title: Effect of hydrostatic pressure on the diffusion of monomers through dentin in vitro.
abstract: In previous work, the diffusion of monomers from composite and bonding resins through dentin was demonstrated in vitro. The monomers triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) were identified in samples from the pulp space. In the current study, we examined the effects of two levels of positive hydrostatic pressure on the passage of resin monomers through dentin in vitro from a composite-resin/bonding-resin combination to test the hypothesis that monomer diffusion is prevented by such pressure. An occlusal cavity prepared in the tooth crown was restored with the resins. Distilled water samples from the pulpal space were removed over time and analyzed for monomer content by high-performance liquid chromatography and mass spectrometry. Positive pulpal pressure reduced but did not prevent pulpward movement of diluent monomers that leach from bonding agents and from resin composites through dentin in vitro. The degree of reduction of diffusion was greater with TEGDMA than with the lower-molecular-weight monomer HEMA.
authors.affiliation: Department of Restorative Dentistry, University of California, San Francisco 94143-0758.
authors.forename: T M
authors.initials: TM
authors.lastname: Gerzina
authors.forename: W R
authors.initials: WR
authors.lastname: Hume
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003188:Composite Resins / Q000493:pharmacokinetics; D003782:Dental Pulp / Q000502:physiology*; D003804:Dentin / Q000378:metabolism; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000493:pharmacokinetics; D004058:Diffusion; D006801:Humans; D006874:Hydrostatic Pressure; D066298:In Vitro Techniques; D008689:Methacrylates / Q000493:pharmacokinetics*; D011092:Polyethylene Glycols / Q000493:pharmacokinetics*; D011109:Polymethacrylic Acids / Q000493:pharmacokinetics*; D011671:Pulpitis / Q000503:physiopathology; D019279:Resin Cements; D012822:Silicon Dioxide / Q000493:pharmacokinetics; D015040:Zirconium / Q000493:pharmacokinetics
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011109:Polymethacrylic Acids; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C005044:hydroxyethyl methacrylate; D012822:Silicon Dioxide; D015040:Zirconium