title: Effects of solvent evaporation time on immediate adhesive properties of universal adhesives to dentin.
abstract: OBJECTIVE
  To evaluate the microtensile bond strengths (μTBS) and nanoleakage (NL) of three universal or multi-mode adhesives, applied with increasing solvent evaporation times.
  
  
  METHODS
  One-hundred and forty caries-free extracted third molars were divided into 20 groups for bond strength testing, according to three factors: (1) Adhesive - All-Bond Universal (ABU, Bisco, Inc.), Prime&Bond Elect (PBE, Dentsply), and Scotchbond Universal Adhesive (SBU, 3M ESPE); (2) Bonding strategy - self-etch (SE) or etch-and-rinse (ER); and (3) Adhesive solvent evaporation time - 5s, 15s, and 25s. Two extra groups were prepared with ABU because the respective manufacturer recommends a solvent evaporation time of 10s. After restorations were constructed, specimens were stored in water (37°C/24h). Resin-dentin beams (0.8mm(2)) were tested at 0.5mm/min (μTBS). For NL, forty extracted molars were randomly assigned to each of the 20 groups. Dentin disks were restored, immersed in ammoniacal silver nitrate, sectioned and processed for evaluation under a FESEM in backscattered mode. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. drying time) for each strategy, and Tukey's test (α=0.05). NL data were computed with non-parametric tests (Kruskal-Wallis and Mann-Whitney tests, α=0.05).
  
  
  RESULTS
  Increasing solvent evaporation time from 5s to 25s resulted in statistically higher mean μTBS for all adhesives when used in ER mode. Regarding NL, ER resulted in greater NL than SE for each of the evaporation times regardless of the adhesive used. A solvent evaporation time of 25s resulted in the lowest NL for SBU-ER.
  
  
  CONCLUSIONS
  Residual water and/or solvent may compromise the performance of universal adhesives, which may be improved with extended evaporation times.
authors.affiliation: Department of Restorative Dentistry, State University of Ponta Grossa, Paraná, Brazil.
authors.forename: Issis V
authors.initials: IV
authors.lastname: Luque-Martinez
authors.affiliation: Department of Restorative Sciences, University of Minnesota, Minneapolis, MN, USA. Electronic address: perdi001@umn.edu.
authors.forename: Jorge
authors.initials: J
authors.lastname: Perdigão
authors.affiliation: School of Dentistry, Universidad de Valparaíso, Valparaíso, Chile.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Muñoz
authors.affiliation: Department of Stomatology, University Rey Juan Carlos, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Sezinando
authors.affiliation: Department of Restorative Dentistry, State University of Ponta Grossa, Paraná, Brazil.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
authors.affiliation: Department of Restorative Dentistry, State University of Ponta Grossa, Paraná, Brazil.
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Loguercio
mesh_terms: D003738:Dental Cements; D003763:Dental Leakage; D003804:Dentin; D006801:Humans; D012997:Solvents / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D003738:Dental Cements; D012997:Solvents
keywords: Dentin; Etch-and-rinse; Microtensile bond strength; Nanoleakage; Self-etch; Solvent evaporation; Universal simplified adhesive systems