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PubMed2001

An ex vivo investigation into the fluoride release and absorption profiles of three orthodontic adhesives.

Prevention of peri-bracket decalcification is essentially mediated by effective oral hygiene, which is patient dependent. The potential to compensate for poor oral hygiene may be through the release of free fluoride ions from direct bonding agents. It is well established that glass ionomer cements (GICs) release free fluoride ions which may be replenished by exposure to fluoride containing solutions. The aim of this ex vivo study was to compare the fluoride release and absorption profiles of a recently developed low fusion, monophase GIC, Limerick glass, with two materials in common clinical use, namely, Fuji-Ortho L.C. and Concise. Ten test specimens of each material were fabricated and stored in deionized water at 37 degrees C. The concentration of fluoride release was measured daily for the first 7 days after immersion and then weekly for 5 weeks. On day 42 the test specimens were recharged in 2 per cent sodium fluoride solution and fluoride release was measured initially after 24 hours and then every 48 hours. The recharge regimen was repeated for 3 weeks. Both Limerick glass and Fuji-Ortho L.C. demonstrated the characteristic fluoride release pattern of GIC with a rapid elution of fluoride after the first 24 hours followed by a more gradual release profile over the following 2 weeks. Fuji-Ortho L.C. released the greatest quantity of fluoride but the release profile of Limerick glass was more sustained. Concise released negligible amounts of fluoride. Limerick glass and Fuji-Ortho L.C. showed an increase (P < 0.01) in fluoride release following exposure to 2 per cent sodium fluoride that decreased both with time and subsequent exposures to fluoride supplement.

Absorption↗
PubMed1984

Use of fluorides by Finnish adolescents.

According to the recommendations of the National Board of Health in Finland fluoride tablets should be used daily from the age of 6 months to 15 yr in fluoride deficient areas. Topical fluorides are recommended in addition to systemic fluorides. The aim of this study was to analyze the use of fluoride tablets and topical fluorides by Finnish adolescents. Teenagers (n = 4705) representing Finnish youth aged 12, 14, 16 and 18 yr were sent mail questionnaires in February 1981. The response rate was 88%. The proportion of daily fluoride tablet users was 12% among 12-yr-old girls, 3% among 14-yr-old girls and among boys 10% and 4%, respectively. Fluoride rinses at home were used daily by only 1%. During the most recent school term, 34% had several times, and 8% once, participated in classroom fluoride rinsing. In the same period 14% had used fluoride gel several times, and 10% once. Thus despite dental health education, fluoride tablets and rinses are used very rarely at home by Finnish teenagers. The recommendations of the National Board of Health are far removed from the behavior of adolescents. Use of fluoride tablets and topical fluorides do not seem to be a practical alternative to drinking-water fluoridation, because of the low level of compliance.

Adolescent↗
PubMed1997

Fluoride in plaque fluid and saliva after NaF or MFP rinses.

A micro-analytic method, capable of measuring the fluoride concentration in 5 nl of plaque fluid, was used to follow changes in fluoride concentration in saliva and plaque fluid at 6 single tooth-sites in 6 subjects for 180 min after a 0.048 M fluoride rinse as a NaF or MFP (sodium monofluorophosphate) solution. The maximum fluoride concentrations in saliva after NaF was 13x higher than with MFP. About 5% of the total amount of fluoride following the 20 ml NaF rinse was retained in the oral cavity. The corresponding figure followig MFP was <1%. The saliva/plaque fluid fluoride ratios for upper molars and lower incisors were significantly higher than for the upper incisors and lower molars. There was a tendency for a decline in the ratios with respect to time for all sites. To characterize the plaque fluid fluoride intra-oral single-site distribution and clearance, fluoride concentration versus time (AUC) was calculated from 10 to 60 min after a rinse. The NaF AUC followed the order: upper incisor, lower molar, upper molar and lower incisors reflecting a different exposure and clearance pattern due to the different access of the plaque to saliva. The MFP AUC values varied more, but were all significantly lower than the NaF AUC values. Analysis of plaque fluid fluoride curves at various sites revealed an exponential decline in most cases. With NaF, the baseline plaque fluid fluoride levels were not reached within 3 h. It is concluded that NaF solutions result in a significantly higher intra-oral fluoride exposure than MFP solutions. The fluoride distribution and clearance of fluoride from different sites in the oral cavity are linked to salivary access to these sites. These site-specific differences may have clinical consequences with regard to the dynamics of fluoride in the de- and remineralization processes.

Adult↗
PubMed1990

Fluoride exposure in Michigan schoolchildren.

Recent trends in the prevalence of dental caries in children, as well as a possible increase in the prevalence of dental fluorosis, have prompted some researchers to suggest the reassessment of water fluoride concentration standards. Instead of reducing water fluoride concentrations, an alternative approach would be to limit the use of, or reduce the fluoride concentration of, dentifrices, mouthrinses, and supplements. Information about the use of these other sources of fluoride, however, is scarce. Using data from a 1987 survey of Michigan schoolchildren, exposure to selected fluoride sources as well as toothbrushing habits are described. Responses from questionnaires revealed that, overall, 98.5 percent of the children have used fluoride dentifrices, 27 percent have used topical fluoride rinses, 72.5 percent have had at least one exposure to professionally applied topical fluoride, and 27 percent have used dietary fluoride supplements. Although the use of fluoride dietary supplements was appropriate for most children residing in fluoride-deficient Cadillac, the percentages of children in the other communities who have ingested these supplements suggest that these products are being prescribed improperly. Given the almost universal use of fluoride dentifrices at an early age, it may be time to investigate the use of reduced fluoride dentifrices for children. In addition, continuing efforts to decrease inappropriate dietary fluoride supplementation are required.

Age Factors↗
PubMed1996

Water fluoridation results in Basel since 1962: health and political implications.

The population of the canton Basel-City has been provided with fluoridated water since May 1962. This paper presents a summary of basic findings from evaluations of this public health intervention. Standard methods were used for assessing dental caries, enamel fluorosis, urinary fluoride, and other data. Caries prevalence of schoolchildren declined until 1977 because of water fluoridation, after which it continued to decline until the late 1980s due to reasons other than water fluoridation. Caries prevalence in Basel was at least as low as in those other parts of Switzerland where either school-based dental health education programs or comprehensive salt fluoridation programs had been implemented for many years. Enamel fluorosis was seen in 38 percent of the children, similar to regions with comprehensive salt fluoridation, but higher than in low-fluoride regions. Overlap of salt and water fluoridation in families consuming both fluoridated water and fluoridated salt has occurred, but has not resulted in problems. Fluoride concentrations (close to, but mostly below 1.0 ppm) and excretions (0.45-0.80 mg F per day in children, around 1 mg in adults) corresponded to expected levels. Statistics from both the School Dental Service and the Public Dental Clinic indicate a dramatic reduction in the amount of conservation dentistry being done and, in adults, prosthetic services. Political steps to remove water fluoridation were taken in 1976, 1982, 1989, and 1993, but have not been successful. Water fluoridation has resulted in the expected benefit and continues to exist beside salt fluoridation used in the other cantons of Switzerland.

Adolescent↗
PubMed2000

Fluoride release from a toothbrush.

The purpose of the present study was to evaluate the fluoride concentration in unstimulated saliva after using a toothbrush with 9,048 ppm fluoride as sodium fluoride incorporated in the bristles. A toothpaste with 1,500 ppm fluoride served as the positive control. Twelve volunteers took part in the single-blind crossover study. In a pre-test phase of 14 days, the subjects refrained from eating fluoride-rich foods and did not use any fluoride-containing products for oral hygiene measures. This was followed by a test period of four weeks. At day one and after 14 and 28 days, unstimulated saliva was collected and analyzed for its fluoride content. Saliva was collected immediately after toothbrushing and after 15, 30, 60, 90, 120 150, and 180 minutes. On day one, the fluoride toothbrush released significant amounts of fluoride immediately after the brushing, and after 15 and 30 minutes (p < 0.01). After 14 days of use, this could be found immediately after brushing and after 15 minutes (p < 0.01 or p < 0.05, respectively). After 28 days, a significant fluoride release was only found immediately after brushing (p < 0.05). On all days, compared to the positive control, the fluoride release from the fluoride toothbrush was generally lower immediately after brushing and after 15 minutes (p < 0.001, p < 0.01 or p < 0.05, respectively). It may be concluded that a toothbrush with incorporated sodium fluoride could act as a fluoride-releasing. device.

Cariostatic Agents↗
PubMed1989

Dietary fluoride supplements for Tennessee's children: the role of the physician.

1. All children should receive some form of systemic fluoride and appropriate forms of topical fluoride. 2. If a child is not receiving optimally fluoridated water, the physician or dentist should prescribe a dietary fluoride supplement as tablets or drops. 3. The correct dosage must be determined, based on patient age and fluoride content of the patient's drinking water. 4. Special attention is necessary concerning fluoride intake for children breast-feeding or consuming infant formula. 5. To arrive at the correct fluoride dose, these steps should be followed: (A) Whenever you do not have specific knowledge of water fluoride content, have a sample of the main drinking water source (usually home water) analyzed for the fluoride content before prescribing a fluoride supplement. (B) When the fluoride content of the water has been determined, the fluoride level and the child's age should be matched on Table 1 to arrive at the correct supplement dose. 6. The Fluoridation Program of the Tennessee Division of Water Supply can provide lists of communities and schools in Tennessee that are optimally fluoridated.

Child↗
PubMed1994

Studies on the cariostatic mechanisms of fluoride.

This paper reviews mechanisms underlying the caries-preventive effects of fluoride, with special reference to factors which govern the efficacy of topical treatments. Fluoride reduces demineralisation in several ways: by reducing bacterial acid production and acidurance; by reducing the equilibrium solubility of apatite; and by the fluoridation of apatite crystal surfaces, reducing the dissolution rate, whether or not there is reduced solubility of the bulk mineral. On available evidence, the last seems to be the most important effect. The effect depends upon the presence of sufficiently high, dissolved fluoride concentrations to maintain the surface fluoridation. The provision of dissolved fluoride is the key to successful therapy, especially topical treatments. Fluoride also promotes remineralisation even at low concentrations, thus slowing or preventing overall mineral loss. The formation of intra-oral fluoride reservoirs capable of supplying ions for a prolonged period is crucial to the success of topical treatments. Such reservoirs include calcium fluoride, formed mainly at tooth surfaces, and fluoride associated with organic components of plaque and oral soft tissues. The patterns of fluoride clearance from intraoral reservoirs are discussed. Fluoride may be present in dentifrices as the fluoride ion (F-) or as the monofluorophosphate ion (FPO3(2-)). It is concluded that the efficacy of FPO3(2-) probably depends on enzymic hydrolysis to F-. Monofluorophosphate appears to be retained less well in intra-oral fluoride reservoirs and reasons for this are discussed.

Cariostatic Agents↗
PubMed1996

Comparison of recommended and actual mean intakes of fluoride by Canadians.

The findings of two separate 1993 reports, one of the actual intake of fluoride by Canadians and the other on their recommended fluoride intake, are summarized and compared. Recent increases in very mild and mild dental fluorosis suggest that the gap between current fluoride intake and recommended intake is narrowing. The daily swallowing of fluoride dentifrice makes a large contribution to the actual total daily fluoride intake, especially in children seven months to four years of age, the age group most susceptible to fluorosis in the anterior permanent teeth. Because of the available data and methods used in each study, the reported actual and recommended fluoride intakes vary greatly both within and between age groups. It is likely that individual variation in fluoride intake also varies greatly. Comparison of the data in the two reports revealed that, for breast-fed infants and nearly all other age groups without fluoridated water, the ranges of the estimates of actual intake are lower than the recommended ranges. However, for formula-fed infants and all other age groups using fluoridated water, the estimates of actual intake greatly exceed the recommended intake, especially for the seven months to four years age group. Ingestion of fluoride at these levels during tooth development will contribute to dental fluorosis. All of the age groups have fluoride intake estimates below levels at which skeletal signs of fluoride exposure are noticed. Nevertheless, exposure to fluoride should be closely monitored and inappropriate use of discretionary fluorides curtailed.

Adolescent↗
PubMedDate not supplied

Histopathological and biochemical changes in lung tissues of rats following administration of fluoride over several generations.

The possible effects of multigenerational administration of sodium fluoride (NaF) via drinking water on lung tissue morphology and biochemistry and body and lung weight were investigated in second-generation adult male rats. For this purpose we selected 45 Albino adult Wistar rats in nine cages, each of which consisted of four females and one male. Twenty-eight pregnant rats were selected for the experiment, divided into four groups of seven rats given 1 (control group), 10, 50 and 100 mg l(-1) NaF in drinking water during the gestation period. After gestation the rats had 165 pups in total. The mothers received fluoridated water during the lactation period and the offspring of the first generation had access to fluoridated water during the suckling period (21 days) and after the weaning period (30 days) until they became mature and at the start of the second part of the experiment. During this time 23 pups died and 79 female and 63 male first-generation rats survived. These first-generation rats were then used to obtain the second-generation offspring in the same manner as before, which were subjected to the same treatments. At the end of 6 months the rats were sacrificed and autopsied. Serum fluoride levels and the activities of principal antioxidant enzymes were determined in lung tissue samples taken from all groups. In addition, the lung tissues were submitted for histopathological examination. Histological findings showed alveolar congestion, alveolar cell hyperplasia and necrosis, prominent alveolar septal vessels, epithelial desquamation and macrophages in the alveolar spaces in the experimental groups. Additionally, there were inflammatory infiltrations in peribronchial, perivascular, intraparenchymal and respiratory tract lumen; intraparenchymal hyperaemic vessels; respiratory epithelial desquamation and proliferation; intraparenchymal thick walled vessels; parenchymal fibrosis; bronchiolitis; pneumonic and focal emphysematous areas. Furthermore, the lung parenchyma was observed to have a distorted appearance with loss of alveolar architecture. These histopathological findings were more pronounced for the rat groups of 50 and 100 mg l(-1) fluoride. No significant histopathological changes were observed in the rats of the control group. The increased activities of superoxide dismutase (SOD) and reduced glutathione peroxidase (GSH-Px) and the decreased activity of catalase (CAT) in the lung tissues with 10 mg l(-1) fluoride might indicate activation of the antioxidant defence mechanism. The decrease in SOD, GSH-Px and CAT activities with 50 and 100 mg l(-1) fluoride and the increase in thiobarbituric acid-reactive substance levels might be related to oxidative damage that occurred in the lung. This multigenerational evaluation of the long-term effect of different doses of fluoride intake through drinking water on lung damage shows that the lung tissues were damaged, there was emphysema and inflammation of lung parenchyma associated with loss of alveolar architecture and the degree of lung damage seemed to correlate with the increased dosage of fluoride. A similar relationship was observed between the degree of lung damage, body and lung weight and serum fluoride levels according to the fluoride dose. Therefore, these results contribute to a better understanding of chronic fluoride toxicity in lung tissue of second-generation rats, especially via drinking water, and the biochemical findings were in agreement with histological observations. In addition, increased fluoride concentration did not affect reproduction or the number of pups dying but the body weight and lung weight ratios were affected by the high dose of fluoride in a dose-related pattern.

Animals↗
PubMed2005

Increase of enamel fluoride retention by low fluence argon laser beam: a 6-month follow-up study in vivo.

BACKGROUND AND OBJECTIVES: The aim of this 6-month in vivo study was to investigate if argon laser irradiation of enamel can increase the retention of fluoride. STUDY DESIGN/MATERIALS AND METHODS: Ninety-eight teeth in 12 patients were randomly divided into three groups: (1) EF group: 40 teeth were only treated with fluoride gel (applied for 5 minutes followed by a 1 minute rinsing with distilled water). (2) EFL group: 40 teeth were treated the same way as in the EF group but they were lased after fluoridation. (3) E group: 18 teeth were kept without any treatment as a control group. In order to quantify the fluoride content in the enamel samples, the teeth were analyzed by proton beam delivered by a tandem accelerator (PIgE, particle induced gamma-ray emission). A low energy density of argon laser beam was used: 10.74 J/cm2 (11 mm of beam diameter, irradiation time of 30 seconds, and an output power of 340 mW in continuous mode). RESULTS: The results after 6 months showed that the lased enamel still retained 52.55+/-8.47 ppm or 14.12% of fluoride after the fluoridation process, whereas the unlased enamel retained only 12.18+/-6.82 ppm or 3.27% of fluoride. The untreated and control enamel (E group: unlased and without fluoride treatment) had 1.16+/-4.27 ppm value of fluoride. The statistical test (ANOVA tests at 95% level) showed that the difference is significant between the fluoride retention in the group EFL and the group EF 6 months after fluoridation. CONCLUSIONS: The use of argon laser at low energy density (10.74 J/cm2) significantly increased the fluoride retention in lased enamel that had approximately 400 times more fluoride than the unlased enamel. We consider this procedure as an alternative clinical procedure to increase the fluoride content of enamel surface.

Acidulated Phosphate Fluoride↗
PubMed1996

The increase in spinal bone density that occurs in response to fluoride therapy for osteoporosis is not maintained after the therapy is discontinued.

In 44 osteoporotic subjects who had been treated with fluoride for 37 +/- 16 months, the fluoride was discontinued because they had shown fluoride-dependent increases in trabecular spinal bone densities from low initial levels (below the fracture threshold) to values that were equivalent to normal peak bone densities in the spines of young adults. During the subsequent period, after discontinuation of the fluoride therapy (i.e. 19 +/- 9 months), spinal bone density decreased in 73% of the subjects (i.e. 32 of 44, p < 0.03), at a rate that was comparable to the rate of the previous gain that had occurred during the treatment with fluoride (i.e. -3.23 +/- 2.39 mg/cm3 per month, compared with + 3.91 +/- 1.96 mg/cm3 per month in this, subgroup of patients, p < 0.001). Although 9 of the 44 subjects showed continuing increases in spinal bone density after discontinuation of the fluoride therapy, spinal bone density decreased in the entire group of 44 at an average rate of -1.02 +/- 4.72 mg/cm3 per month (p < 0.001, compared with the rate of the previous gain during the treatment with fluoride; i.e. +3.83 +/- 1.82 mg/cm3 per month). Surprisingly, our data showed that the rate of decrease in spinal bone density during the post-fluoride period was not affected by concurrent (undesigned) treatment with calcium, calcium plus estrogen, or calcium plus calcitriol. The cessation of fluoride therapy was also associated with a decrease in serum alkaline phosphatase activity (i.e. a decrease from the elevated levels that were observed during the period of fluoride therapy, back to the original, pre-treatment levels; p < 0.001), and that the rate of spinal bone loss after cessation of fluoride could be correlated with the prior rate of increase in serum alkaline phosphatase activity that had occurred during the treatment with fluoride (n = 44, r = 0.312, p = 0.039). Together, the observations from this retrospective analysis of data obtained from our clinical subjects suggest that fluoride-treated osteoporotic subjects who have exhibited increases in trabecular spinal bone density are at risk for bone loss after discontinuation of the fluoride therapy.

Adult↗
PubMed2005

Utility of check dams in dilution of fluoride concentration in ground water and the resultant analysis of blood serum and urine of villagers, Anantapur District, Andhra Pradesh, India.

High levels of fluoride (beyond 1.5 ppm) in ground water as source of drinking water are common in many parts of Andhra Pradesh, India, causing fluorosis. The study carried out in endemic Nalgonda District, Andhra Pradesh, has indicated that the fluoride-rich ground water present in the wells located down stream and close to the surface water bodies is getting diluted by the low-fluoride surface water. Encouraged by this result, check dams were constructed upstream of the identified marginally high fluoride bearing ground water zones in Anantapur District to reduce fluoride levels as an alternate solution for safe drinking water. In this paper, an attempt is made to study the utility and effect of these check dams in dilution of fluoride concentration in drinking water and its resultant impact on the health aspects of certain villagers of Anantapur District through the analysis of their blood serum and urine. Ground water samples from three fluoride-affected villages, blood and urine of males and females from the same villages were collected and analyzed for fluoride using ion selective electrode method. The results indicated that the fluoride levels in blood serum and urine of males in the age group of 5-11 years are found to be the highest. The concentration of fluoride in ground water is directly proportional to the concentration of fluoride in blood serum and urine. The concentration of fluoride in ground water with depth of the aquifer is a function of lithology, amount and duration of rainfall, rate of infiltration, level of ground water exploitation in the area etc. The construction of check dams upstream of the identified marginally high fluoride waters will not only cause additional recharge of ground water but also reduces the fluoride concentration eventually improving the health of the villagers.

Age Factors↗
PubMed1986

The relationship between fluoride concentrations in serum and in mineralized tissues in the rat.

By means of mini-osmotic pumps implanted into rats (110-240 g body wt), steady-state fluoride levels in serum were raised throughout a 21-day period. Small volumes of a fluoride solution twice daily by gastric intubation produced transient elevations of serum fluoride, base-line values being reached within 6 h. The calculated mean fluoride increments in serum were similar to those observed in the infused rats through the daily dosages of fluoride were about 1.0 and 0.625 mg F/kg respectively. The amounts of fluoride incorporated into periosteal bone, incisor dentine and newly-formed enamel were generally greater in the infused than intubated rats, but these differences were reduced or absent when fluoride concentrations were related to the serum-fluoride concentrations. The results from a few rats given 1.25 mg F/kg per day by continuous infusion confirmed that the amounts of fluoride incorporated into mineralized tissues were closely related to the serum-fluoride levels. Rats were also given these fluoride supplements from the 10th day of pregnancy until parturition. The mode of fluoride administration did not affect the amount of fluoride incorporated into the tissues of the mothers or into the skeletal ash of the pups when the results were expressed in relation to maternal serum-fluoride levels.

Animals↗
PubMed1994

Comparison of the effects of fluoride on the calcium pumps of cardiac and fast skeletal muscle sarcoplasmic reticulum: evidence for tissue-specific qualitative difference in calcium-induced pump conformation.

Comparison of the effects of fluoride (NaF, 1-10 mM) on the catalytic and ion transport functions of the Ca(2+)-ATPase in sarcoplasmic reticulum (SR) vesicles isolated from rabbit cardiac and fast-twitch skeletal muscles revealed similarities as well as striking tissue-specific differences depending on the experimental conditions employed. Short preincubation (3 min at 37 degrees C) of cardiac or fast muscle SR with fluoride in the absence of Ca2+ and ATP prior to initiating enzyme turnover by simultaneous addition of Ca2+ and ATP to the assay medium resulted in a strong inhibitory effect of fluoride on ATP-energized (oxalate-facilitated) Ca2+ uptake and Ca(2+)-ATPase activity. On the other hand, when turnover was initiated by the addition of ATP to SR preincubated with fluoride in the presence of Ca2+ but in the absence of ATP, fluoride caused concentration-dependent stimulation of active Ca2+ uptake by fast muscle SR with no appreciable change in Ca(2+)-dependent phosphoenzyme (EP) formation (from ATP) or Ca(2+)-ATPase activity but inhibition of active Ca2+ uptake by cardiac SR with concomitant inhibition of EP formation and Ca(2+)-ATPase activity. Exposure of cardiac or fast muscle SR to fluoride in the presence of both Ca2+ and ATP resulted in concentration-dependent stimulatory effect of fluoride on Ca2+ uptake with no change in EP formation or Ca(2+)-ATPase activity, this effect diminished substantially at saturating oxalate concentration in the assay. Assessment of the effects of deferoxamine (1 mM) and exogenous aluminum (10 microM) did not indicate a requirement for aluminum in the inhibitory or stimulatory effect of fluoride. These results suggest that (a) the Ca2+ and ATP-deprived (E1/E2) but not the Ca2+ plus ATP-liganded (CaE1ATP) conformation of the SR Ca(2+)-ATPase is susceptible to inhibition by fluoride in both cardiac and fast muscle; (b) the Ca(2+)-bound conformation (CaE1) of the SR Ca(2+)-ATPase is susceptible to inhibition in cardiac muscle but is refractory to fluoride in fast muscle; and (c) the stimulatory effect of fluoride is largely secondary to its ability to mimic the action of oxalate in intravesicular Ca2+ trapping when the fluoride-resistant enzyme is turning over normally. Fluoride inhibited phosphorylation of the Ca(2+)-free enzyme by Pi in cardiac and fast muscle SR indicating that fluoride sensitivity of the phosphorylation site of the SR Ca(2+)-ATPase is similar in cardiac and fast muscle.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗
PubMed2005

Estimation of fluoride distribution in the mandible and teeth of the red deer (Cervus elaphus L.) from industrially polluted areas in Poland.

MINI SUMMARY: Animals from areas contaminated by industrial emissions containing fluoride may accumulate it predominantly in hard tissues. Therefore, an analysis was performed for the determination of fluoride content in mandibles and teeth of deer living at large in different areas in Western Pomerania (Poland). Samples of hard tissues obtained with a dental drill, were dissolved in perchloric acid and analyzed for fluoride content with an ion-selective electrode. Using the Generalized Regression Neural Network (GRNN), it was possible to arrange definite variables according to their order of importance concerning the fluoride mean content in investigated bone material. Parametric analysis revealed in which sites of mandibles and teeth the fluoride accumulation was the highest. In our calculation, the traditional statistic as well as artificial neural network was applied. OBJECTIVE: One of the interesting properties of fluoride is its balancing accumulation in the hard and soft tissues. In this paper, we decided estimate how the changeable doses of fluoride in natural environment influence on fluoride distribution and accumulation in the examined sites of mandible and teeth. MATERIAL AND METHOD: The material consist of 103 mandibles of red deer (Cervus elaphus L.) from five forestry districts of Western Pomerania in Poland, which are located near or far away from two major industrial plants: Police Chemical Work and the Dolna Odra Coal Power Plant. Samples (10 mg of powdered bone or tooth) were dissolved in perchloric acid and the fluoride content was determined with an ion-selective electrode. Comparisons were done with the Statistica 5.5 and Statistica Neural Networks. RESULTS: Animals living in Western Pomerania (Poland) have high fluoride contents in their bones. Fluoride accumulation in mandibles and teeth is irregular. The higher content of fluoride show incisal area, but coronoid process of the mandible was not sensitive to different exposure of environmental fluoride at all. Parametric analysis revealed that the accumulation pattern of fluorine was different in the two groups of deer. CONCLUSIONS: Many biological and environmental factors may influence on incessant fluoride accumulation in osseous tissue of ruminants living at large. The use of artificial neural networks enables a more accurate insight into the process of fluorine accumulation in the mandible and teeth and helps in the ranking of factors influencing this process.

Animals↗
PubMed2006

Screening high-fluoride and high-arsenic drinking waters and surveying endemic fluorosis and arsenism in Shaanxi province in western China.

The objectives of this study were to screen high-fluoride and high-arsenic drinking waters, to evaluate the effectiveness of fluoride-reducing projects and to assess the present condition of endemic fluorosis and arsenism in Shaanxi province in western China. For screening high-fluoride drinking waters, five water samples were collected from each selected village where dental fluorosis patients were detected in 8-12 year-old children. For evaluating the effectiveness of fluoride-reducing projects, four water samples were collected from each project at end-user level. Fluoride concentrations in water samples were measured by fluoride-selective electrode method or spectrophotometry. Dental fluorosis in children aging 8-12 years was examined according to Horowitz's Tooth Surface Index of Fluorosis. Skeletal fluorosis in adults was detected clinically and radiologically according to Chinese Criteria of Clinical Diagnosis of Skeletal Fluorosis. For screening high-arsenic waters, 20 water samples were collected from each village which was selected from areas characterized by the geographic features to induce high-arsenic underground water, i.e., alluvial plains, ore mining or smelting areas, geothermal artesians, and thermal springs. Arsenic concentrations in water samples were determined by spectrophotometry or arsine generation atomic fluorospectrophotometry. Arsenism in adults aging 40-89 years was examined in villages with arsenic concentrations in drinking water above 0.05 mg/l according to Chinese Criteria for Classification of Endemic Arsenism Areas and Clinical Diagnoses of Endemic Arsenism. The results showed that the fluoride level of 7144 water samples was 1.17 +/- 0.93 mg/l. There were 3396 (47.6%) high-fluoride waters (fluoride level was above 1.0 mg/l) distributing in 786 (45.1%) villages, where about 0.8 million (50.0%) people inhabited. Additionally, the 1315 fluoride-reducing projects were studied. The fluoride level of the projects was 2.79 +/- 1.09 and 0.98 +/- 0.47 mg/l before and after building the projects, which remained at relatively lower level (1.03 +/- 0.47 mg/l). But there were still 58.0% of the projects providing drinking waters with fluoride concentrations beyond 1.0mg/l. The rates of dental fluorosis and skeletal fluorosis were 38.2% and 11.8%, respectively. The arsenic level of 1732 water samples was 0.010 +/- 0.082 mg/l. There were 174 (14.9%) high-arsenic waters (arsenic level was above 0.010 mg/l) being detected, distributing in 41 (38.7%) villages. The arsenic level in 53 (4.5%) water samples was beyond 0.025 mg/l. There were 3 villages with arsenic level in drinking water beyond Chinese National Permissible Limits (0.050 mg/l), and the prevalence rate of arsenism reached 37.0% in these three villages, 3.7%, 22.2%, and 11.1% of subjects suffering from mild, moderate, and severe arsenism, respectively. Conclusively, the wide distribution of high-fluoride drinking waters contributes to the prevalence of dental and skeletal fluorosis in Shaanxi province and the quality of fluoride-reducing projects should be further improved. Ore mining and smelting induces high-arsenic drinking waters, resulting in arsenism prevalence in Shang-luo city. Proper measures should be taken to deal with water pollution in the ore mining and smelting areas in order to solve the high-arsenic water problem in Shaanxi province.

Adult↗
PubMed2003

Fluoride toxicity to aquatic organisms: a review.

Published data on the toxicity of fluoride (F-) to algae, aquatic plants, invertebrates and fishes are reviewed. Aquatic organisms living in soft waters may be more adversely affected by fluoride pollution than those living in hard or seawaters because the bioavailability of fluoride ions is reduced with increasing water hardness. Fluoride can either inhibit or enhance the population growth of algae, depending upon fluoride concentration, exposure time and algal species. Aquatic plants seem to be effective in removing fluoride from contaminated water under laboratory and field conditions. In aquatic animals, fluoride tends to be accumulated in the exoskeleton of invertebrates and in the bone tissue of fishes. The toxic action of fluoride resides in the fact that fluoride ions act as enzymatic poisons, inhibiting enzyme activity and, ultimately, interrupting metabolic processes such as glycolysis and synthesis of proteins. Fluoride toxicity to aquatic invertebrates and fishes increases with increasing fluoride concentration, exposure time and water temperature, and decreases with increasing intraspecific body size and water content of calcium and chloride. Freshwater invertebrates and fishes, especially net-spinning caddisfly larvae and upstream-migrating adult salmons, appear to be more sensitive to fluoride toxicity than estuarine and marine animals. Because, in soft waters with low ionic content, a fluoride concentration as low as 0.5 mg F-/l can adversely affect invertebrates and fishes, safe levels below this fluoride/l concentration are recommended in order to protect freshwater animals from fluoride pollution.

Animals↗