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Biomedical subjects

P Gron

Publications and source records attributed to P Gron.

At least 19 recordsLinked to original sources
PubMed1991

CaF2 in enamel biopsies 6 weeks and 18 months after fluoride treatment.

Fluoride concentrations were studied in enamel biopsies from maxillary central incisors 6 weeks and 18 months after fluoride treatment. In the short-term study biopsies were obtained prior to and after treatment with acidic sodium or ammonium fluoride. The findings showed that large amounts of fluoride were deposited in enamel from NH4F treatment (mean concentration 84,723 ppm), indicating substantial CaF2 formation. NaF treatment resulted in mean fluoride concentrations of 7,818 ppm. In the 18-month study, biopsies from 58 placebo-treated teeth were analyzed for total fluoride (mean 1,733 ppm). Twenty-five additional biopsies from placebo-treated and 58 from NH4F-treated teeth were analyzed for KOH-soluble (CaF2) and KOH-nonsoluble (apatitic) fluoride. The mean values for total fluoride were 1,669 and 2,085 ppm in the placebo-treated and in the NH4F-treated groups, respectively. The corresponding mean values for KOH-nonsoluble fluoride were 1,467 and 1,731 ppm and for KOH-soluble fluoride 202 and 354 ppm, respectively. The increase in enamel fluoride after fluoride treatment was only marginally significant. Biopsies from the ammonium fluoride treated group were significantly more likely to have high (30 vs. 8%) and moderate (28 vs. 16%) CaF2 levels and less likely to have low levels than biopsies of placebo-treated teeth (chi-square = 8.0 with 2 d.f.; p = 0.018). It is concluded that very substantial amounts of CaF2 are present in enamel 6 weeks after treatment, and small amounts may persist in the surface enamel for as long as 18 months.

Adolescent↗
PubMed1990

In vivo study of slow-release fluoride resin and enamel uptake.

The purpose of this study was to investigate in vivo enamel fluoride uptake of a slow-release boron trifluoride BIS-GMA resin material. Study subjects were orthodontic patients with at least one pair of permanent bicuspid teeth indicated for extraction. The material was applied to the buccal surface of the test tooth 1 month prior to extraction; the contralateral tooth served as the control tooth. Following extraction, the resin was removed by soaking in acetone for 36 h and polishing with a sodium bicarbonate slurry. Prior scanning electron microscopic studies have shown that this cleaning procedure effectively removes all residual resin. Enamel fluoride analyses were completed for 12 pairs of teeth from 9 subjects. The mean differences in enamel fluoride concentrations between the treated and control teeth were significantly different from zero at the 0.01 level. At each successive depth, the absolute mean amount of fluoride uptake by the test teeth was fairly constant; however, the proportional mean amount or percent increase in fluoride concentration resulting from treatment became greater in the deeper enamel layers. The data suggest that this material has the potential to provide an effective means of introducing substantial amounts of permanently bound fluoride into surface enamel, even into the deeper layers.

Acid Etching, Dental↗
PubMed1987

Enhanced caries inhibition by certain NaF-surfactant combinations in animal models.

The purpose of this animal investigation was to determine whether the cariostatic effect of sodium fluoride can be enhanced by combining it with certain surfactants. The surfactants, Zonyl FSC and Lodyne S-110, were selected because they had been found to accelerate the rate of deposition of firmly-bound fluoride in vitro in enamel during enamel-fluoride interaction. Sixty male hamsters and 60 female rats, 21 days old, were placed on the high-sucrose diet 2000 and inoculated with Streptococcus mutans (strain #6715). Each set of animals was divided into six groups of 10 each. The groups received either distilled water, NaF, NaF with Lodyne S-110, NaF with Zonyl FSC, Lodyne S-110, or Zonyl FSC. The animals were scored for caries at the termination of the study. The caries findings in the hamster and the rat series closely paralleled each other. Animals receiving NaF with Zonyl FSC experienced the least decay (about 90% inhibition compared with about 65% for the NaF-alone group). A statistical evaluation showed significant interaction between Zonyl FSC and NaF. No effect on caries experience was seen from administration of Lodyne S-110.

Animals↗