title: Effect of diphenyliodonium hexafluorphosphate on resin cements containing different concentrations of ethyl 4-(dimethylamino)benzoate and 2-(dimethylamino)ethyl methacrylate as co-initiators.
abstract: The present study evaluated the influence of diphenyliodonium hexafluorphosphate (DPI) combined with two different amines [ethyl 4-(dimethylamino)benzoate (EDAB) and 2-(dimethylamino)ethyl methacrylate (DMAEMA)] on the properties of model resin cements.
  
  
  
  A comonomer base containing a 1:1 mass ratio of 2.2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) was obtained, after which 1mol% of camphorquinone and 0.1mol% of hydroxyl butyl toluene were added to the comonomer blend. Concentrations of co-initiators varied at 0, 0.5 or 1mol% for DPI and in 1 or 2mol% for amines (DMAEMA or EDAB). Silanated Ba-Al-Si glass (60wt%) was added as filler. The combination of each amine and DPI concentration resulted in 12 formulations, which had the following properties analyzed: degree of conversion (DC), water sorption (Wsp) and solubility (Wsl), flexural strength (FS) and flexural modulus (Ef). Data for DC, FS and Ef were analyzed by two-way ANOVA and Tukey's test (α=0.05) and Wsp and Wsl by Kruskal-Wallis and Dunn tests (α=0.05).
  
  
  
  EDAB promoted a higher DC than did DMAEMA; however, DPI increased DC for all materials with DMAEMA. The physical properties of resin formulations containing EDAB were significantly better than those of groups with DMAEMA; however, DPI had a positive influence on the chemical and physical properties of the model resin cement containing DMAEMA, especially with higher concentrations of amine.
  
  
  
  EDAB proved to be more reactive than DMAEMA, being less influenced by DPI. Resins containing a 1:2 CQ/amine ratio had better properties than those with 1:1.
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, Zip Code 13414-903, Brazil. Electronic address: kamila_guedes@hotmail.com.
authors.forename: Kamila Menezes Guedes de
authors.initials: KM
authors.lastname: Andrade
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, Zip Code 13414-903, Brazil. Electronic address: alanrmp@yahoo.com.br.
authors.forename: Alan Rodrigo
authors.initials: AR
authors.lastname: Palialol
authors.affiliation: Department of Restorative Dentistry, Federal University of Rio Grande do Sul-UFRGS, Rua Ramiro Barcelos, 2492- Santa Cecília, Zip-Code 90035003, Porto Alegre, RS, Brazil. Electronic address: aclancellotti@hotmail.com.
authors.forename: Ailla C
authors.initials: AC
authors.lastname: Lancellotti
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, Zip Code 13414-903, Brazil. Electronic address: baguiar@unicamp.br.
authors.forename: Flávio Henrique Baggio
authors.initials: FH
authors.lastname: Aguiar
authors.affiliation: School of Dentistry and Photon Science Institute, JR Moore Building, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom. Electronic address: david.watts@manchester.ac.uk.
authors.forename: David C
authors.initials: DC
authors.lastname: Watts
authors.affiliation: Dental School, University of Uberaba, Campus Centro - Av. Guilherme Ferreira, 217-Centro, Zip Code: 38010-200, Uberaba, MG, Brazil. Electronic address: goncalves1976@yahoo.com.br.
authors.forename: Luciano Souza
authors.initials: LS
authors.lastname: Gonçalves
authors.affiliation: Dental Research Division, Paulista University, Rua Doutor Bacelar, 1212, Zip Code: 04026-002, Sao Paulo, Brazil. Electronic address: lima.adf@gmail.com.
authors.forename: Adriano Fonseca
authors.initials: AF
authors.lastname: Lima
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, Zip Code 13414-903, Brazil. Electronic address: gimarchi@fop.unicamp.br.
authors.forename: Giselle Maria
authors.initials: GM
authors.lastname: Marchi
mesh_terms: D001565:Benzoates; D001713:Biphenyl Compounds; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D009861:Onium Compounds; D019279:Resin Cements
chemical_list: D001565:Benzoates; D001713:Biphenyl Compounds; D008689:Methacrylates; D009861:Onium Compounds; D019279:Resin Cements; C031291:diphenyliodonium; C049840:2-(dimethylamino)ethyl methacrylate
keywords: Degree of conversion; Flexural modulus; Mechanical properties