.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Chinelatti
authors.forename: Renata P
authors.initials: RP
authors.lastname: Ramos
authors.forename: Daniela T
authors.initials: DT
authors.lastname: Chimello
authors.forename: Silmara A M
authors.initials: SA
authors.lastname: Corona
authors.forename: Jesus D
authors.initials: JD
authors.lastname: Pécora
authors.forename: Regina G Palma
authors.initials: RG
authors.lastname: Dibb
mesh_terms: D003188:Composite Resins; D003737:Dental Cavity Preparation / Q000379:methods*; D003763:Dental Leakage / Q000517:prevention & control; D006801:Humans; D066298:In Vitro Techniques; D007834:Lasers
chemical_list: D003188:Composite Resins