title: Nd:YAG laser influence on microtensile bond strength of different adhesive systems for human dentin.
abstract: OBJECTIVE
  The purpose of this study was to investigate the influence of Nd:YAG on microtensile bond strength (microTBS) of different adhesive systems for human dentin.
  
  
  BACKGROUND
  Lasers have been widely used in dentistry. New adhesive systems with different chemical compositions are introduced every year, and it is important to investigate the bonding of new adhesive systems to dentin irradiated with laser.
  
  
  METHODS
  The occlusal surfaces of third molars were removed to obtain flat dentin surfaces. The teeth were randomly divided into six groups. Each adhesive system was applied, according to manufacturers' instructions, to surface dentine with and without Nd:YAG laser irradiation (0.9 W, 15 Hz, 60 mJ per pulse). A block of composite resin was built over the adhesive layer. The specimens were sectioned to obtain 0.70 x 0.70 mm of transversal section. Twenty test specimens were selected for each group, and were then submitted to microTBS on a universal testing machine.
  
  
  RESULTS
  According to Student's t-test, for Single Bond, there was no statistically significant difference without (49.32 MPa) and with (47.34 MPa) laser application (p = 0.60). For the Tyrian SPE/One Step Plus, microTBS value with laser (27.09 MPa) was statistically higher than without laser (19.13 MPa), as well as for Adper Prompt L-Pop (22.85 and 13.78 Mpa; p < or = 0.01).
  
  
  CONCLUSIONS
  The application of Nd:YAG laser to dentin provided an increase in the bond strength values for the Tyrian SPE/One Step Plus and Adper Prompt L-Pop adhesive systems, but did not influence the bond strength values of the Single Bond adhesive system.
authors.affiliation: Department of Dentistry, Pontificial Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Juliana Nunes
authors.initials: JN
authors.lastname: Rolla
authors.forename: Eduardo Gonçalves
authors.initials: EG
authors.lastname: Mota
authors.forename: Hugo Mitsuo Silva
authors.initials: HM
authors.lastname: Oshima
authors.forename: Luiz Henrique Burnett
authors.initials: LH
authors.lastname: Júnior
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Spohr
mesh_terms: D001840:Dental Bonding / Q000379:methods; D003804:Dentin / Q000528:radiation effects*; D017220:Dentin-Bonding Agents / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D013718:Tensile Strength
chemical_list: D017220:Dentin-Bonding Agents