Acute Fluoride Toxicity from Ingesting Home-use Dental Products in Children, Birth to 6 Years of Age

Objectives : This paper analyzes reports to the American Association of Poison Control Centers (AAPCC) of suspected overingestion of fluoride by children younger than 6 years of age between 1989 and 1994, and estimates the probably toxic amounts of various home-use fluoride products in children younger than 6 years of age. Methods : Annual incidence rates of reported fluoride exposures attributed to dietary supplements, toothpaste, and rinses were calculated. Probably toxic amounts of each product were calculated using the frequently cited dose of 5 mg/kg. Results : Children younger than 6 years of age accounted for more than 80 percent of reports of suspected overingestion. While the outcomes were generally not serious, several hundred children were treated at health care facilities each year. A 10 kg child who ingests 50 mg fluoride (10.1 g 1.1% NaF gel; 32.7 g 0.63% SnF₂ gel; 33.3 g 1,500 ppm F toothpaste; 50 g 1,000 ppm F toothpaste; and 221 mL 0.05% NaF rinse) will have ingested a probably toxic dose. Conclusion : Overingestion of fluoride products in the home is preventable. Dentists and other health care providers should educate parents and child care providers about the importance of keeping fluoride products out of reach of children. Manufacturers should be encouraged by the ADA and the FDA to use child-resistant packaging for all fluoride products intended for use in the home.     

Review of the Anticaries Effectiveness of Professionally Applied and Self -applied Topical Fluoride Gels

Of the five types of topical fluoride gel products available in the United States, two have not been clinically tested in randomized double blind clinical trials. For those tested, the averaged results of clinical trials involving schoolchildren in fluoride-deficient communities indicate a caries reduction of approximately 26 percent from either a professional or self-administered program. A similar relative reduction can be expected from programs conducted in fluoridated communities, but the absolute caries inhibition is less. Twice-a-year professional applications are more effective than once-a-year applications, and self-applications using trays are more effective than applying the gel on a toothbrush. For subjects beyond school age, there are few clinical studies of either self-applied or professionally applied gels; however, current epidemiological evidence does not indicate a need for public health caries preventive programs for healthy employed adults. For medically compromised patients, especially those exhibiting rampant caries associated with radiation-induced xerostomia, a variety of topical gel procedures appear to be effective in limiting caries.     

Estimation of the fraction of an ingested dose of fluoride excreted through urine in pre-school children

OBJECTIVE: To determine the fraction of an ingested fluoride dose of 1 mg in 50 mL orange juice that is excreted through the urine (FUEF) of children aged 3-5 years. METHODS: Eighty-eight controlled determinations involving 24-hour urinary collections from a total of 48 children were carried out during consecutive control and test days. Net fluoride urinary excretion due to the ingested dose was calculated as the difference between the total amount of fluoride excreted by each child on test and control days. RESULTS: Excretion of the fluoride ingested from the single fluoride dose presented an average value of 30.7% (95% CI: 28.9-32.5%). No significant associations were found between individual FUEF values with either anthropometrical variables or urinary pH values. The average FUEF value found in the present study lies between previously reported values for infants and young adults. The epidemiological usefulness of the FUEF values in estimating daily fluoride dose in pre-school children is discussed.     

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本文主要对专业人员使用的局部用氟措施的适应证、应用方法和频率、临床效果进行回顾。专业人员使用的局部用氟措施通常在口腔临床和社区口腔健康项目中应用,其主要适用于高龋危险性的儿童、青少年和成年人。应用频率取决于个体对龋的敏感性,一般推荐每半年应用1次。氟化凝胶、泡沫和含氟涂料都能有效预防儿童乳、恒牙龋的发生,但对6岁以下儿童不推荐使用氟化凝胶。另外高浓度含氟涂料还具有明显抗牙本质敏感的作用。     

Patterns of fluoride intake from birth to 36 months

OBJECTIVES: Dental fluorosis prevalence has increased in the United States, Canada, and other nations due to the widespread availability of fluoride in many forms, with fluoride ingestion during the first three years of life appearing most critical in fluorosis etiology. With few contemporary studies of fluoride ingestion in this age group, the purpose of this paper is to describe patterns of estimated fluoride ingestion from birth to 36 months of age from water, dentifrice, and dietary fluoride supplements and combined. METHODS: Repeated responses to separate series of questions about water intake, use of fluoride dentifrice, and use of fluoride supplements were collected by questionnaire as part of the longitudinal Iowa Fluoride Study and used to estimate fluoride intake. Estimated intake is reported by source and combined at different ages. Effects of subject age and other covariates on fluoride intake were assessed using regression methods appropriate for the analysis of correlated data. RESULTS: For most children, water fluoride intake was the predominant source, especially through age 12 months. Combined daily fluoride intake increased through 9 months, was lower at 12 and 16 months, and increased again thereafter. Mean intake per unit body weight (bw) was about 0.075 mg F/kg bw through 3 months of age, 0.06 mg F/kg bw at 6 and 9 months, 0.035 mg F/kg bw at 12 and 16 months, and 0.043 mg F/kg bw from 20-36 months. Depending on the threshold chosen (e.g., 0.05 or 0.07 mg F/kg bw), variable percentages of the children exceeded the levels, with percentages greatest during the first 9 months. Regression analyses showed fluoride intake (mg F/kg bw) from 1.5-9 months to decrease with increasing child's age, mother's age, and mother's education, with a complex three-way interaction among these factors. From 12-20 months, fluoride intake increased with increasing child age and decreased with increasing mother's age. No statistically significant relationships were found for fluoride intake from 24-36 months. CONCLUSIONS: There is considerable variation in fluoride intake across ages and among individuals. Longitudinal studies may be necessary to fully understand the relationships between fluoride ingestion over time and development of fluorosis.     

儿童使用APF凝胶和氟化泡沫氟的作用量及摄入量比较

目的检测中国儿童氟化泡沫使用量、滞留量并与含氟凝胶比较。方法研究对象为成都市、小学1年级学生（年龄6～7岁）105人，55人使用氟化泡沫、50人使用含氟凝胶。将含氟凝胶或泡沫放置在已称重的托盘后再称总重，按常规操作程序应用于实验对象。使用后收集唾液、托盘及盘中剩余药物。取出托盘2min及10min后，用事前称重塑料试管继续收集唾液2min。实验室检测采用盲法，使用氟离子电极检测样本氟浓度并计算回收的总氟量。结果6～7岁儿童平均使用0．52±0．10g的氟化泡沫和2．61±0．43g含氟凝胶。滞留的氟量氟化泡沫为1．76±0．72mg，含氟凝胶为6．75±4．56mg。氟化泡沫的用量为含氟凝胶重量的19．92％，吸收量为含氟凝胶的26．07％。结论　氟化泡沫有明显减少病人氟使用量的优点。     

饮料茶氟含量研究

本研究用氟离子选择电极、微量扩散、高温气化分离、气相色谱方法分别测定日本东京市售 30种罐装饮料茶 ,其结果 :红茶饮料是 1.0 2 ug/ml、乌龙茶是 0 .91ug/ml、杜仲茶是 0 .0 2 9ug/ml、绿茶是0 .6 9ug/ml、大麦茶饮料茶是 0 .0 0 5ug/ml。氟离子选择电极方法能在多种离子共存的条件下对氟离子特异反应 ,该方法广泛应用于牙科领域、气相色谱、微量扩散、高温气化分离方法也能够测定氟     

Urinary fluoride excretion by preschool children in six European countries

Abstract -  Objective: To measure and compare 24-h urinary fluoride excretion in children aged 1.5-3.5 years from European study sites and to use these data to estimate the 24-h fluoride intake. Method: Twenty-four-hour urine samples were collected from 3-year-old children ( n  = 86) who were already participating in a European multicentre study. Samples were collected from Cork, Ireland ( n  = 19) where the water is fluoridated to a concentration between 0.8 and 1.0 ppm and from five sites with a water fluoride concentration <0.15 ppm: Knowsley, England ( n  = 18); Oulu, Finland ( n  = 18); Reykjavik, Iceland ( n  = 4); Haarlem, the Netherlands ( n  = 6); Almada/Setubal, Portugal ( n  = 21). The volume of the samples was measured; they were analysed for fluoride concentration and the 24-h urinary fluoride excretion was calculated. From this an estimate of the daily fluoride intake was made. Results: It was found that the mean fluoride excretion in response to the usual conditions of fluoride intake in the children in the nonfluoridated areas ranged from 0.16 mg (±0.08) in Oulu to 0.33 mg (±0.27) in Almada/Setubal with an overall mean of 0.23 mg (±0.19). The mean 24-h fluoride excretion in fluoridated Cork was 0.37 mg (±0.11). There was a significant difference between the fluoride excretion in the nonfluoridated areas and that in the fluoridated areas, and the data were broadly in agreement with WHO standards. Conclusions: The daily urinary fluoride excretion and estimated fluoride intake in these children appeared to be within acceptable limits.     

Fluoride supplements: current effectiveness, side effects, and recommendations

Abstract – A critical review of the literature was conducted to determine the current effectiveness of fluoride supplements in caries prevention and their role as risk factors for dental fluorosis. Use of fluoride supplements by young children is idiosyncratic and all of the studies which investigated the effectiveness of this regimen suffered from a significant drop in the number of participants receiving daily supplements. The scientific evidence supports the efficacy of fluoride supplements in caries prevention but there is weaker support for their effectiveness. Fluoride supplements are a risk factor for dental fluorosis. though their contribution to the increase in fluorosis prevalence is less than that of water fluoridation and fluoridated dentifrices because of their more limited and shorter use. There is also evidence that fluoride supplements are used inappropriately in fluoridated areas. The availability of optimal levels of fluorides in beverages in non-fluoridated communities raises the question of whether fluoride supplements are needed in the 1990_s, and whether it is time to consider the total fluoride intake not only from water but also from foods, beverages, and dentifrices, when recommending supplements. A re-evaluation of the need for and dosage schedules of fluoride supplements is warranted.     

Overview of the history and current status of fluoride supplementation schedules

Clinical trials of dietary fluoride supplements began in the 1940s in an effort to bring the benefits of fluoride to those who did not receive it through their drinking water. Following the early success of these trials, the Council on Dental Therapeutics of the American Dental Association (ADA) published its first recommendations for fluoride supplementation in 1958. The American Academy of Pediatrics (AAP) followed with its own recommendations in 1972. During the 1970s a variety of alternative schedules appeared in the literature, most in reaction to the findings of unexpectedly high levels of enamel fluorosis in children being supplemented with the AAP schedule. In 1979 the ADA and AAP agreed on essentially identical schedules. During the 1980s, however, the prevalence of enamel fluorosis continued to increase, and fluoride supplements were found in some studies to be a risk factor for fluorosis. This finding prompted another round of dosage schedule recommendations in the early 1990s. This paper presents a history of fluoride dosage recommendations and reviews the recent proposals for reducing supplement dosage.     

Is the fluoride/creatinine ratio of a spot urine sample indicative of 24‐h urinary fluoride?

OBJECTIVE: The main aim of this study was to determine how representative the fluoride/creatinine (F/Cr) ratio of a spot urinary sample is of the fluoride content of a 24-h urine sample in young children aged 12-36 months. Subsidiary objectives were to: (a) evaluate the use of 24-h urine samples in monitoring fluoride exposure and (b) estimate the retention of fluoride in very young children. METHODS: Seven healthy children residing in a fluoridated area completed the study. Dietary information was obtained using a 3-day estimated food diary followed by an interview on the fourth day. Samples of foods and drinks were analysed for fluoride content. Ingestion of fluoride from toothpaste was also measured. A 24-h urine sample and a morning spot urine sample were collected from each child. RESULTS: The mean age of the children was 32 months (range: 16-36 months). The mean total daily intake of fluoride was 0.71 (+/-0.41) mg or 0.05 (+/-0.02) mg/kg bodyweight, of which 37% came from the diet, the remainder being from toothpaste ingestion. None of the children used any other sources of fluoride such as fluoride tablets or fluoridated salt. The mean F/Cr ratio was 1.49 (+/-0.63) mg F/g creatinine. A positive correlation (Pearson's correlation=0.76, P=0.05) between fluoride excretion estimated using the F/Cr ratio in a morning spot urine sample and fluoride excretion in a 24-h urine sample was found. There was also a positive correlation (Pearson's correlation=0.83, P=0.02) between total daily fluoride intake and 24-h urinary fluoride excretion. Less than half (43%) of the total daily fluoride intake was retained in the body. CONCLUSIONS: The F/Cr ratio of a morning spot urine sample may be used to estimate mean 24-h urinary excretion of fluoride and therefore has potential application for larger-scale epidemiological studies where 24-h samples are impractical. Estimates of 24-h urinary fluoride excretion can be used to gauge fluoride exposure.     

Total fluoride intake in children aged 22-35 months in four Colombian cities

OBJECTIVE: To obtain information on the level of total fluoride intake from food, beverages and toothpaste by children at the age of 22-25 months of low and high socioeconomic status (SES) in major Colombian cities. METHODS: Daily fluoride intake was assessed by the duplicate plate method and by recovered toothpaste solution during a 3-day period and afterwards analysed by the microdiffusion method. RESULTS: Mean daily fluoride intake was 0.11 (+/-0.10), 0.14 (+/-0.12), 0.10 (+/-0.07) and 0.07 (+/-0.06) mg/kg body weight (bw)/day in Bogota, Medellin, Manizales and Cartagena, respectively. The total fluoride intake was higher in low-SES subjects in the cities of Medellin and Bogota. In the high-SES children of the four cities, the average intakes ranged from 0.06 to 0.09 mg F/kg bw, whereas, the low-SES children in three cities had intakes between 0.11 and 0.21 mg F/kg bw (Cartagena, 0.07). Toothpaste (containing 1000-1500 ppm F, with 1500 ppm F being more common) accounted for approximately 70% of total fluoride intake, followed by food (24%) and beverages (<6%). More than half the children had their teeth brushed by an adult, on average twice a day, using 0.22-0.65 g of toothpaste. CONCLUSION: Children from three Colombian cities have a mean total daily fluoride intake above the 'optimal range'. Health authorities should promote an appropriate use of fluoridated dentifrices discouraging the use of dentifrices containing 1500 ppm F in children younger than 6 years of age and promoting a campaign of education of parents and oral health professionals on adequate toothbrushing practices.     

Fluoride release from NaF‐ and AmF‐impregnated toothpicks and dental flosses in vitro and in vivo

The aim of this study was to determine the fluoride release from toothpicks and dental flosses in vitro and in vivo, and to evaluate various approximal administration methods. In vitro, a total of 23 commercially available toothpicks and dental flosses and 3 prototypes impregnated with sodium fluoride (NaF), amine fluoride (AmF), or a combination of these two were tested. Fluoride release was determined for up to 24 h using an ion‐specific electrode. A large variation was found between the products; most fluoride being released after 30 min. Generally speaking, toothpicks produced higher values than flosses. In vivo, the fluoride concentration in both treated and non‐treated approximal areas was evaluated after using 2 different types of toothpicks and 4 dental flosses and after different application methods—such as a fluoride gel and fluoride solution. The mean fluoride concentration in oral fluid was up to 10 times higher at the treated sites than at the non‐treated sites. Use of a fresh toothpick or a fresh piece of dental floss in each approximal space resulted in higher values compared with using one and the same toothpick/floss for the whole dentition. An interdental brush dipped in 0.2% NaF gel and a mouthrinse with 0.2% NaF resulted in elevated fluoride concentrations at the same level as when multiple toothpicks were used. To conclude, there are large variations in the fluoride release from various brands of fluoridated toothpicks and dental flosses. Treatment with a fluoridated toothpick or a dental floss can be expected to give elevated fluoride concentrations in the approximal area up to 60 min. Another interesting method for administering fluoride in the approximal area is to use an interdental brush dipped in fluoride gel.     

Fluoride uptake and resistance to further demineralisation of demineralised enamel after application of differently concentrated acidulated sodium fluoride gels

The objective of this study was to analyse fluoride uptake and microhardness alteration of carious-like demineralised enamel after application of differently concentrated acidulated sodium fluoride gels and to determine the effect of fluoridation on enamel resistance against subsequent demineralisation. Artificial caries-like lesions of bovine enamel specimens were treated with sodium fluoride gels of different concentration (group A: 1.25%, group B: 0.62%, group C: 0.31%, group D: 0.15%; n=20 each group) for 5 min and stored in artificial saliva for 24 h. This cycle was carried out three times. Subsequently, KOH-soluble and structurally bound fluoride (determined at depths of 30, 60, and 90 m) were analysed. In the second part of the study, for each 12 enamel specimens surface microhardness was determined before and after demineralisation, after fluoridation with the differently concentrated gels A–D, and after a second demineralisation. With all groups uptake of KOH-soluble and structurally bound fluoride resulted in higher levels than baseline content. Statistical analysis revealed significant differences between fluoride uptake among the groups, with highest uptake for the 1.25% gel and lowest for the 0.15% gel. Moreover, with all gels highest uptake was observed in the outermost enamel layer (P<0.05). Microhardness values after second demineralisation increased with increased concentration of the applied sodium fluoride gel. Increasing concentration of the applied gel implies better protection of the enamel specimens against subsequent demineralisation (P<0.05). It is concluded that differently concentrated acidulated sodium fluoride gels resulted in concentration-related significant uptake of fluoride in carious-like demineralised enamel, leading to a better demineralisation protection with increasing fluoride concentration in the gel.     

选择性微电极测定唾液中氟离子的初步探讨

目的 :研制氟离子选择性微电极 (F -ISME)并探讨其在口腔领域应用的可行性。方法 :采用氟化镧电极晶体 (LaF3:EU :Ca)为敏感膜制备F -ISME ,并进行各项性能测试 ,结合氟离子选择性电极 (F -ISE)对成人唾液样本的氟离子进行检测和对比分析。结果 :F -ISME的检测下限为 2 .5× 10 -6 mol/L ,试样的加标回收率平均为 95 .5 % ,线性范围、重现性、稳定性、响应时间、pH范围等各项性能良好 ,对唾液中氟离子的测定与F -ISE基本一致。结论 :F -ISME具有简便、快速、敏感、准确的性能 ,在口腔研究领域有较好的应用前景     

Enamel mineralization disturbances in 12-year-old children with known early exposure to fluorides

Abstract Enamel changes and caries experience were studied in 134 12-year-old children with a known early exposure to fluoride tablets and/or fluoride containing toothpaste. The influence of birth weight and breast-feeding period was also analyzed. A clinical intact enamel was found in 32% of the children. Enamel fluorosis was found in 45% and localized opacities or hypoplasias in 40% Children who had consumed fluoride tablets for a period of at least 12 months from the age of 6 months ran a 5.4 times greater risk of developing enamel fluorosis than children with no such consumption. No such risk could be shown in children who at 6 or 12 months of age started to use fluoride toothpaste. There was no statistically significant reduction in the prevalence of smooth surface caries or fillings in children with an exposure to fluoride tablets.     

Review on fluoride, with special emphasis on calcium fluoride mechanisms in caries prevention

Low concentrations of fluoride have a beneficial effect on enamel and dentin de- and remineralization. After fluoride treatments, such as topical applications, rinses or dentifrices, salivary fluoride concentrations decrease exponentially in a biphasic manner to very low concentrations within a few hours. For treatments to be effective over periods longer than the brushing and the following salivary clearance, fluoride needs to be deposited and slowly released. Calcium fluoride (or like) deposits act in such a way. owing to a surface covering of phosphate and/or proteins, which makes the CaF₂ Jess soluble under in vivo conditions than in a pure form in inorganic solutions. Moreover, due to the phosphate groups on the surface of the calcium fluoride globules, fluoride is assumed to be released with decreasing pH when the phosphate groups are protonated in the dental plaque.