Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLUORIDATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

Post-treatment effect of fluoride varnishes in children with a high prevalence of dental caries in a community with fluoridated water.

Children with a high prevalence of dental caries living in a community with fluoridated water had received semi-annual half-mouth applications of one of two fluoride varnishes for three years. Two years after the applications were discontinued, we studied the post-treatment effect of the varnishes. The absolute reduction in caries found during the treatment was retained, but the cariostatic effect did not continue after treatment. This finding suggests that fluoride varnish applications should not be discontinued after three years.

Adolescent↗

Enamel fluoride retention after DCPD and APF application and prolonged exposure to fluoride in vitro.

The effect of a topical fluoride regimen consisting of a four-minute pre-treatment with a saturated dicalcium phosphate dihydrate (DCPD) solution followed by a four-minute application of APF was compared with that of a four-minute application of APF alone with respect to the deposition of fluoride in enamel in an apatitic form in vitro. Following the topical applications, specimens were washed in either (1) an inorganic wash solution for 24 hrs or (2) an inorganic wash solution with 1 ppm F added for 28 days; specimens were then subjected to KOH extraction for 24 hrs. Fluoride-by-depth profiles revealed that the DCPD/APF treatment resulted in a significant increase in the apatitic F concentration of enamel to a depth of 20 microns, while APF application alone did not. All groups exposed to the 1 ppm F wash acquired significant amounts of apatitic F, with the differences between groups remaining relatively constant.

Acidulated Phosphate Fluoride↗

Effect of toothbrushing with 0.4% stannous fluoride and 0.22% sodium fluoride gel on gingivitis for 18 months.

This study determined the effect of brushing with 0.4% stannous fluoride (SnF2) or 0.22% sodium fluoride (NaF) on clinical and microbial parameters associated with gingivitis. The study included three groups of 281 subjects. Subjects in all three groups were instructed to brush twice daily with an ADA-accepted fluoride dentifrice, rinse their mouths with water, and subsequently brush with 0.4% SnF2, 0.22% NaF, or a fluoridefree placebo gel. More stain was detected in the SnF2 group than in the other two groups at all periods except at baseline. However, no differences were observed in gingivitis, bleeding, or mean proportions of microbial forms in the SnF2 or NaF groups when compared with the placebo group at 18 months. Results indicate that 0.4% SnF2, or 0.22% NaF is no more effective than a placebo in reducing gingivitis.

Adult↗

Applicability of acid-etching techniques for fluoride determination on enamel after topical fluoride treatment.

A common technique for fluoride gradient determination of enamel is based on acid-etching of thin enamel layers. The dissolution of CaF2-like material in two different acid-etching solutions was compared with the dissolution of pure CaF2. The results showed that the CaF2-like material deposited on enamel after a topical treatment with 2% NaF dissolved almost completely in the 1 M HClO4 and 1.6 N HCl/70% glycerol solutions. The dissolution of pure CaF2 in the same solutions was low. Even after 30 min, less than 9% of the CaF2 had dissolved. It was concluded that acid-etching techniques for fluoride determination could be used on enamel treated topically with fluoride. The study also indicated that CaF2-like material may have chemical properties different from pure CaF2.

Acid Etching, Dental↗

Mixed uranium chloride fluorides UF6-nCln and methoxyuranium fluorides UF6-n(OCH3)n: a theoretical study of equilibrium geometries, vibrational frequencies, and the role of the f orbitals.

The title compounds, the uranium (VI) fluoride chlorides (UF6-nCln, n = 0-6) and methoxyuranium (VI) fluorides [UF6-n(OCH3)n, n = 0-5], have been studied using relativistic density functional theory. Applying the B3LYP hybrid functional and an effective core potential on uranium, equilibrium geometries have been calculated for these molecules. In addition, harmonic vibrational frequencies have been computed for the chloride fluorides. Calculated frequencies have been compared to experiment where possible. All experimentally observed bands have been assigned, based on these calculations. The average deviation between theoretical and experimental frequencies is 15.6 cm-1 for 23 experimental modes. Theory always underestimates the experimental frequencies. This can be explained by the calculated bond lengths that are somewhat too long. The electronic structure of the uranium (VI) chloride fluorides has been investigated using scalar relativistic calculations and the PW91 functional. Periodic trends in the role and bonding contribution of the uranium 5f orbitals are discussed.

Journal Article↗

Stable dialkyl ether/poly(hydrogen fluoride) complexes: dimethyl ether/poly(hydrogen fluoride), a new, convenient, and effective fluorinating agent.

The preparation, (1)H, (13)C, and (19)F NMR structural characterization as well as with DFT-based theoretical calculations of stable dialkyl ether/poly(hydrogen fluoride) complexes are reported. Dimethyl ether/poly(hydrogen fluoride) (DMEPHF), are stable complexes of particular interest and use. The DFT calculations, that are in agreement with NMR data, suggest a cyclic poly(hydrogen fluoride) bridged structure for DMEPHF. The complex, DME-5 HF was found to be a convenient and effective new fluorinating agent with the ease of workup and applied to several fluorination reactions, such as the hydrofluorination and bromofluorination of alkenes, and fluorination of alcohols giving good to excellent yield with high selectivity. Homologous dialkyl ether/poly(hydrogen fluoride) (R(2)O/[HF](n,), R = Et, nPr) systems are also stable and suitable for fluorination reactions.

Journal Article↗

Does sodium fluoride in bone cement affect implant fixation. Part II: evaluation of the effect of sodium fluoride additions to acrylic bone cement and the fixation of titanium implants in ovariectomized rabbits.

Bone integration of threaded implants made of cured polymethylmethacrylate containing sodium fluoride or commercially pure (c.p.) titanium were studied in normal and estrogen deficient New Zealand white rabbits. Nine had been ovariectomized through laparoscopy and nine served as controls. Four weeks after the ovariectomy two threaded implants made of cured bone cement with or without sodium fluoride addition were inserted in each tibia. One threaded commercially pure titanium implant was inserted in each patello-femoral joint flush to the cartilage. Six weeks after implant insertion measurement of the peak removal torque necessary to loosen the implants and light microscopical histomorphometrical investigations of tissue integration were performed. In the ovariectomized rabbits addition of sodium fluoride to the cement resulted in increased area of bone in the threads (p=0.04), but no corresponding effect could be noted in the controls. The removal torque was lower in the ovariectomized rabbits compared to the non-ovariectomized when comparing implant with sodium fluoride addition (p=0.02). The bone tissue response and the removal torque of the titanium implants were not influenced by ovariectomy in these rabbits.

Journal Article↗

Active-site titration of serine proteases using a fluoride ion selective electrode and sulfonyl fluoride inhibitors.

We report a general procedure for the determination of active enzyme concentrations for serine proteases. The method relies on the measurement of fluoride ion released from sulfonyl fluorides upon reaction with the active-site serine using an ion selective electrode. The results have been independently confirmed by amino acid analyses of subtilisins and by spectrofluorometric and spectrophotometric titrations. The minimal enzyme concentration detectable is 1-10 microM protease. The method is insensitive to color and turbidity of the sample and is therefore useful for measuring protease concentration in broth solutions. The active enzyme concentration of subtilisin BPN' from Bacillus amyloliquefaciens determined by titration with phenylmethylsulfonyl fluoride is 25% higher than the concentration determined using the spectrophotometric burst titrant N-trans-cinnamoylimidazole. Analysis of the pre-steady-state burst amplitude and kinetics suggests that the extinction coefficient for the cinnamoyl acyl-enzyme is larger than previously measured and a significant fraction of the enzyme is present as an unproductive ES2 complex. The molar extinction coefficient at 280 nm for subtilisin BPN' is 26.5 mM-1 cm-1 and for subtilisin from Bacillus lentus is 22.5 mM-1 cm-1.

Bacillus↗

Bioavailability of fluoride in postmenopausal women: comparative study between sodium fluoride and disodium monofluorophosphate-calcium carbonate.

Fluoride (F) increases trabecular bone mass and can be used in the treatment of osteoporosis with crush fractures. As the bioavailability of sodium fluoride (NaF) can be impaired by concomitant absorption of calcium, both drugs have to be ingested separately. However, disodium monofluorophosphate-calcium carbonate (MFP-Ca), another F compound, allows a single administration. In a cross-over randomized study, we compared the bioavailability of both drugs under regular conditions of prescription. Ten postmenopausal women (aged 48-77 years) with glomerular filtration rate (GFR) greater than 70 ml/minute and without bone disease entered the study. Each received 25 mg of NaF [i.e., 11.3 mg F ion (F-)] fasting and 100 mg of Na2FPO3-1250 mg CaCO3 (i.e., 13.2 mg F-) with breakfast in a single dose separated by an 8-day washout. After dosing, plasma F levels and fractionated and total urinary F collection were determined during a 24-hour period using a specific electrode. Results show a significant shorter lag time absorption (Tmax = 1.4 +/- 0.2 hour) and a higher maximal concentration (Cmax = 260 +/- 60 ng/ml) for MFP-Ca than for NaF (Tmax = 2.5 +/- 0.4 hour; Cmax = 200 +/- 85 ng/ml). However, areas under curve (AUC) for MFP-Ca (1711 +/- 195 micrograms/liter/hour) and for NaF (1202 +/- 147 micrograms/liter/hour) were not significantly different. The relative bioavailability of both F compounds related to their fluoride content (i.e., 1.22 for AUC ratio) was equivalent, according to the Westlake method. These data provide the first evidence of comparable bioavailability of two F compounds in a population of postmenopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

In vitro release and in vivo serum fluoride levels and urinary excretion after different sodium fluoride tablets.

Various sodium fluoride tablets used for the treatment of osteoporosis were evaluated. The tablets were characterized in vitro by determining the release curves. The serum levels and urinary recovery of fluoride were determined after a single oral dose either of rapidly soluble (conventional), sustained release or enterocoated tablets. The in vivo study showed that administration of sustained release tablets eliminated high serum peaks and prolonged the duration of an elevated serum level as compared to conventional tablets. The biovailability of the fluoride was lower after intake of sustained release and enterocoated tablets, and there was an increase in the interindividual variance of biovailability.

Adult↗

Bone fluoride concentrations associated with fluoridated drinking water.

Recently published bone fluoride values from Iowa are very high compared to earlier reports, suggesting an increase in fluoride intake. Reanalysis of the Iowa specimens shows levels one-fourth those reported by the Iowa laboratory indicating an error in the original report. Seventeen bone specimens, collected from long-term residents of Rochester, New York, drinking 1 ppm F- water, had a mean value of 2085 +/- 270 ppm F- on an ashed-weight basis. This value is not significantly different from that predicted by the data of Zipkin et al. in 1958. These data, therefore, do not support the contention that there has been an increase in fluoride intake.

Bone and Bones↗

Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 1: Fluorides.

Radiation-induced xerostomia results in significant changes in the oral cavity particularly oral microbial changes, which include a marked increase in the number of cariogenic organisms, notably Streptococcus mutans and lactobacillus species. This loss of the capacity to secrete saliva creates or promotes the rapid onset and progression of rampant dental caries. In this 2-part series, the benefit of fluoride in reducing caries activity is presented. Part 1 discusses the historical and currently available fluoride preparations and Part 2 presents data of a recently completed trial investigating the benefit of an intraoral sodium fluoride releasing system.

Anti-Bacterial Agents↗

Desmond Greer Walker Award. Enamel mottling in a non-fluoride community since the advent of fluoride toothpastes.

In 1987 an assessment of mottling in incisor teeth was carried out on a random sample of 12-year-old children in Liverpool, England. The number of children examined was 471. All of these children were born and had lived in Liverpool when the fluoride content of the water supply had averaged 0.1 parts/10(6). During this time the market share of fluoride toothpastes had increased from 5% in the early 1970s to 91.8% in 1987. The mouth prevalence of mottling was found to be 31.1%. The tooth prevalence of mottling was found to be 7.83%. There was no sex difference. The data obtained was compared with findings in 1974-75 in Liverpool before the advent of fluoride toothpastes. The data suggests that there has been a decrease in the prevalence of mottling in Liverpool since 1974-75.

Chi-Square Distribution↗

A review on fluoride varnishes: an alternative topical fluoride treatment.

The in vitro, in vivo and clinical research on topical fluoride varnishes in surveyed. The probable mechanisms of action for fluoride varnishes is discussed and this effect demonstrated from the results of in vitro and in vivo research. Findings from clinical studies are summarized and selected results are used to estimate expected preventive effects from the treatment. The practical advantages and limitations of fluoride varnishes are also reviewed and indications for the future used of these preventive agents are considered.

Adult↗

Three-year caries increments after fluoride rinses or topical applications with a fluoride varnish.

251 9-12-yr-old children completed a 3-yr, double-blind, clinical trial of two caries preventive fluoride programs. Caries increments and progression patterns were compared in two groups of children who rinsed every fortnight with a 0.2% NaF solution or received biannual topical applications with a fluoride varnish (Fluor-Protector). Clinically recorded mean DFS increments were 3.3 +/- 0.2 (SE) in the rinse group and 3.5 +/- 0.2 in the varnish group. In both groups nearly half of these increments were recorded in the occlusal surfaces of second molars. The mean incremental DFS recorded radiographically on approximal surfaces of posterior teeth were 1.1 +/- 0.2 and 1.5 +/- 0.2 in the rinse and varnish group, respectively. None of the inter-group differences were statistically significant (P greater than 0.05). Detailed analyses of the radiographic scores revealed a similar and extremely slow caries progression in the two study groups and they strengthened the conclusion of equal clinical efficacy of the two treatments. None of the fluoride programs had been able to change preestablished patterns of caries development among the children.

Child↗

Fluoride reactions with dental enamel following different forms of fluoride supply.

The reactions with dental enamel of NaF as tablets dissolved in different beverages or supplied with NaCl, simulating domestic salt fluoridation, were studied in tests with enamel surfaces and enamel powder. It was confirmed that powdered enamel can react quite differently from enamel surfaces under certain conditions. Enamel surfaces took up much more fluoride (F) from orange juice than from water or milk, and neither the low pH nor the citrate content of the juice increased the formation of unstable CaF2 in the enamel, as judged from a KOH leaching test. The F uptake by enamel surfaces from 0.25 mM NaF in 175 mM NaCl, corresponding to a dish prepared with salt containing 500 parts/106 F, was about 80% greater than from the same NaF concentration in water. This NaCl concentration did not increase the formation of CaF2 in the enamel, as judged from the KOH test, while 350 mM NaCl caused a moderate increase. The investigations support the administration of NaF tablets with orange juice and plans for domestic salt fluoridation.

Adult↗

Fluoride concentrations in saliva after single oral doses and their relation to plasma fluoride.

The saliva and plasma fluoride (F) concentrations following intake of different doses of fluoride tablets were studied in six subjects. There was a close relationship between saliva F and plasma F and the ratio was 0.64 +/- 0.01 (s.e.). The plasma half life of F was 4-16 h. This results indicate that saliva F may be a useful substitute for blood sampling in studies concerning the pharmacokinetics of fluoride.

Administration, Oral↗

Skeletal development and dental fluorosis in 12--14-year-old Danish girls from a fluoride and a non-fluoride community.

The present study has examined the relationship between waterborne fluoride, dental fluorosis and skeletal maturity in two Danish areas containing less than 0.2 and 2.4 parts/10(6) F- in the drinking water. 12--14-year-old girls, 113 from the non-F- area and 122 from the F- area, born and raised in the areas, were examined. No relationship could be found between skeletal maturity and fluoride content of the drinking water. The association between the severity of dental fluorosis and skeletal maturity in the girls from the F- area was not statistically significant, but the tendency followed the same pattern as observed in tropical high and low fluoride areas.

Adolescent↗