title: Bond Strength of Experimental Low-viscosity Resin Materials to Early Enamel Caries Lesions: Effect of Diluent/Solvent Addition.
abstract: OBJECTIVE
  To evaluate the effect of different concentrations of monomers and solvents/diluents on the microtensile bond strength (μTBS) bond strength of experimental low-viscosity resins (infiltrants) to enamel caries-like lesions (ECLL).
  
  
  METHODS
  Flat enamel blocks obtained from sound human third molars were submitted to ECLL formation and randomly distributed into 9 groups (n = 10): G1: TEG-DMA 100%; G2: TEG-DMA 80%, ethanol 20%; G3; TEG-DMA 80%, HEMA 20%; G4: TEG-DMA 75%, UDMA 25%; G5: TEG-DMA 60%, UDMA 20%, ethanol 20%; G6: TEG-DMA 60%, UDMA 20%, HEMA 20%; G7: TEG-DMA 75%, bis-EMA 25%; G8: TEG-DMA 60%, bis-EMA 20%, ethanol 20%; G9: TEG-DMA 60%, bis-EMA 20%, HEMA 20%. After etching with 37% phosphoric acid for 60 s, experimental infiltrants were actively applied and photocured for 60 s, then stored in 100% humidity (24 h, 37°C). Hourglass-shaped specimens were obtained and the μTBS test performed (MPa). The fracture patterns were assessed by SEM. Data were submitted to two way-ANOVA and Tukey's tests (α = 0.05).
  
  
  RESULTS
  The highest μTBS value was observed for G4 (TEG-DMA/UDMA, 19.18 MPa) and the lowest for G5 (TEG-DMA/UDMA/ethanol, 9.00 MPa). A significant decrease in μTBS was observed for all groups containing ethanol (G2, G5, and G8). The addition of HEMA did not affect μTBS values. Most groups showed a high frequency of mixed failure between infiltrant and enamel.
  
  
  CONCLUSIONS
  The addition of bis-EMA or UDMA to TEG-DMA-based infiltrants did not improve bond strength to carious enamel. The ethanol addition negatively affected the bonding strength of infiltrants to enamel caries-like lesions, regardless of the resin matrix composition of the infiltrant.
authors.forename: Tatiany Gabrielle Freire
authors.initials: TG
authors.lastname: Araújo
authors.forename: Ravana Angelini
authors.initials: RA
authors.lastname: Sfalcin
authors.forename: Giovana Spagnolo Albamonte
authors.initials: GS
authors.lastname: de Araújo
authors.forename: Roberta Caroline Brusch
authors.initials: RC
authors.lastname: Alonso
authors.forename: Regina Maria
authors.initials: RM
authors.lastname: Puppin-Rontani
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003743:Dental Enamel / Q000648:ultrastructure*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D012997:Solvents; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D000431:Ethanol; D011092:Polyethylene Glycols; C005044:hydroxyethyl methacrylate; C030242:phosphoric acid