title: Experimental self-etching HEMA-free adhesive systems: cytotoxicity and degree of conversion.
abstract: The aim of this study was to evaluate the effect of replacing 2-hydroxyethyl methacrylate (HEMA) by methacrylate surfactant monomers on the cytotoxicity and degree of conversion of two-step self-etching dentin adhesive systems. Five HEMA-free adhesive systems were tested: Bis-EMA 10, Bis-EMA 30, PEG400, PEG400UDMA, PEG1000, and a HEMA group was used as positive control. The cytotoxicity of the experimental primers, with different monomer concentrations (2 or 20 wt%), and bond resins, containing 25 wt% surfactant, was assessed using murine fibroblast cell line 3T3 and the tetrazolium assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)). The degree of conversion of the bond resins was analyzed using Fourier transform infrared spectroscopy. The data were submitted to statistical analysis using level of significance set at P < 0.05. The PEG 1000 group obtained higher cell viability in comparison with HEMA in the 2 % primer. The cell survival rate using 20 % primer showed that PEG1000 and BIS-EMA 10 were less cytotoxic than HEMA. With regard to the eluate from bond resin, the data showed that the groups BIS-EMA 10, BIS-EMA 30 and PEG400UDMA were less cytotoxic than HEMA. No statistically significant difference was found among degrees of conversion of the experimental groups and HEMA. PEG 1000, BIS-EMA 10 and 30 monomers showed the biological potential for use in new adhesive system formulations since they showed lower cytotoxicity and similar degree of conversion when compared with the HEMA-containing group.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, Federal University of Pelotas, Rua Gonçalves Chaves 457 sala 504, Centro, Pelotas, RS, 96015560, Brazil.
authors.forename: Marília Oliveira
authors.initials: MO
authors.lastname: Barbosa
authors.forename: Rodrigo Varella
authors.initials: RV
authors.lastname: de Carvalho
authors.forename: Flávio Fernando
authors.initials: FF
authors.lastname: Demarco
authors.forename: Fabrício Aulo
authors.initials: FA
authors.lastname: Ogliari
authors.forename: Cesar Henrique
authors.initials: CH
authors.lastname: Zanchi
authors.forename: Evandro
authors.initials: E
authors.lastname: Piva
authors.forename: Adriana Fernandes
authors.initials: AF
authors.lastname: da Silva
mesh_terms: D016475:3T3 Cells; D000134:Acid Etching, Dental / Q000379:methods; D000269:Adhesives; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002470:Cell Survival; D001840:Dental Bonding; D003804:Dentin / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D051379:Mice; D008970:Molecular Weight; D019279:Resin Cements / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C005044:hydroxyethyl methacrylate