title: Long-term effects of four extraction media on the fluoride release from four polyacid-modified composite resins (compomers) and one resin-modified glass-ionomer cement.
abstract: It was the aim of the present experiments to evaluate the fluoride leaching of four compomers and one resin-modified glass-ionomer cement (gic) into aqueous media over a 1-year period. Various extraction/equilibrium solutions were applied to simulate important intraoral parameters. Specimens of Dyract, Compoglass F, F2000, one experimental compomer, and the resin-modified gic Fuji II LC were stored for 366 days in distilled water (I), acidic medium (pH 4.2) (II), neutral medium (pH 7.0) (III), or solution III supplemented with 1.6 u/mL porcine liver esterase (IV). Equilibrium media were changed and fluoride concentration was measured every 48 h (first 30 d), thereafter each week (twice), then every 14 d (three times), and finally every 28 d up to a total period of 1 year. Data were statistically analyzed for significant differences by means of Scheffe' tests (p < 0.05). The gic and the compomers leached significantly more fluoride into the acidic solution in the initial phase compared to the other media (p < 0.05). Cumulative fluoride release from all materials (except experimental compomer) was elevated because of esterase activity (p <0.05). Measurable but low quantities of fluoride were segregated into all media during the 1-year period. But no significantly different long-term fluoride release into the various media from the investigated materials was found. The data indicate that plaque-associated organic acids or salivary hydrolases may increase initial fluoride release from resin-modified gics or compomers in the oral cavity. Because long-term fluoride release from all materials decreased to low concentrations within a 30-day period, their caries preventive effect remains questionable.
authors.affiliation: Department of Conservative Dentistry and Periodontology, Medical University, Hannover, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Behrend
authors.forename: W
authors.initials: W
authors.lastname: Geurtsen
mesh_terms: D000818:Animals; D020770:Compomers / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000517:prevention & control; D004950:Esterases / Q000494:pharmacology; D005459:Fluorides / Q000032:analysis*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000201:enzymology; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000494:pharmacology*; D013552:Swine; D013997:Time Factors; D014867:Water / Q000494:pharmacology
chemical_list: C105428:Compoglass; D020770:Compomers; D003188:Composite Resins; C088486:Dyract; C118368:F2000 cement; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D008689:Methacrylates; D012117:Resins, Synthetic; D017640:Silicates; D012997:Solvents; D014867:Water; D004950:Esterases; D005459:Fluorides