title: Tetrahydrofuran as solvent in dental adhesives: cytotoxicity and dentin bond stability.
abstract: OBJECTIVE
  The aim of this study was to investigate the cytotoxicity and 1-year dentin bond stability of solvated etch-and-rinse dental adhesives based on tetrahydrofuran (THF), acetone, or ethanol, containing water or not.
  
  
  METHODS
  Seven primers were prepared using the following solvents: THF, acetone, ethanol, water, THF/water, acetone/water, and ethanol/water. Bovine dentin was used, and specimens for microtensile bond strength (μTBS) test were prepared. Specimens were tested after storage in distilled water for 24 h or 1 year. Cytotoxicity of the solvents was evaluated in 3T3/NIH mouse fibroblasts using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after exposure for 24 h.
  
  
  RESULTS
  No significant differences were detected among solvents after storage for 24 h, except for the water-based group, which showed the lowest μTBS values. After storage for 1 year, the THF-based adhesive system resulted in more stable bonds. Yet, THF showed an intermediate cytotoxicity when compared with the other solvents, being less toxic than phosphate monomer and similar to 2-hydroxyethyl methacrylate.
  
  
  CONCLUSIONS
  THF seems to be a suitable solvent for adhesive systems.
  
  
  CONCLUSIONS
  THF is a promising solvent that can be used to improve dentin bond stability.
authors.affiliation: Operative Dentistry Department, School of Dentistry, Federal University of Pelotas, Rua Gonçalves Chaves, 457, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Silvia Terra
authors.initials: ST
authors.lastname: Fontes
authors.forename: María Raquel
authors.initials: MR
authors.lastname: Fernández
authors.forename: Fabrício Aulo
authors.initials: FA
authors.lastname: Ogliari
authors.forename: Rodrigo Varella
authors.initials: RV
authors.lastname: de Carvalho
authors.forename: Rafael Ratto
authors.initials: RR
authors.lastname: de Moraes
authors.forename: Márcia Bueno
authors.initials: MB
authors.lastname: Pinto
authors.forename: Evandro
authors.initials: E
authors.lastname: Piva
mesh_terms: D000096:Acetone / Q000633:toxicity; D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D003124:Colorimetry / Q000379:methods; D004396:Coloring Agents; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000633:toxicity*; D000431:Ethanol / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects; D005663:Furans / Q000633:toxicity*; D008422:Materials Testing; D008689:Methacrylates / Q000633:toxicity; D051379:Mice; D041681:NIH 3T3 Cells; D011897:Random Allocation; D012997:Solvents / Q000633:toxicity*; D013314:Stress, Mechanical; D013718:Tensile Strength; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D017220:Dentin-Bonding Agents; D005663:Furans; D008689:Methacrylates; D012997:Solvents; D013778:Tetrazolium Salts; D013844:Thiazoles; D014867:Water; D000096:Acetone; D000431:Ethanol; C018674:tetrahydrofuran; C005044:hydroxyethyl methacrylate; C022616:thiazolyl blue