Factors affecting the ingestion of fluoride dentifrice by children

Doses of fluoride toothpaste for children up to 24 months

AIM

The aim of this study was to test the dose of fluoride toothpaste by parents for their children aged up to 24 months.

METHODS

Parents who use fluoride toothpastes for their children were asked to dose two commercially available toothpastes (A and B) with 1000 ppm fluoride each for their children as they would normally do at home. The toothpaste amounts were weighed, and as reference, the weight of an 'optimal' grain of rice-size amount of each toothpaste was used.

RESULTS

61 parents dosed a mean of 0.263 ± 0.172 g toothpaste A and 0.281 ± 0.145 g toothpaste B. The parents' mean doses were 5.9 times higher for toothpaste A and 7.2 times higher for toothpaste B than an 'optimal' grain of rice-size amount (the reference dose as recommended). The difference between parent's and reference dose was statistically significant (p < 0.001). Moreover, 39.3% of parents were not aware about conditions of use and warnings that have to be printed on the package of fluoride toothpastes.

CONCLUSION

In this study, parents significantly overdosed the toothpaste for their children. To avoid fluoride intake from toothpaste, parents can choose fluoride-free alternatives for the oral care of their infants and toddlers.

Effect of Commercial Children's Mouthrinses and Toothpastes on the Viability of Neonatal Human Melanocytes: An In Vitro Study

In this study, we examined the cytotoxic effects of six commercial children's mouthrinses (designated as #1, #2, #3, #4, #5, and #6) and four commercial children's toothpastes (designated as #1, #2, #3, and #4) on primary human neonatal melanocytes that were used as a representative model for oral melanocytes. Mouthrinses diluted directly with culture medium (1:2, 1:5, 1:10, 1:100, and 1:1000) were added to monolayers of melanocytes for 2 min, followed by 24 h recovery, after which MTS cytotoxicity assay was conducted. The extracts of each toothpaste were prepared (50% w/v), diluted in culture medium (1:2, 1:5, 1:10, 1:50, 1:100, and 1:1000), and added to cell monolayers for 2 min (standard brushing time), followed by an analysis of cell viability after 24 h. Results showed that all mouthrinses except mouthrinse #4 showed significantly greater loss of cell viability, ascribed to cetylpyridinium chloride (CPC) that induced significant cytotoxicity to melanocytes (IC50 = 54.33 µM). In the case of toothpastes, the examination of cellular morphology showed that a 2 min exposure to all toothpaste extracts induced a concentration-dependent decline in cell viability, pronounced in toothpaste containing sodium lauryl sulfate (SLS) detergent. Further results suggested SLS to be the critical driver of cytotoxicity (IC50 = 317.73 µM). It is noteworthy that toothpaste #1 exhibited much lower levels of cytotoxicity compared to the other three toothpastes containing SLS. Taken together, these findings suggest that the melanocytotoxicity of children's mouthrinse (#4) and toothpaste (#1) is comparatively low. To the best of our knowledge, this is the first study to examine the impact of children's toothpastes and mouthrinses on neonatal primary human melanocytes. Future studies to investigate these findings in a realistic scenario replicating oral cavity conditions of the presence of microbiota, pellicle layer and saliva, and other cell types are warranted.

Teeth: Small but Mighty and Mighty Important. A Comprehensive Review of Children's Dental Health for Primary Care Clinicians

Healthy teeth allow us to eat and stay well-nourished. Although primary care clinicians receive limited training about teeth, given the common nature of dental problems, it is important that they understand and recognize normal and abnormal dental conditions and can implement primary and secondary prevention of dental conditions in their practice. PubMed has been used to search the scientific literature for evidence on the following topics: normal dental development, dental abnormalities, malocclusion, teething, dental caries and related epidemiology and prevention, fluoride, dental injury and its management and prevention; and identification, prevention and treatment of gingivitis and periodontal disease. Literature review relied on randomized controlled trials, meta-analyses, systematic reviews, and Cochrane reviews when relevant and available. Other sources of evidence included cohort and case-control studies. Consensus statements and expert opinion were used when there was a paucity of high-quality research studies. The literature has been synthesized on these topics to make them relevant to pediatric primary care clinicians, and as available, the strength of evidence has been characterized when making clinical recommendations.

Fluoride Exposure in Early Life as the Possible Root Cause of Disease In Later Life

Fluoride, one of the most celebrated ingredients for the prevention of dental caries in the 20th century, has also been controversial for its use in dentifrices and other applications. In the current review, we have concentrated primarily on early-life exposure to fluoride and how it may affect the various organs. The most recent controversial aspects of fluoride are related to toxicity of the developing brain and how it may possibly result in the decrease of intelligence quotient (IQ), autism, and calcification of the pineal gland. In addition, it has been reported to have possible effects on bone and thyroid glands. If nutritional stress is applied during a critical period of growth and development, the organ(s) and/or body will never recover once they pass through the critical period. For example, if animals are force-fed during experiments, they will simply get fat but never reach the normal size. Although early-life fluoride exposure causing fluorosis is well reported in the literature, the dental profession considers it primarily as an esthetic rather than a serious systemic problem. In the current review, we wanted to raise the possibility of future disease as a result of early-life exposure to fluoride. It is not currently known how fluoride will become a cause of future disease. Studies of other nutritional factors have shown that the effects of early nutritional stress are a cause of disease in later life.

Highly acidic pH values of carbonated sweet drinks, fruit juices, mineral waters and unregulated fluoride levels in oral care products and drinks in India: a public health concern

PURPOSE

The objective of this study was to quantify and assess the concentrations of fluoride in commonly used oral care products, fruit juices, bottled waters, soft drinks, favoured bottled milk and milkshakes and to determine the pH of carbonated sweet drinks and drinks marketed in India.

MATERIALS AND METHODS

Various commercial brands of dentifrices, toothpowders, mouthwashes, bottled waters, sweet carbonated drinks and fruit juices were collected randomly from different outlets in Mangalore city, Karnataka, India. A fluoride ion-selective electrode was employed to estimate the fluoride concentrations. A standardised pH meter was used to detect pH in the drinks.

RESULTS

The fluoride level in toothpastes ranged between 96 and 1397 mg/l, whereas in toothpowder the fluoride content ranged from 35 to 1380 mg/l and mouthwash fluoride concentrations varied from 6 to 228 mg/l. The fluoride level in bottled waters ranged between 0.10 and 0.12 mg/l, and that in fruit juices between 0.09 and 0.21 mg/l. Most of the carbonated sweet drinks and fruit juices had highly acidic pH values which ranged between 2.62 and 4.26.

CONCLUSION

Of the wide variety of dentifrices and toothpowders available in India, most brands do not indicate the fluoride levels on their packaging or inserts. Similarly, the unregulated acidic pH values of carbonated sweet drinks are not only potentially contributing to non-carious tooth loss (enamel erosion and dentine erosion), but are also a contributing factor to the weight gain observed in Indian adolescents.

Dentifrices for children differentially affect cell viability in vitro

Objectives

Child dentifrices vary in their composition, with possible differential impacts on cells in the oral soft tissue. While cytotoxicity studies have been performed on adult dentifrices, no respective studies have thus far been reported on child dentifrices.

Material and methods

Seventeen commercial dentifrices for children up to 12 years of age were evaluated with respect to their in vitro cytotoxicity on gingival fibroblasts, oral squamous cell carcinoma HSC-2 cells, and L929 mouse fibroblasts. Proliferation was analyzed and live-dead staining was performed.

Results

Ten child dentifrices greatly reduced cell viability with LC50 values below 5 %. Four dentifrices showed a moderate cytotoxicity with LC50 values between 5 and 20 %. Three child dentifrices showed almost no cytotoxicity with LC50 values above 95 %. The results of the assays for proliferation and live-dead staining supported these findings.

Conclusions

The different composition of the child dentifrices translated into a broad spectrum of in vitro cytotoxicity on cells of the oral cavity.

Clinical relevance

The in vitro data provide the scientific foundation for further in vivo research testing the clinical relevance of the present findings.

A randomized clinical study to assess ingestion of dentifrice by children

This study investigated whether there was a difference in amounts of dentifrice ingested by children based on age using pea-sized instructions. The study had a randomized, single-blinded, 3-period, crossover design modelled after Barnhart et al. (1974) with one regular-flavored and two specially-flavored dentifrices used ad libitum. Subjects were enrolled in three groups: 2-4, 5-7, and 8-12 years. They were instructed to brush at home as they would normally with each dentifrice for 3 weeks (9 weeks total). On weekly study-site visits, subjects brushed with the assigned dentifrice containing a lithium marker to measure the amount of dentifrice ingested and used. Averaging across dentifrices, amounts ingested were: 0.205 g (2-4 yr), 0.125 g (5-7 yr) and 0.135 g (8-12 yr), demonstrating 2-4 year-olds ingested significantly more than older children (p ≤ 0.002). Averaging across dentifrices, amounts used were: 0.524 g (2-4 yr), 0.741 g (5-7 yr) and 0.978 g (8-12 yr) suggesting an age-related effect (p < 0.01). Findings also showed that ingestion amount for specially-flavored dentifrices may increase relative to regular-flavored dentifrice for children 2-7 years-old. This research demonstrated that dentifrice ingestion amount decreased significantly with age while usage amount increased with age. Importantly, ingestion and usage levels in younger children reflect "pea-sized" direction and were numerically lower than historical levels reported prior to this direction.

Dental fluorosis associated with chronic ingestion of dentifrices – what health professionals should know

This paper reports on two cases of dental fluorosis caused by inadvertent ingestion of fluoridated dentifrice. An eight-year-old child showed whitish spots and loss of dental enamel in first permanent molars and whitish spots without structure loss in permanent incisors and primary second molars, whereas a fourteen-year-old teenager showed whitish spots in all permanent teeth. In both cases, homologue teeth were affected similarly and mothers did not report on the use of fluoride supplements during pregnancy or children’s infancy. The water fluoridation of the city where they live is considered optimal. Both patients reported eating dentifrice frequently during tooth brushing and in other occasions. Mothers also stated that they did not receive instructions about oral hygiene or about the fact that chronic ingestion of dentifrice could contribute to the development of dental fluorosis. It is believed that the cooperative work between dentists and other health professionals is a way to prevent the occurrence of this condition.

Assessing the risk of an excess fluoride intake among Swedish children in households with private wells--expanding static single-source methods to a probabilistic multi-exposure-pathway approach

It is often assumed that water consumption is the major route of exposure for fluoride and analysis of water fluoride content is the most common approach for ensuring that the daily intake is not too high. In the present study, the risk of excess intake was characterized for children in households with private wells in Kalmar County, Sweden, where the natural geology shows local enrichments in fluorine. By comparing water concentrations with the WHO drinking water guideline (1.5 mg/L), it was found that 24% of the ca. 4800 sampled wells had a concentration above this limit, hence providing a figure for the number of children in the households concerned assessed to be at risk using this straightforward approach. The risk of an excess intake could, alternatively, also be characterized based on a tolerable daily intake (in this case the US EPA RfD of 0.06 mg/kg-day). The exposure to be evaluated was calculated using a probabilistic approach, where the variability in all exposure factors was considered, again for the same study population. The proportion of children assessed to be at risk after exposure from drinking water now increased to 48%, and when the probabilistic model was adjusted to also include other possible exposure pathways; beverages and food, ingestion of toothpaste, oral soil intake and dust inhalation, the number increased to 77%. Firstly, these results show how the risk characterization is affected by the basis of comparison. In this example, both of the reference values used are widely acknowledged. Secondly, it illustrates how much of the total exposure may be overlooked when only focusing on one exposure pathway, and thirdly, it shows the importance of considering the variability in all relevant pathways.

Toothpaste Utilization Profiles among Preschool Children

BACKGROUND

Oral healthcare for pre-school children is given due priority, as their oral health will determine the oral health status of future generations. Generally, the type, frequency and quantity of toothpaste used by children are based purely on parental preferences.

METHODOLOGY

A descriptive, cross-sectional study was conducted among mothers of preschool children by using a questionnaire.

RESULTS

Sixty two percent (n=154) mothers started brushing their children's teeth more than one year after eruption of their teeth. A majority of the mothers used adult toothpaste to brush their children's teeth and supervised their children while brushing. Fiftytwo percent mothers were aware about presence of fluoride in tooth paste but its clinical significance. Half the mothers applied full length of tooth paste to their children's brushes and most mothers made their children brush their teeth twice daily.

CONCLUSION

Based on the findings of this study, it appears that there is still much lack of awareness on the proper guidelines on the selection and usage of toothpastes in children. Dental professionals should use this knowledge to help and motivate parents to properly supervise and assist their children's brushing, with the goal of reducing the potential risk of fluorosis.

Fluoridated toothpaste: usage and ingestion of fluoride by 4- to 6-yr-old children in England

Fluoridated toothpaste is effective for dental caries control, yet may be a risk factor for dental fluorosis. This study aimed to quantify fluoride ingestion from toothpaste by children and to investigate the effects of age, gender, and social class on the amount of fluoride ingested per toothbrushing session. Sixty-one children, 4-6 yr of age, were recruited: 38 were from low socio-economic (LSE) areas of Newcastle, UK, and 23 were from high socio-economic (HSE) areas of Newcastle, UK. All expectorated saliva, rinse water (if used), and residual toothpaste were collected after brushing at home and were analysed for fluoride. Of the children, 74% and 69% from HSE and LSE areas, respectively, claimed that they brushed twice per day. The mean (SD) weight of toothpaste dispensed was 0.67 (0.36) g. The mean (SD) amount of fluoride ingested per toothbrushing session and per day was 17.0 (14.7) and 29.3 (32.8) μg kg(-1) of body weight, respectively. Daily fluoride intake per kilogram of body weight did not differ significantly between children from LSE and HSE areas. Fluoride intake per toothbrushing session was significantly influenced by weight of toothpaste, its fluoride concentration, and the child's age. Whilst the average amount of toothpaste used per toothbrushing session was more than twice the recommended amount (of 0.25 g), only one child had a daily fluoride intake that exceeded the tolerable upper intake level of 0.1 mg kg(-1) of body weight for this age group.

Effective Use of Self-care Fluoride Administration in Asia

The caries-preventive benefits of fluoride are generally accepted by dental researchers and practicing professionals worldwide. The benefits of fluoride toothpastes and mouthrinses have been supported by several high-quality systematic reviews. The formulation of a fluoride toothpaste and biological (salivary flow rate) and behavioral factors (brushing frequency, brushing time, post-brushing rinsing practices, timing of brushing, and amount of toothpaste applied) can influence anticaries efficacy. Fluoride mouthrinses have simpler formulations and can have better oral fluoride retention profiles than fluoride toothpastes, depending on post-brushing rinsing behaviors. Fluoride continues to be the mainstay of caries control; however, there is still the need to determine the most effective approach for fluoride utilization in children and adults who remain caries-active.

Fluoride intake from drinking water and dentifrice by children living in a tropical area of Brazil

Objective:

To assess fluoride (F^-) intake from water and toothpaste by children aged 18 to 36 months and to monitor the F^- concentrations in the drinking water system in a tropical city of Brazil.

Methods:

Children (n=58) aged 18-36 months, all lifetime residents of Penedo, state of Alagoas, Brazil, participated in this study. Water F^- analyses were carried out in 7 different occasions at least a week apart. For 2 days all the water drunk by each child was accounted for. Fluoride intake from water for each child was estimated using the mean F^- concentration of water in 7 different occasions. Fluoride intake from toothpaste was estimated by subtracting the recovered post-brushing F^- from the original amount placed in the toothbrush. The F^- intake from water and toothpaste was estimated by dividing the total amount of F^- ingested by the weight of each child.

Results:

The mean F^- concentration in the drinking water was 0.94 ppm (mean range 0.78-1.1 ppm), which is above the 0.7 ppm recommended for this area of Brazil. Mean total F^- intake from water and toothpaste was 0.128 mg F^-/Kg Body Weight/day. The daily means of F^- intake from water and toothpaste were 0.021 and 0.107 mg F^-/Kg Body Weight, respectively. Ninety six percent of children showed F^- intake above 0.07 mg F^-/Kg Body Weight/day.

Conclusions:

Children in Penedo are at risk for developing dental fluorosis due to high F^- intake from fluoridated toothpastes. Water fluoridation showed low contribution to the total F^- intake. However, high water F^- concentrations in the water indicate the need of surveillance of the artificial water fluoridation system.

Fluoride concentration in dentin of exfoliated primary teeth as a biomarker for cumulative fluoride exposure

A biomarker for lifetime fluoride exposure would facilitate population-based research and policy making but currently does not exist. This study examined the suitability of primary tooth dentin as a biomarker by comparing dentin fluoride concentration and fluoride exposures. Ninety-nine children's exfoliated primary teeth were collected from 2 fluoridated and 2 fluoride-deficient communities in North Carolina. Coronal dentin was isolated by microdissection and fluoride concentration assayed using the microdiffusion, ion-specific electrode technique. Information on children's fluoride exposures since birth from drinking water, toothpaste, supplements, rinses, food and beverages was collected by a self-reported questionnaire administered to caregivers. Only a small portion of the variance (10%) in incisor dentin fluoride (mean 792, SD 402 mg/kg) was accounted for by the best linear regression model as evaluated by the adjusted R(2). A moderate portion of the variance (60%) of molar dentin fluoride (mean 768, SD 489 mg/kg) was predicted by dietary fluoride supplement exposures, community of residence, and frequent tea consumption. Results for molars suggest that primary tooth dentin concentration may prove to be a satisfactory biomarker for fluoride exposure.

A half-century of community water fluoridation in the United States: review and commentary

The nearly 50-year history of community water fluoridation is reviewed with the major emphasis on the benefits and safety of fluoridation. Other aspects of water fluoridation also described include the apparent reduction in measurable fluoridation benefits because of the abundance of other fluoride sources, the diffusion of fluoridation effects into fluoride-deficient communities, preeruptive and posteruptive effects, technical and cost aspects, sociopolitical and legal issues that affect the successful fluoridation of communities, and alternatives to community water fluoridation. The majority of studies have evaluated the effectiveness of water fluoridation on the permanent teeth of children, while there are fewer studies on deciduous teeth and in adults; the relationship between fluoride ingestion and bone health needs further clarification; the sociopolitical issues of fluoridation need to be better understood.

Fluoride intake by children at risk for the development of dental fluorosis: comparison of regular dentifrices and flavoured dentifrices for children

The aim of the present study was to determine fluoride intake by children at risk of dental fluorosis according to the type of dentifrice used. Forty-two volunteers aged between 20 and 30 months, from 2 kindergartens, were supervised while brushing their teeth with regular dentifrices (nominally 1,500 ppm F) and dentifrices flavoured for children (nominally 1,100 ppm F), brushing 3 times with each type in random order to minimize bias. The amount of fluoride ingested was determined by subtracting the weight of dentifrice recovered from the weight used and calculating the mean of the 3 brushings. Fluoride was analyzed with specific electrodes. Parents were asked how often the children brushed their teeth and the daily tooth brushing frequency was used to calculate the daily fluoride intake. The average fluoride intake using regular dentifrices and those flavoured for children was 0.567 +/- 0.300 and 0.630 +/- 0.320 mg F/day, respectively, corresponding to doses of 0.046 +/- 0.023 and 0.051 +/- 0.026 mg F/kg/day (p > 0.05). Fluoride intake was slightly higher with the use of dentifrices flavoured for children. Moreover, the dose to which children were exposed with either type of dentifrice was very close to that which is considered the limit (0.05-0.07 mg F/kg/day).

Effects of toothbrush size and dentifrice type/brand on pea-sized and larger amounts of dentifrice

PURPOSE

To assess the effects of toothbrush size and dentifrice type/brand on amounts of dentifrice being placed when trying to replicate pictures with different amounts of dentifrice, including a pea-sized amount.

METHODS

This laboratory trial used one researcher to repeatedly dispense five dentifrice products on three different child-sized toothbrushes using a standard procedure. Two sets of drawings, depicting the recommended pea-sized and larger amounts, were used as guides in an effort to place the same amount each time. Data were analysed using ANOVA.

RESULTS

Amounts of dentifrice placed on the two larger toothbrushes were significantly greater than those placed on the smallest toothbrush (p < 0.0001). The amounts placed on the two larger toothbrushes with similar brushing areas but different shapes were not significantly different from each other. The effect of dentifrice type/brand varied in each analysis. For pea-sized amounts, one of 10 pairwise comparisons was significant. For amounts larger than pea-sized, another pair of the 10 pairwise comparisons was significant. However, there was no significant effect of dentifrice type/brand when considering both pea-sized and larger amounts together in the same analysis.

CONCLUSIONS

Toothbrush size significantly affected the amount of dentifrice placed for both pea-sized and larger amounts. The amounts placed on larger size toothbrushes were greater than on the smaller size toothbrush. No consistent effects of selected dentifrices were found.

Total fluoride intake and urinary excretion in 4–year–old Iranian children residing in low-fluoride areas

Knowledge of levels of fluoride ingestion and excretion is important in planning optimum fluoride therapy for young children. In previous literature, it has been assumed that only about one-third of ingested fluoride is excreted in young children. The aims of the present study were (a) to measure total fluoride intake, urinary fluoride excretion and fluoride balance, and (b) to investigate the effect of air temperature on fluoride intake and urinary fluoride excretion, in young children. Children (4 years old) living in a city, a small town and rural areas of Fars province, Iran, where drinking water contained 0·30–0·39 mg F/l, were invited to participate. Selection of subjects was by random sampling of kindergartens or health centres. The children were surveyed twice, once in summer and once in winter. Diet was obtained by 3 d diaries with interview. Samples of most foods and drinks were analysed for fluoride content. Ingestion of fluoride from toothpaste was estimated for each child. Each child's urine was collected over 24 h and analysed for fluoride content. Seventy-eight of the 116 volunteers completed all aspects of the study, which was conducted in 1995–6. For all children, the mean fluoride ingestion from diet was 0·390 (sd 0·122) mg/d or 0·028 (sd 0·008) mg/kg body weight per d. Fluoride ingestion from diet was higher in summer and higher in rural areas. The mean ingestion of fluoride from all sources was 0·426 (sd 0·126) mg/d and the mean fluoride urinary excretion was 0·339 (sd 0·100) mg/d. The difference between ingestion and urinary excretion was +0·087 (sd 0·143) mg, equivalent to 80 % excretion. Faecal excretion was not estimated. The results indicate fluoride retention at 4 years to be much lower than previously assumed.

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The purpose of this study was to assess the amount of ingested fluoride and the fluoride dose to which children are subjected during toothbrushing with a conventional dentifrice (1500 ppmF) and a children's dentifrice with special flavor (1100 ppmF) and evaluate the influence of rinsing and expectoration after brushing. Six brushings followed by 6 residue collections (3 per dentifrice) were performed by 42 Brazilian children (aged 20 to 30 months). The concentration of fluoride in the residues and dentifrices was determined. The amount ingested was obtained by the difference principal. 64.3% of the children did not expectorate or rinse after brushing. For both toothpastes, no significant difference was found for fluoride doses comparing children that rinsed to those that did not rinse (p³ 0.05). When children's toothpaste was used, children who did not expectorate were exposed to a higher dose than those who did expectorate (p=0.032). The same was not observed when conventional toothpaste (p=0.081) was used. In conclusion, rinsing and expectoration after brushing had no influence on the dose of fluoride to which children were exposed by use of the dentifrices. However, expectoration was directly associated to the fluoride dose when the children's dentifrice was used.

Fluoride exposure from ingested toothpaste in 4-5-year-old Malaysian children

OBJECTIVE

The aim of this study was to assess (by direct determination) the fluoride (F) exposure from ingested toothpaste among 4-5-year-old Malaysian children.

METHODS

This was part of a larger study to determine fluorosis status and F exposures. A total of 1343 10-11-year-old subjects were sampled by two-stage systematic random sampling for assessment of fluorosis. Two hundred 4-5-year-old siblings of these index subjects were sub-sampled for determination of F exposures from ingested toothpastes and other sources. Estimations of F ingested from toothpaste (FI) was made by the method of difference between 'F in toothpaste taken for use' and the 'F in toothpaste used but not swallowed', by the duplicate technique under normal home conditions. F ions were determined with the combination selective ion electrode.

RESULTS

The subjects ingested 32.9% of the toothpaste placed on the brush. Fluoride exposure from ingested toothpaste was highly variable and the mean was 426.9 +/- 505.5 microg (SEM 38.9)/48 h, or 213.5 microg/day and 131.9 microg per brushing.

CONCLUSIONS

The amount of ingested fluoride (FI) per brushing in this study was the lowest of all studies reporting this parameter and was within the pea-size range of 125-250 microg. Because of the highly statistically significant correlations between the FI from toothpaste and the amount of toothpaste dispensed (Pearson's correlation coefficient 0.647, P = 0.000), parents should assume responsibility for placement of toothpaste and limit the amount of toothpaste used.

Development of a standardized method for comparing fluoride ingested from toothpaste by 1.5-3.5-year-old children in seven European countries. Part 1: Field work

OBJECTIVES

To develop a standardized method for measuring the variables affecting fluoride ingestion from toothpaste in young children between the ages of 1.5 and 3.5 years, and to use the method at seven European sites.

METHODS

Random samples of children were invited to take part in the study. Parents who gave consent were visited at home. The children brushed their teeth using the toothpaste brand and toothbrush type currently in use. Variables measured were: type of toothpaste used, fluoride concentration of toothpaste used, weight of toothpaste used, frequency of brushing and body weight of the child.

RESULTS

It was not possible to follow the agreed protocol in all seven countries and in three countries appropriate alternative methods were employed. There was considerable variation between countries in the variables investigated. Use of children's toothpaste ranged from 69% in Ireland to 98% in Portugal. In the Netherlands up to 60% of the children were using toothpaste containing <400 ppm F and in Finland up to 27% of children were using toothpaste containing >1200 ppm F. Over half of the children used <0.25 g of toothpaste per brushing and the majority of children brushed once or twice per day.

CONCLUSION

Although adherence to the agreed protocol was not possible at all study sites there was a clear picture of considerable variation in the oral hygiene practices of young children throughout Europe.

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.

Caries risk assessment and prevention: strategies for Head Start, Early Head Start, and WIC

OBJECTIVES

This review updates the evidence regarding caries risk assessment for infants, toddlers, and preschool children and formulates recommendations for preventive strategies for WIC, Head Start, and Early Head Start.

METHODS

Literature on caries risk assessment and preventive strategies for infants, toddlers, and preschool children were reviewed and synthesized. Recommendations for WIC, Head Start, and Early Head Start were made based on the review.

RESULTS

Individual caries risk for children in WIC, Head Start, and Early Head Start should be based on: (1) previous caries experience, (2) precavity lesions, (3) visible plaque, and (4) perceived risk by examiners. Recommended preventive strategies for WIC and Head Start populations include: (1) daily toothbrushing in Head Start centers using fluoridated toothpaste; (2) fluoride varnish application to children enrolled in WIC, Head Start, and Early Head Start; (3) use of chlorhexidine gels and varnishes (following FDA approval); and (4) increased use of sealants on children with precavity pit and fissure lesions.

CONCLUSIONS

Early screening, risk assessment, and preventive programs in WIC, Head Start, and Early Head Start populations hold a great deal of promise for preventing dental decay in high-risk children.

Total fluoride intake and implications for dietary fluoride supplementation

This paper reviews the history and validity of recommended "optimal" levels of systemic fluoride intake and the available information on levels of fluoride intake in young children from foods and beverages (including water), dentifrices, dietary fluoride supplements, mouthrinses, and gels. Most of the studies emphasize the substantial variation in ingestion among individuals. Often, a substantial proportion of individuals received fluoride well beyond the mean exposure reported in the study. Limitations in the existing data make it difficult to determine the total distribution of fluoride intake from all sources. Therefore, hypothetical combinations of possible daily fluoride intake from the three main sources (diet, dentifrices, and supplements) are presented for those aged 6, 12, 24, and 36 months, with associated mean intake per kg body weight. Findings suggest that some children exceed the "optimal" level of fluoride intake from single sources alone, while others can from a combination of sources. Moreover, if current recommended "optimal" levels, which have been derived on an empirical basis, are actually lower than what has been quoted in the literature, then more children could be ingesting excessive amounts of fluoride, which could increase their risk of developing objectionable dental fluorosis. The variation and complexity of fluoride ingestion from all sources should be considered in the evaluation of recommendations for use of dietary fluoride supplements.

Fluoride ingestion from toothpaste by young children

OBJECTIVE

To investigate the reported and observed brushing habits of young children and their ingestion of fluoride from toothpaste.

DESIGN

In 1997, a random sample of 50 children, aged 30 months, from three districts in the North West region of England, were visited at home.

METHODS

The reported and observed toothbrushing behaviour was determined and the weight of toothpaste applied to the toothbrush was measured. The amount of fluoride retained in the mouth after brushing with either a 400 ppm F or 1,450 ppm F toothpaste was determined.

RESULTS

All parents claimed that their children's teeth were being brushed with a fluoride toothpaste at least once daily. The mean amount of toothpaste applied on the brush was 0.36 g of which 0.27 g (72%) was retained in the mouth. The mean amount of fluoride ingested per brushing was 0.42 mg when using the 1,450 ppm F toothpaste and 0.10 mg when using the 400 ppm F toothpaste. Although most parents applied a small amount of toothpaste a small minority applied a large amount. If using the 400 ppm F toothpaste twice daily no children of average weight would have exceeded ingestion of 0.05 mgF/kg body weight whereas 14 average weight children would have exceeded this value if using the 1450 ppm F toothpaste.

CONCLUSIONS

It is essential that parents of children aged less than 7 years apply a small (pea-sized) amount of fluoride toothpaste on the toothbrush and discourage swallowing.

Changes in dental fluorosis and dental caries in Newburgh and Kingston, New York

OBJECTIVES

This study sought to determine whether the prevalence of dental fluorosis and dental caries had changed in a fluoridated community and a nonfluoridated community since an earlier study conducted in 1986.

METHODS

Dental fluorosis and dental caries data were collected on 7- to 14-year-old lifelong residents (n = 1493) of Newburgh and Kingston, NY.

RESULTS

Estimated dental fluorosis prevalence rates were 19.6% in Newburgh and 11.7% in Kingston. The greatest disparity in caries scores was observed between poor and nonpoor children in nonfluoridated Kingston.

CONCLUSIONS

The prevalence of dental fluorosis has not declined in Newburgh and Kingston, whereas the prevalence of dental caries has continued to decline.

Fluorosis risk from early exposure to fluoride toothpaste

Swallowed fluoride toothpaste in the early years of life has been postulated to be a risk factor for fluorosis, but the epidemiological evidence is weakened by the fact that most of the relevant studies were done in developed countries where an individual is exposed to multiple sources of fluoride.

OBJECTIVES

To quantify the risk of fluorosis from fluoride toothpaste in a population whose only potential source of fluoride was fluoride toothpaste.

METHODS

Case-control analyses were conducted to test the hypothesis that fluoride toothpaste use before the age of 6 years increased an individual's risk of fluorosis. Data came from a cross-sectional clinical dental examination of schoolchildren and a self-administered questionnaire to their parents. The study was conducted in Goa, India. The study group consisted of 1189 seventh grade children with a mean age of 12.2 years.

RESULTS

The prevalence of fluorosis was 12.9% using the TF index. Results of the crude, stratified, and logistic regression analyses showed that use of fluoride toothpaste before the age of 6 years was a risk indicator for fluorosis (OR 1.83, 95% CI 1.05-3.15). Among children with fluorosis, beginning brushing before the age of 2 years increased the severity of fluorosis significantly (P<0.001). Other factors associated with the use of fluoride toothpaste, such as eating or swallowing fluoride toothpaste and higher frequency of use, did not show a statistically significant increased risk for prevalence or severity of fluorosis.

CONCLUSIONS

Fluoride toothpaste use before the age of 6 years is a risk indicator for fluorosis in this study population.

Risk factors associated with fluorosis in a non-fluoridated population in Norway

In Norway, there is no water fluoridation and little naturally occurring fluoride in drinking water. Fluoride toothpaste is used by 95% of the population and there is a long tradition of fluoride supplement use. The purpose of this study was to record the prevalence and severity of dental fluorosis in 8-year-old children and relate this to systemic fluoride exposure (supplements and toothpaste). All children (n = 551, born 1988) in a municipality in Norway were invited to participate. Dental fluorosis on the buccal surface of the upper permanent incisors was recorded according to the Thylstrup-Fejerskov index (TF). Parents provided data on use of supplements and toothpaste. Complete data were obtained from 383 children. Sixty-seven percent of the children had used fluoride supplements regularly during childhood. At 8 months or earlier, the teeth of 26% of the children, and at age 14 months or earlier the teeth of 82%, were being brushed. Among children who used fluoride supplements regularly, periodically, seldom and not at all, 45%, 21%, 10% and 0%, respectively, had dental fluorosis. The dental fluorosis was mild (TF = 1) in 87% of the cases. Bivariate and multivariate analyses showed that, in addition to use of fluoride supplements, starting toothbrushing at an early age was associated with higher prevalence of dental fluorosis. The child's birth weight and liking for or swallowing of toothpaste did not influence the prevalence of fluorosis. Risk factors for fluorosis were use of toothpaste before the age of 14 months and regular use of fluoride supplements during childhood.

Sources of fluoride intake in children

Wide variations in fluoride intake among children make estimating fluoride intake difficult. This paper discusses the various sources of fluoride intake among children, beginning with a review of the fluoride concentrations of water and other beverages, foods, and therapeutic fluoride products. A review of previous studies' estimates of fluoride intake from diet, dentifrice, fluoride supplements, fluoride mouthrinses, and gels, as well as total fluoride intake also is presented. Then, estimates of fluoride intake among young children of different age groups are summarized, and examples demonstrating the high level of variability of fluoride intake, both from individual sources and in total, are presented. Lastly, this paper discusses the implications of our current level of knowledge of children's fluoride intake, and presents recommendations for the use of fluoride for children in light of this current knowledge. The major recommendations are that: (1) the fluoride content of foods and beverages, particularly infant formulas and water used in their reconstitution, should continue to be monitored closely in an effort to limit excessive fluoride intake; (2) ingestion of fluoride from dentifrice by young children should be controlled, and the use of only small quantities of dentifrice by young children should be emphasized; and (3) dietary fluoride supplements should be considered a targeted preventive regimen only for those children at higher risk for dental caries and with low levels of ingested fluoride from other sources.

Review of fluoride exposures and ingestion

The literature on fluoride intake/ingestion was reviewed critically to determine the current exposure to fluorides for children living in non-fluoridated and fluoridated areas in North America. Fluoride from all sources except mouthrinses and professionally applied topical fluorides was considered, including ingestion from foods and beverages, as well as intake from the use of fluoride dentifrice and dietary fluoride supplements. Data from all of these sources were used to produce estimates of mean daily ingestion. Studies consistently have identified substantial variation in ingestion among individuals. These analyses demonstrated that a substantial proportion of individuals had exposure or ingestion well beyond that of the mean for each source, and often 10-20% received up to several times as much exposure as the mean. Some children probably ingest sufficient fluoride from a single source to exceed the "optimal" fluoride intake recommended from all sources, and are therefore at increased risk of fluorosis. This review highlighted the substantial variation and complexity of fluoride ingestion. Appropriate consideration of these aspects is warranted in efforts to ensure a margin of safety favoring dental caries prevention while limiting objectionable fluorosis.

Dentifrice use among preschool children

Ingestion of fluoridated dentifrice by young children may be a major contributing factor to dental fluorosis, prevalent in the United States. Brushing habits of a small group of preschoolers were monitored to document parental involvement and amounts of dentifrice used.