title: Can the hydrophilicity of functional monomers affect chemical interaction?
abstract: The number of carbon atoms and/or ester/polyether groups in spacer chains may influence the interaction of functional monomers with calcium and dentin. The present study assessed the chemical interaction and bond strength of 5 standard-synthesized phosphoric-acid ester functional monomers with different spacer chain characteristics, by atomic absorption spectroscopy (AAS), ATR-FTIR, thin-film x-ray diffraction (TF-XRD), scanning electron microscopy (SEM), and microtensile bond strength (μTBS). The tested functional monomers were 2-MEP (two-carbon spacer chain), 10-MDP (10-carbon), 12-MDDP (12-carbon), MTEP (more hydrophilic polyether spacer chain), and CAP-P (intermediate hydrophilicity ester spacer). The intensity of monomer-calcium salt formation measured by AAS differed in the order of 12-MDDP=10-MDP>CAP-P>MTEP>2-MEP. FTIR and SEM analyses of monomer-treated dentin surfaces showed resistance to rinsing for all monomer-dentin bonds, except with 2-MEP. TF-XRD confirmed the weaker interaction of 2-MEP. Highest µTBS was observed for 12-MDDP and 10-MDP. A shorter spacer chain (2-MEP) of phosphate functional monomers induced formation of unstable monomer-calcium salts, and lower chemical interaction and dentin bond strength. The presence of ester or ether groups within longer spacer carbon chains (CAP-P and MTEP) may affect the hydrophilicity, μTBS, and also the formation of monomer-calcium salts.
authors.affiliation: Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil.
authors.forename: V P
authors.initials: VP
authors.lastname: Feitosa
authors.forename: F A
authors.initials: FA
authors.lastname: Ogliari
authors.forename: B
authors.initials: B
authors.lastname: Van Meerbeek
authors.forename: T F
authors.initials: TF
authors.lastname: Watson
authors.forename: K
authors.initials: K
authors.lastname: Yoshihara
authors.forename: A O
authors.initials: AO
authors.lastname: Ogliari
authors.forename: M A
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: A B
authors.initials: AB
authors.lastname: Correr
authors.forename: G
authors.initials: G
authors.lastname: Cama
authors.forename: S
authors.initials: S
authors.lastname: Sauro
mesh_terms: D002118:Calcium / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure; D004852:Epoxy Compounds; D004853:Epoxy Resins / Q000737:chemistry; D005233:Fatty Alcohols / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010755:Organophosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013054:Spectrophotometry, Atomic; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D003188:Composite Resins; D004852:Epoxy Compounds; D004853:Epoxy Resins; D005233:Fatty Alcohols; D008689:Methacrylates; D010755:Organophosphates; D011109:Polymethacrylic Acids; D019279:Resin Cements; C098757:1,12-dodecanediol dimethacrylate; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C071507:2-methyl-1,2-epoxypropane; C118975:1,10-decanediol; D002244:Carbon; C069749:methacryloyloxydecyl dihydrogen phosphate; D002118:Calcium
keywords: adhesives; bonding; dentin; electron microscopy; methacrylates; restorative dentistry