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PubMed1997

[Exposure of Poznan inhabitants to fluorides. II. Fluorides in urine and hair of school children].

In view of the plans of fresh water fluoridation in Poznań the necessity arose of obtaining of information about the exposure to fluoride compounds. The reported study was carried out in Poznań and environs. Urine and hair samples of children were obtained. The determinations were done with a ion- selective electrode. The mean fluoride concentrations in urine were between 0.3 and 0.9 mg F-/dm3. The concentration in hair was 2.2 mg F-/g in Poznań and 3.3 mg F-/g in Luboń. These values were, however, not exceeding the acceptable ones. In Luboń the concentrations of fluorides in hair was 50% higher than in Poznań. The authors believe that the possible cause was Fertilizer Chemical Works in that location.

Air Pollutants↗
PubMed2000

Fluoride-induced ultrastructural changes in exocrine pancreas cells of rats: fluoride disrupts the export of zymogens from the rough endoplasmic reticulum (rER).

Influence of fluoride on exocrine pancreas cells was examined morphologically with traditional and prolonged osmium fixation techniques for electron microscopy in the enamel fluorosis model rats injected subcutaneously twice a day with 20 mg/kg body weight of sodium fluoride. Although the rough endoplasmic reticulum (rER) of exocrine pancreas cells in control rats was laminated and oriented parallel to the circumference of the nucleus, the rER of the cells in NaF-treated rats was dilated, disrupted the laminated arrangement, and changed to the globular-shape rER. Many intracisternal granules were formed in these globular-shape rER of the cells exposed to fluoride. Lots of autophagosomes were also seen in the exocrine cells with NaF treatment. The autophagosomes were limited with a double or multiple membranes, and contained cytoplasmic organelles and/or the intracisternal granules. The outer and inner leaflets of double membranes of the autophagosomes were usually separated by a distinct electron-lucent area. In prolonged osmium fixation, the area between the double membranes of the autophagosome was filled with osmiun reaction deposits. Many autophagosomes were encircled with the single or multiple osmiophilic layers. In some cases, the osmium positive saccules also surrounded the free surface of the globular-shape rER containing intracisternal granules. These findings indicate that fluoride disrupts the export of zymogens from the rER, resulting in formation of intracisternal granules and autophagosomes, and that the osmiophilic saccules participate in sequestration of cytoplasmic organelles in forming autophagosomes.

Animals↗
PubMed1998

Mechanism of toxic action of fluoride in dental fluorosis: whether trimeric G proteins participate in the disturbance of intracellular transport of secretory ameloblast exposed to fluoride.

In enamel fluorosis model rats treated with sodium fluoride, secretory ameloblasts of incisor tooth germs exhibited disruption of intracellular trafficking. We examined whether heterotrimeric G proteins participated in the disruption of vesicular trafficking of the secretory ameloblast exposed to fluoride, using immunoblotting and pertussis toxin (IAP)-induced adenosyl diphosphate (ADP)-ribosylation for membrane fractions of the cell. Immunoblotting of crude membranes, post supernatants of the ameloblast, with anti-G(alpha i3/alpha o) and anti-G(alpha s) antibodies showed that Gi3 or Go proteins existed in the secretory ameloblast, but Gs protein did not. Immunoblotting of the subcellular membrane fractions indicated that the Gi3 or Go proteins were located in the Golgi membrane, but were not in the rough endoplasmic reticulum (rER) membrane. Autoradiograph of IAP-induced ADP-ribosylation, however, showed the existence of IAP-sensitive G proteins both in rER and Golgi membranes. Fluoride treatment decreased the G proteins bound to both membranes. These findings indicate that different G proteins, both of which are IAP-sensitive, are present in the rER and Golgi apparatus, and suggest that these G proteins participate in the disturbance of intracellular transport of the secretory ameloblast exposed to fluoride.

Adenosine Diphosphate Ribose↗
PubMed2005

Beneficial effect of copper supplementation on deposition of fluoride in bone in fluoride- and molybdenum-fed rabbits.

Fluorosis is a major public health problem in the world, including India. The present study was undertaken to investigate the role of molybdenum (Mo) in the deposition of fluoride (F) in bone and whether copper (Cu) supplementation has any alleviating role when F and Mo are ingested together. For this purpose, four groups of rabbits were used [control (C), fluoride (F), fluoride + molybdenum (F + Mo), and fluoride + molybdenum + copper (F + Mo + Cu)] to find out the effect of these treatments on various bone-related parameters like intact parathyroid hormone (iPTH), alkaline phosphatase and Cu in serum, hydroxyproline and calcium (Ca) in urine, and minerals (F, Cu, manganese, and zinc) in femur bone ash. Bone mineral content (BMC), bone mineral density (BMD) [by dual energy X-ray absorptiometry (DXA)], and strength of femur bones were also assessed. F content in the femur was significantly higher (P < 0.01) in all experimental groups compared to control group. Mo supplementation increased F deposition in femur bone in the F + Mo group, whereas supplementation of Cu reduced F deposition in the F + Mo + Cu group compared to the F + Mo and F groups. Levels of Cu in femurs of the F + Mo and F + Mo + Cu groups were significantly higher (P < 0.05, P < 0.01, respectively) than in the C group, although serum Cu was significantly lower in the F and F + Mo than the C and F + Mo + Cu groups. Magnesium levels in the F + Mo group were significantly higher (P < 0.05) than in the F and F + Mo + Cu groups. Cu supplementation in the F + Mo + Cu group increased deposition of zinc significantly (P < 0.05) compared to the F and F + Mo groups. Serum iPTH, alkaline phosphatase, and urinary hydroxyproline and Ca were significantly higher (P < 0.01) in the F and F + Mo than in the C and F + Mo + Cu groups. However, serum iPTH and urinary hydroxyproline were higher in the F + Mo group than the F group. Alkaline phosphatase was significantly higher in the F + Mo group than the F and F + Mo + Cu groups. Levels of serum Cu in the F and F + Mo groups were lower than in the C group, though serum Cu was significantly higher in the F + Mo + Cu than in all other groups. DXA analysis of femur bone indicated that BMD in the F + Mo group was significantly higher than in the F (P < 0.05), C (P < 0.01), and F + Mo + Cu (P < 0.05) groups. However, there was no significant difference in BMC among the groups. Bone strength was significantly higher (P < 0.05) in the F + Mo group than in the C group. Results of the present study show that ingestion of Mo with F does not create secondary Cu deficiency (due to increased excretion of Cu through urine). However, Cu concentration was decreased in serum in this group (F + Mo) compared to the C and F + Mo + Cu groups. Deposition of F in femur bone was more (22%) when it was given along with Mo compared to F alone, while F deposition in femur bone was less in the F + Mo + Cu group by 80% compared to the F group. Also, deposition of F in the F + Mo + Cu group was 120% less compared to the F + Mo group. The increase in F level due to Mo addition appears to be offset by supplementation with Cu. Supplementation with Cu showed a beneficial effect on bone resorption as well as bone formation.

Alkaline Phosphatase↗
PubMed1992

Enamel fluoride uptake from an experimental fluoride-releasing orthodontic adhesive.

The purpose of this study was to evaluate quantitatively the fluoride uptake by enamel from an experimental visible light-cured orthodontic adhesive (VP-862) based on YbF3 filler. Sixteen contralateral premolars were extracted from 10 orthodontic patients and were classified in four groups (A, B, C, D) of four buccal surfaces each. Standardized enamel areas located on these surfaces were acid etched and were subjected to the following adhesive treatments: (A) VP-862; (B) Heliosit Orthodontic; (C) Heliobond + VP 862; and (D) Heliobond + Heliosit Orthodontic. Groups B and D were used as a reference. After 9 months in vivo, the teeth were extracted and cross-sectioned, and the enamel-adhesive interfaces were studied by combined wavelength-energy dispersive electron probe microanalysis. According to the results, the cumulative fluoride uptake by enamel from the experimental adhesive was not statistically different from the fluoride detected in the reference groups. No effect of the liquid resin, Heliobond, on the fluoride uptake gradients of enamel could be differentiated.

Acrylates↗
PubMed1990

X-ray crystal structure of the fluoride derivative of Aplysia limacina ferric myoglobin at 2.0 A resolution. Stabilization of the fluoride ion by hydrogen bonding to Arg66 (E10).

The X-ray crystal structure of the fluoride derivative of Aplysia limacina ferric myoglobin has been solved and refined at 2.0 A resolution; the crystallographic R-factor is 13.6%. The fluoride ion binds to the sixth co-ordination position of the heme iron, 2.2 A from the metal. Binding of the negatively charged ligand on the distal side of the heme pocket of this myoglobin, which lacks the distal His, is associated with a network of hydrogen bonds that includes the fluoride ion, the residue Arg66 (E10), the heme propionate III, three ordered water molecules and backbone or side-chain atoms from the CD region. A comparison of fluoride and oxygen dissociation rate constants of A. limacina myoglobin, sperm whale (Physeter catodon) myoglobin and Glycera dibranchiata monomeric hemoglobin, suggests that the conformational readjustment of Arg66 (E10) in A. limacina myoglobin may represent the molecular basis for ligand stabilization, in the absence of a hydrogen-bond donor residue at the distal E7 position.

Animals↗
PubMed1998

Heterogeneous fluoridated apatites synthesized with a three-step fluoride supply system.

Two types of heterogeneous fluoridated apatite, H-F-H and F-H-F, were synthesized by supplying fluoride during the middle half (H-F-H) or initial and final quarters (F-H-F) of the experimental period. Although X-ray diffraction patterns and SEM photographs of both H-F-H and F-H-F-type apatites were not significantly different, high-resolution transmission electron microscopy showed quite different features; H-F-H-type apatite crystals were elongated hexagons, while those of F-H-F-type apatite were rather wider hexagons with electron damage in three-quarters of the inner core. These results supported the previous speculations on the two different types of heterogeneous fluoridated hydroxyapatites synthesized with fluoride concentrations stoichiometrically equivalent to that of fluorapatite: hydroxyapatite covered with fluorapatite and fluorapatite covered with hydroxyapatite. F-H-F-type apatite was less soluble than that of H-F-H-type apatite.

Apatites↗
PubMed1998

In situ de- and remineralisation of enamel in response to sucrose chewing gum with fluoride or non-fluoride dentifrices.

OBJECTIVES: Enhancement of the remineralisation of artificial enamel lesions has been observed in an intraoral model whether subjects chewed gum sweetened with a non-cariogenic sweetener such as sorbitol [1-3] or sucrose [4] after meals or snacks, and with use of a conventional (1500 ppm F) fluoride dentifrice. Since most of the clinical surveys which have shown the potential cariogenicity of sucrose chewing gum [5] were conducted before use of fluoridated dentifrices became widespread, the effect of fluoride dentifrice on de- and remineralisation of artificial lesions in enamel in response to chewing sucrose-sweetened gum has been examined with the aim of attempting to resolve this apparent discrepancy. METHODS: Subjects wore an intraoral device bearing an enamel lesion and chewed one piece of sucrose gum for 20 min after each of three meals and two snacks daily for two 3-week periods, during which they used a dentifrice containing either 0 or 1500 ppm F in a double-blind, cross-over design. Measurement of the mineral content of the lesions was determined by microradiography or polarised light microscopy. RESULTS: It was found that remineralisation tended to occur with 1500 ppm F dentifrice, but demineralisation with non-F dentifrice; the difference in enamel mineral content between the two periods was significant (P < 0.05). CONCLUSIONS: The results indicate that the potential cariogenicity of sucrose-containing chewing gum may indeed be negated by the use of a conventional fluoride dentifrice.

Adolescent↗
PubMed1985

Plaque growth-inhibiting effects of an abrasive fluoride-chlorhexidine toothpaste and a fluoride toothpaste containing oxidative enzymes.

The aim of this 4 times cross-over double-blind clinical trial was to test the plaque-inhibiting effect of 2 fluoride-containing toothpastes. One toothpaste contained 0.8% chlorhexidine together with amine fluoride (0.1% F degrees) and a suitable abrasive agent. The other contained 1.7 U/g glucose oxidase and 8.0 U/g amyloglucosidase, added to an amine fluoride (0.1% F degrees) toothpaste. 1% Hibitane dental gel was used as a positive and a conventional fluoride toothpaste (Vademecum MFP Fluor) as a negative control. 9 dental students, in a randomized sequence, applied the 4 dentifrices twice daily from Monday afternoon to Friday morning with cap splints, designed to cover the teeth and about 2 mm of gingiva. No other oral hygiene measures were allowed during the 4 test periods. On Fridays, the teeth were cleaned professionally and good oral hygiene was maintained during the week-ends. At the beginning and at the end of each test period, per student plaque thickness was recorded using the plaque index, the visible plaque index, and plaque fresh weight as parameters, and the area of plaque as related to the area of the tooth surface was recorded planimetrically and according to the PLQ index. The best plaque growth-inhibiting effect was recorded for the positive control (CHX) with the test chlorhexidine toothpaste (TX) as next best. The enzyme-containing toothpaste (TE) did not differ significantly from the negative control (C). All the significant differences in anti-plaque effect between the 4 toothpastes were obtained by recordings of plaque thickness and none on the basis of area of plaque.

Chlorhexidine↗
PubMed1985

Longitudinal study of prevalence of enamel lesions in a fluoridated and non-fluoridated area.

The aim of this study was to examine longitudinally the effect of water fluoridation on the prevalence of enamel lesions in children 7-18 yr of age. 93 children in Tiel (1 ppm F-) and 103 children in Culemborg (0.1 ppm F-) were examined every other year at 7, 9, 11, 13 and 15 yr of age. A supplementary examination was carried out when these children reached the age of 18. Children in Tiel had access to water fluoridation from birth. The total number of lesions, including enamel lesions, on the buccal as well as on the occlusal surfaces was approximately the same in both areas in children 15 and 18 yr of age. Approximal lesions were scored on standardized bitewing radiographs. A large proportion of enamel lesions could not be detected on radiographs. In a fluoridated area a high percentage of all lesions remain in the stage of enamel caries lesions. On buccal surfaces 93% and on approximal surfaces 86% of all lesions had not progressed into the dentin. In Culemborg these percentages were 65 for approximal as well as for buccal surfaces. At the initiation of lesions, at younger ages, only a small retardation of the process was observed, but caries progression beyond the stage of enamel caries was markedly reduced in the fluoridated area. No pre-eruptive effect could be observed if the total number of lesions, including enamel lesions, from Tiel and Culemborg were compared.

Adolescent↗
PubMed1976

Fluoride release from a fluoride-containing amalgam and two luting cements.

The release of fluoride from an amalgam and two luting cements, silicophosphate and polycarboxylate, was studied by shaking test specimens in a solution with hydroxyapatite, and measuring the fluoride taken up by the apatite. The initial release was significant for all three materials. After 1 week the amalgam released only minor amounts of fluoride, whereas the cements continued to liberate fluoride during the 5-week observation time to the same extent as silicates in earlier studies.

Dental Amalgam↗
PubMed1976

Permeability and fluoride release of lining materials containing amine fluorides.

The addition of amine fluorides to a copal recin (Copalite) and a chlorine caoutchouc varnish (Pergut S-40) has been studied. The permeability of Copalite films was only slightly increased whereas the excellent film-forming qualities of Pergut S-40 were destroyed by the addition of fluorides. A high fluoride release was found initially from test films of the materials but within 2-3 weeks a decrease to very low fluoride levels was observed.

Amines↗
PubMed1997

Irradiation effects on microhardness of fluoridated and non-fluoridated bovine dentin.

The objective of this study was to evaluate the effects of irradiation on microhardness of dentin. Dentin blocks from the cervical region of bovine incisors were treated as follows: (1) no irradiation; (2) irradiation of specimens up to 60 Gy (2 Gy/day, 5 days/week); (3) no irradiation, but fluoridation of specimens for 5 min/d; (4) irradiation of specimens and daily fluoridation. Knoop hardness number (KHN) of the control specimens was 62.63+/-14.75 (mean+/-SD). This was significantly different from the irradiated dentin samples (8.74+/-2.59 KHN). Hardness of the fluoridated dentin specimens was 11.19+/-1.95 KHN in the non-irradiated group and 10.03+/-2.76 KHN in the irradiated groups, respectively. Within the limitations of an in vitro study, it is concluded that dentin is severely affected by irradiation. This could be an explanation for the frequently observed side-effects of irradiation like loss of enamel, gap formation at the amelodentinal junction, and caries of the cervical region. Fluoridation with acidic gels decreases microhardness of dentin surface, and does not prevent softening due to radiation, when saliva is absent.

Animals↗
PubMed1990

Community water fluoride levels, preschool dietary patterns, and the occurrence of fluoride enamel opacities.

Three hundred seventy-four 12- to 14-year-old children were examined to determine modified tooth surface index of fluorosis (TSIF) scores, and to assess the association among fluoride enamel opacities and water fluoride levels, preschool dietary patterns, and dentifrice consumption. The subjects included boys and girls of both black and white races who reported life-long residence in either Augusta or adjoining Richmond County. "City" children had communal water consistently fluoridated at levels of 0.9 to 1.2 ppm. "County" children had water variably fluoridated at levels of 0.2 to 0.9 ppm. TSIF scores were recorded on each included tooth and the highest TSIF tooth score was noted for each subject. The frequency of TSIF scores in all subjects was analyzed for dental arch symmetry and for association with city/county residence. The frequency of TSIF scores then was analyzed separately for "city" children and "county" children for an association with race, gender, preschool dietary habits, and dentifrice ingestion. Chi-square analysis revealed that higher TSIF scores were associated with city children significantly more than with county children. There was no association of TSIF scores either in the city children or the county children with respect to gender, race, preschool dietary patterns, or dentifrice ingestion. TSIF scores were bilaterally symmetrical, but were higher in the maxillary arch than in the mandibular arch.

Adolescent↗
PubMed1990

Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after five years.

This article presents five-year interim findings of an eight-year clinical trial designed to compare the relative caries-preventive benefits of weekly fluoride mouthrinsing, daily fluoride tablet administration, and both procedures combined. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly in school to one of three groups that (1) rinses once a week in school with a 0.2 percent neutral NaF solution; (2) chews, rinses with, and then swallows daily in school a neutral 2.2 mg NaF tablet; or (3) carries out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. After five years, 789 children were available for reexamination. Findings show that subjects in the combination group experienced a mean caries increment of 1.47 DMFS, 16.5 percent lower than the mean score of 1.76 DMFS for children in the tablet group and 31.3 percent lower than the 2.14 DMFS for those in the rinse group. Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant (P less than .05). Despite the finding of an additive caries-preventive benefit among children who followed the combined regimen, it would be premature to judge which procedure is best before results of the final examinations become known.

Child↗
PubMed1996

An in vitro study of the distribution of silver and fluoride following application of 40 per cent silver fluoride solution to dentine.

An in vitro test system involving application of 40 per cent silver fluoride solution to prepared cavities of moderate depth in extracted teeth failed to demonstrate the passage of significant amounts of fluoride into the dental pulp, despite a very high concentration of fluoride (100,000 ppm) in the applied solution. The test system used may not be conducive to quantitative investigation of ionic transfer because of disruptions to pulp circulation and fluid flow through dentine following tooth extraction. For this reason, the results are inconclusive as to whether or not application of 40 per cent silver fluoride as a cavity varnish of liner and its use in the 'atraumatic' technique for treating deep caries, can be considered safe clinical procedures.

Adolescent↗
PubMed1982

The nonlinear tissue-binding character of fluoride kinetics in normal and anephric subjects. Graphical analysis of serum fluoride data from man and rabbit.

A study has been made of the fluoride kinetics in man, with a series of 5 healthy subjects and 4 patients with renal insufficiency. The fluoride metabolism was found to conform to nonlinear tissue-binding kinetics. Reanalysis of findings on the rabbit reported in the literature yielded equivalent results. The tissue-binding constants elicited - probably associated with the fluoride metabolism of bone - presented no differences between healthy subjects and uremics. Uremics had a clearly lower fractional fluoride elimination rate (K) compared with the healthy controls. A significant correlation of creatinine clearance on the K value was noted.

Adult↗
PubMed1994

In situ remineralization of root surface lesions using a fluoride chewing gum or fluoride-releasing device.

The in situ remineralization of early root surface lesions was studied using a fluoride-releasing device (FRD) or a fluoride chewing gum. Root specimens with subsurface lesions were mounted in removable lower appliances in 6 adult subjects. Test groups chewed five sticks/day (0.1 mg F/stick) or one FRD (0.5 mg F/day release rate) was mounted in the midline of the appliance. A fluoride-free dentifrice was used three times/day for each 21-day control and the two test regimens. Separate root lesions were used to measure fluoride uptake or changes in mineral content by quantitative microradiography. Comparable values for percent remineralization for both FRDs and F gum were higher than controls, and the F uptake for FRDs exceeded both the F gum and controls (p = 0.05).

Adult↗