title: Replacing HEMA with alternative dimethacrylates in dental adhesive systems: evaluation of polymerization kinetics and physicochemical properties.
abstract: OBJECTIVE
  To evaluate the mechanical and physical properties of experimental HEMA-containing and HEMA-free resin adhesives.
  
  
  METHODS
  Experimental HEMA-free adhesives containing alternative dimethacrylates (bis-EMA 10 [B10], bis-EMA 30 [B30], PEG 400 [P400], PEG 1000 [P1000], PEG 400 UDMA [UP400]) were formulated and compared with a HEMA-containing adhesive (control). The adhesives were characterized by rheological analysis, polymerization kinetics (PK), water sorption (WS), and solubility (SL) tests. Flexural strength (FS) and flexural modulus (E) tests were performed under dry or wet conditions (distilled water or 70% ethanol solution). One-way and two-way ANOVA as well as Tukey's test were used to evaluate differences between groups (p < 0.05).
  
  
  RESULTS
  The control group showed the lowest viscosity and was the only one with a degree of conversion lower than 50%. The control and the P1000 adhesive showed the statistically significantly highest WS (p < 0.05). The control and the UP400 adhesive showed the highest FS and E, and the dry-stored specimens showed more improved mechanical strength than did the wet-stored specimens (p < 0.05).
  
  
  CONCLUSIONS
  The physicomechanical properties of some of the HEMA-free adhesives were substantially improved when compared with those of the control, indicating that they could be potential monomers for the development of HEMA-free adhesive systems.
authors.forename: Eliseu Aldrighi
authors.initials: EA
authors.lastname: Münchow
authors.forename: Cesar Henrique
authors.initials: CH
authors.lastname: Zanchi
authors.forename: Fabrício Aulo
authors.initials: FA
authors.lastname: Ogliari
authors.forename: Manuela Gonçalves
authors.initials: MG
authors.lastname: Silva
authors.forename: Isadora Rubin
authors.initials: IR
authors.lastname: de Oliveira
authors.forename: Evandro
authors.initials: E
authors.lastname: Piva
mesh_terms: D000327:Adsorption; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D055119:Elastic Modulus; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D018583:Pliability; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012212:Rheology; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D012997:Solvents; D014867:Water; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D000431:Ethanol; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate