Browsing by Subject "fluoride release"

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    THE EFFECT OF NANO-FILLED RESIN COATING ON FLUORIDE RELEASE IN A NEW CONVENTIONAL GLASS IONOMER CEMENT
    (Office of the Vice Chancellor for Research, 2012-04-13) Al Dehailan, Laila; Eckert, George; Platt, Jeffrey
    The objective of this study was to evaluate fluoride release amounts and patterns from high strength tooth filling material (EQUIA™) which is a con-ventional Glass Ionomer Cement, and investigate whether the application of nano-filled resin-based coating with different thicknesses has any effect on fluoride release from this new material. A total of 120 disc shaped specimens (10 x 2 mm) of EQUIA™ were fabricated according to manufacturer’s in-structions. Samples were subsequently divided into three groups: no resin coating; coated with nano-filled resin-based coat; coated with nano-filled resin-based coat then subjected to abrasion using a mechanical tooth brush-ing machine. Each specimen was soaked individually into a polyethylene container with 20 ml of distilled water and stored at 37ºC. Samples from each group were soaked for four time points; 1 day, 7 days, 14 days and 21 days. Fluoride content was then measured using a fluoride-specific ion elec-trode (Model 9609BNWP, Orion Research, Boston MA, USA). The effects of time and coating on fluoride release were analyzed using two-way analysis of variance (ANOVA), with multiple comparisons performed using the Sidak method at an overall 5% significance level. The distribution of the fluoride release measurements was examined and a natural logarithm transformation of the data was necessary to satisfy the ANOVA assumptions. The time-by-coating interaction was significant (p<0.0001). We can conclude that fluo-ride level significantly increased with time for non-coated and coated then abraded samples only. Application of resin coat significantly reduced fluoride release. Also, subjecting coated samples to tooth brush abrasion increased the fluoride release when compared to coated specimens but was still signifi-cantly less than uncoated samples.
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    Fluoride Release from Fluoride Varnishes under Acidic Conditions
    (2014-09) Lippert, Frank; Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Objective: The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions. Study design: Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80±5 mg fluoride varnish (n=10) and placed into artificial saliva for 30min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30min with the solutions being replaced every 5min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time). Results: The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varnish, Vella) showed the opposite behavior. There was little difference between acidic solutions. Conclusions: Fluoride release from fluoride varnishes varies considerably and also depends on the dissolution medium. Bearing in mind the limitations of laboratory research, the consumption of acidic drinks after fluoride varnish application should be avoided to optimize the benefit/risk ratio.