Fluoride intake from beverage consumption in a sample of North Carolina children

Effects of high fluoride content in livestock drinking water on milk samples of different cattle in endemic area of Pakistan: risk assessment for children

Fluoride in trace quantity is beneficial for human beings, serving to strengthen the apatite matrix of skeletal tissues and teeth, whereas high intake causes adverse impacts. In the present study, the effect of fluoride-contaminated drinking water of livestock on the milk samples of different cattle, belonging to a fluoride-endemic area (Tharparkar, Pakistan), was studied. In milk samples of different cattle (cows, camels, sheep, and goats), free and bound fluoride forms and its total (free (F^-) + bound (F^-)) contents were measured by ion-selective electrode. The concentration of fluoride in drinking water of livestock was also analyzed, as found in the range of 11.8-33.5 mg/L. The concentration of total fluoride in the milk samples of sheep, goats, cows, and camels were observed in the range of 1.72-2.43, 1.40-2.03, 0.835-1.41, and 0.425-0.897 mg/L, respectively. The resulted data indicated that the concentration of fluoride was higher in the milk samples of smaller cattle (sheep and goat), as compared to cow and camel. The fluoride in milk samples of all cattle appeared dominantly in free form. The percentage values of bound fluoride in the milk samples of sheep, goats, and cows were found to be 6.76, 11.6, and 19.7% in total, respectively, while in camel milk, the percentage was below the detection limit. The estimated daily intake of fluoride contents on consuming different types of milk by children age ranged 1.0 to 3.0 years was evaluated. Graphical abstract ᅟ.

Fluoride intake from fluids and urinary fluoride excretion by young children in Kuwait: a non-fluoridated community

OBJECTIVES

To determine the pattern of fluid consumption, fluoride intake from the fluids and urinary fluoride excretion by children aged 1-9 years in Kuwait, a nonfluoridated community.

METHODS

Using the cluster sampling technique, children aged 1-9 years were chosen from 2000 randomly selected households in Kuwait. Questionnaires were then administered to their mothers to determine the children's daily fluid intake. Fluoride concentrations in tap water as well as all brands of bottled water and beverages consumed by the children were measured, using the fluoride ion-specific electrode. Fluoride excretion was determined in 400 randomly selected children, based on fluoride/creatinine ratio.

RESULTS

The mean daily fluid consumption by the children was high, being 1115-1545 ml. About 40% of the fluid intake was plain (tap and bottled) water and approximately 10% of the children drank bottled water exclusively. Fluoride concentration in tap water was low (0.04±SD 0.02 ppm), but was higher in bottled water (0.28±SD 0.40 ppm). Mean daily fluoride ingestion from fluids was 0.013-0.018 mg/kg body weight (bw). Even after allowing for fluoride ingestion from other sources, mean daily fluoride ingestion was still below 0.1 mg/kg bw set by the United States of America Institute of Medicine as the lowest-observed-adverse-effect level for moderate enamel fluorosis in children aged up to 8 years. Furthermore, the mean daily urinary fluoride excretion of 128-220 μg was below the provisional standard of 360-480 μg for optimal fluoride usage by children aged 3-5 years.

CONCLUSION

Fluoride ingestion from fluids and urinary fluoride excretion by the children were below the recommendations for optimal fluoride usage. Thus, there is room for an upward adjustment of fluoride level in public drinking water supplies in Kuwait, as a caries preventive measure.

Associations between fluorosis of permanent incisors and fluoride intake from infant formula, other dietary sources and dentifrice during early childhood

OBJECTIVES

The authors describe associations between dental fluorosis and fluoride intakes, with an emphasis on intake from fluoride in infant formula.

METHODS

The authors administered periodic questionnaires to parents to assess children's early fluoride intake sources from beverages, selected foods, dentifrice and supplements. They later assessed relationships between fluorosis of the permanent maxillary incisors and fluoride intake from beverages and other sources, both for individual time points and cumulatively using area-under-the-curve (AUC) estimates. The authors determined effects associated with fluoride in reconstituted powdered infant formulas, along with risks associated with intake of fluoride from dentifrice and other sources.

RESULTS

Considering only fluoride intake from ages 3 to 9 months, the authors found that participants with fluorosis (97 percent of which was mild) had significantly greater cumulative fluoride intake (AUC) from reconstituted powdered infant formula and other beverages with added water than did those without fluorosis. Considering only intake from ages 16 to 36 months, participants with fluorosis had significantly higher fluoride intake from water by itself and dentifrice than did those without fluorosis. In a model combining both the 3- to 9-months and 16- to 36-months age groups, the significant variables were fluoride intake from reconstituted powder concentrate formula (by participants at ages 3-9 months), other beverages with added water (also by participants at ages 3-9 months) and dentifrice (by participants at ages 16-36 months).

CONCLUSIONS

Greater fluoride intakes from reconstituted powdered formulas (when participants were aged 3-9 months) and other water-added beverages (when participants were aged 3-9 months) increased fluorosis risk, as did higher dentifrice intake by participants when aged 16 to 36 months.

CLINICAL IMPLICATIONS

Results suggest that prevalence of mild dental fluorosis could be reduced by avoiding ingestion of large quantities of fluoride from reconstituted powdered concentrate infant formula and fluoridated dentifrice.

Microtensile bond strength of porcelain laminate veneers bonded to fluorosed teeth

PURPOSE

The aim of this study was to evaluate the microtensile bond strengths (MTBSs) of porcelain laminate veneers bonded to normal and fluorosed teeth.

MATERIALS AND METHOD

Forty human incisors, including 20 normal and 20 moderately fluorosed teeth [Thylstrup Fejerskov Index (TFI) = 4 to 6], were collected. The labial surfaces of the teeth were ground up to 1 mm and polished with #600 silicon carbide abrasive paper. The surfaces were bonded to 1-mm-thick ceramic slices (5 x 5 mm(2)) previously made (VitaVM7) using one of two ceramic cement systems (RelyX or Clapearl) following the manufacturers' instructions. A resin composite was added on top of the ceramic slices and built up to 5-mm thickness to serve as grips. The specimens were stored in water (37 degrees C) for 24 hours, and beams of adhesive interface with a surface area of approximately 1.25 mm(2) were obtained. Then the beams were subjected to MTBS tests at a crosshead speed of 1.0 mm/min. The data were analyzed with two-way ANOVA.

RESULTS

The results of the MTBS test (MPa) were 20.55 +/- 5.83 (RelyX/fluorosed), 20.16 +/- 4.61 (RelyX/normal), 18.74 +/- 2.88 (Clapearl/fluorosed), and 21.06 +/- 4.99 (Clapearl/normal). There were no significant differences in the MTBSs among the four groups (p > 0.05).

CONCLUSIONS

The MTBSs of ceramic cement systems used were not influenced by the moderately fluorosed teeth.

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.

Risk factors associated with dental fluorosis in Central Plateau State, Nigeria

OBJECTIVES

Dental fluorosis is known to occur in some parts of Plateau State, but the factors responsible for its occurrence are unknown. The purpose of this study, therefore, was to determine the factors associated with the occurrence of dental fluorosis in Central Plateau.

METHODS

The study was cross-sectional and comparative in design. Subjects were selected using the multi-stage sampling technique. One Local Government Area each was randomly selected from the high and low altitude parts of the district, and from each selected Local Government Area two health districts were randomly selected with probability proportional to size. From each of the selected health districts two major settlements were selected again with probability proportional to size. Twelve- to fifteen-year-old lifelong residents of the selected settlements were then selected for study. Each respondent completed an interviewer-administered questionnaire after which he/she was clinically examined to ascertain his/her fluorosis status. Samples of water were collected from water sources consumed by the respondents in each settlement.

RESULTS

One thousand one hundred children aged 12-15 years were studied, 554 (50.4%) of which lived in the high altitude part of the district and 546 (49.6%) in the low altitude part of the district. Fluorosis prevalence was significantly associated with altitude and the fluoride level of water. The prevalence of fluorosis was significantly associated with altitude (chi(2) = 85.735, d.f. = 1, P < 0.0001) and the fluoride level of water (chi(2) for trend = 8.009, d.f. = 1, P < 0.05) in the low altitude parts of the district. None of the respondents had used fluoride-containing toothpaste before 4 years of age and none used fluoride supplements.

CONCLUSION

The occurrence of dental fluorosis in Central Plateau could be because of the high altitude of the area and the fluoride concentration of the waters consumed in the district.

Fluoride concentrations in industrialized beverages consumed by children in the city of Bauru, Brazil

The increasing consumption of juices, soft drinks and teas among children has increased significantly fluoride ingestion at the age range of risk for development of dental fluorosis.

OBJECTIVE

The purpose of this study was to evaluate fluoride concentrations in some brands of industrialized beverages consumed by children in the city of Bauru, SP, Brazil.

MATERIAL AND METHODS

98 brands of beverages were analyzed, divided into 3 lots, comprising 36, 32 and 30 brands, respectively, for the first, second and third lots. Fluoride concentrations were determined by HMDS-facilitated diffusion, using a fluoride ion-specific electrode (Orion 9409).

RESULTS

Fluoride concentrations ranged between 0.04 and 1.76 microg F/mL. It was observed a wide variation in fluoride concentrations among the different brands, as well as the different lots of the same brand. There was no information on fluoride concentrations on the labels of any product.

CONCLUSIONS

Some of the products analyzed could contribute significantly to the total fluoride intake and, thus, be important risk factors for development of dental fluorosis, which indicates the need of controlling the production of these beverages with respect to fluoride concentration.

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.

Micro-shear Bond Strength of Two All-in-one Adhesive Systems to Unground Fluorosed Enamel

The aim of this study was to evaluate the micro-shear bond strengths of two all-in-one adhesive systems to unground fluorosed enamel. Buccal surfaces of 24 normal and 24 moderately fluorosed teeth (Thylstrup and Fejerskov index, TFI=4-6) were bonded using G-Bond and Clearfil Tri-S Bond. The surfaces were then restored with a resin composite, stored for 24 hours in water, and tested for micro-shear bond strength (MSBS). Fracture modes, etching patterns, and adhesive interfaces were studied under a scanning electron microscope (SEM). Data were analyzed with two-way ANOVA, whereby no significant differences in MSBS were found among the four groups (p>0.05). Through SEM examination, it was shown that 1 microm of resin tag-like extensions had penetrated into the enamel for both adhesives at the enamel-adhesive interface. Based on the results obtained, it was concluded that MSBS was not influenced by the severity of fluorosis. Furthermore, there were no differences in enamel bond strength between G-Bond and Clearfil Tri-S Bond.

Relationship between daily fluoride intake from diet and the use of dentifrice and human plasma fluoride concentrations

The literature contains reports of the relationship between the fluoride concentrations in drinking water and human plasma. None of these studies, however, documented individual levels of daily fluoride intake, which can vary considerably among individuals served by the same water supply. Furthermore, while water can be an important source of fluoride, other sources, especially fluoridated dentifrices, also contribute substantially. This 2-day study with five 25-35-year-old subjects in each of three communities (Bauru, 0.6-0.8 ppm F; Domelia, 0.7 ppm F; Floresta, 0.3 ppm F) determined plasma fluoride concentrations and fluoride intake from diet and the use of dentifrice which, together, approximate total daily fluoride intake. The purposes were to determine: (1) the extent to which plasma fluoride concentrations approached levels known to affect the quality and quantity of bone; (2) the relationship between fluoride intake and plasma concentrations. Plasma was collected at 4-h intervals starting at 0800 h and ending at 2000 h each day. Average fluoride intakes from diet and the use of dentifrice in the three communities ranged from 0.16 to 0.82 mg/day and from 0.29 to 3.16 mg/day, respectively. The overall average plasma concentrations in the three communities were 0.44, 0.45 and 0.54 micromol/l (P<0.005). They were directly related to intake from the use of dentifrice (P=0.030) and to total intake (P=0.033), but were not related to dietary intake (P=0.176). In conclusion, despite fluoride intake from various sources, the plasma fluoride concentrations of the study subjects remained at levels far below those associated with effects on bone production.

Pattern of fluid consumption in a sample of Saudi Arabian adolescents aged 12-13 years

OBJECTIVE

To study the pattern of fluid consumption in a group of Saudi adolescent boys and girls aged 12-13 years.

DESIGN

Prospective study.

METHODS

Three hundred forty-four boys and girls attending school in Riyadh recorded their fluid intake for three consecutive days, including one weekend day, in April and May 2002. Types of drink/beverage and total amount consumed were analysed and ranked in order of amount/quantity of consumption. Independent samples t-test was used to compare between genders.

RESULTS

Mean daily fluid intake was 1,917 mL (SD 287). Drinking water provided 37%, whereas carbonated soft drinks and fruit juice/drink accounted for 26% and 25%, respectively. Seven percent of total fluid intake amounting to 134 mL came from milk and 5% (103 mL) was from tea/coffee. Fluid intake was higher in boys (2,006 mL) than in girls (1,821 mL) (P=0.049). This was also true for carbonated soft drinks (P=0.050) and tea/coffee (P=0.000). Girls consumed more milk (P=0.001) and fruit juice/drink (P=0.001) than boys.

CONCLUSION

Both carbonated soft drink and fruit juice/drink accounted for the largest proportion of total fluid intake by the sampled Saudi adolescents to the detriment of nutritious milk.

Conhecimento dos médicos pediatras e odontopediatras de Bauru e Marília a respeito de flúor

A proposta deste trabalho foi verificar o conhecimento dos médicos pediatras e odontopediatras, a respeito dos compostos fluoretados. Para tanto, foram visitados 91 médicos pediatras e 72 odontopediatras dos municípios de Bauru e Marília, que ao concordarem em participar da pesquisa receberam um questionário com 22 questões. O preenchimento e a devolução foram imediatos. Os dados obtidos foram analisados por meio de estatística descritiva, utilizando freqüências absolutas e relativas, representadas através de tabelas. Mediante a análise dos questionários, verificou-se que alguns polivitamínicos que contêm flúor são usualmente prescritos pelos médicos pediatras, ao passo que os géis, vernizes e soluções para bochecho são bastante empregados pelos odontopediatras. Não foi estabelecida relação entre o conhecimento e tempo de formado, a idade do profissional, a universidade de origem, a cidade em que trabalha e a área de atuação (particular, rede pública ou em ambos) desses profissionais. Os resultados obtidos sugerem que o conhecimento dos médicos pediatras e odontopediatras, das cidades de Bauru e de Marília, a respeito da presença de flúor em várias fontes de ingestão se mostrou insuficiente e, em algumas situações, preocupante, com relação à prevenção de fluorose dentária.

Fluoride Intake from Food and Liquid in Japanese Children Living in Two Areas with Different Fluoride Concentrations in the Water Supply

The purpose of this study was to estimate the average daily amount of fluoride from the diet ingested by Japanese children of ages susceptible to dental fluorosis in two areas with different fluoride concentrations in the water supply. Thirty-eight children aged 2-8 years participated in a survey of fluoride intake. Twenty-one out of 38 children lived in an area in which the community water fluoride concentration was an average of 0.555 ppm (moderate fluoride area: MFA), and 17 lived in a low fluoride area (LFA), which ranged between 0.040 and 0.131 ppm. To measure the fluoride intake, diets were collected with a duplicate-diet technique. The fluoride concentrations in each sample were measured using the diffusion technique of Taves and the electrode technique. Meanwhile, after clinical examinations for dental caries and fluorosis, 228 subjects aged 13-15 years were selected for analysis from the same communities. The mean DMFT in the MFA was significantly lower than that in the LFA. The severest grade of dental fluorosis observed was 'very mild' according to Dean's fluorosis index in both areas. The total daily fluoride intakes were 0.0252-0.0254 mg F/kg/day in the MFA and 0.0126-0.0144 mg F/kg/day in the LFA. Differences in the fluoride concentration of drinking water in this study were reflected in the fluoride intake from the diet in a typical Japanese diet.

Health risks of enteric viral infections in children

Children are at a greater risk of infections from serious enteric viral illness than adults for a number of reasons. Most important is the immune system, which is needed to control the infection processes. This difference can lead to more serious infections than in adults, who have fully developed immune systems. There are a number of significant physiological and behavioral differences between adults and children that place children at a greater risk of exposure and a greater risk of serious infection from enteric viruses. Although most enteric viruses cause mild or asymptomatic infections, they can cause a wide range of serious and life-threatening illnesses in children. The peak incidence of most enteric viral illnesses is in children <2yr of age, although all age groups of children are affected. Most of these infections are more serious and result in higher mortality in children than adults. The fetus is also affected by enterovirus and infectious hepatitis resulting in significant risk of fetal death or serious illness. In addition to the poliovirus vaccine, the only vaccine available is for hepatitis A virus (HAV). A vaccine for rotavirus has currently been withdrawn, pending review because of potential adverse effects in infants. No specific treatment is available for the other enteric viruses. Enteric viral infections are very common in childhood. Most children are infected with rotavirus during the first 2yr of life. The incidence of enteroviruses and the viral enteric viruses ranges from 10% to 40% in children and is largely dependent on age. On average, half or more of the infections are asymptomatic. The incidence of hepatitis A virus is much lower than the enteric diarrheal viruses. There is no current evidence for hepatitis E virus (HEV) acquisition in children in the U.S. Enteric viral diseases have a major impact on direct and indirect health care costs (i.e., lost wages) and amount to several billion dollars a year in the U.S. Total direct and indirect costs for nonhospitalized cases may run from $88/case for Norwalk virus to $1,193/case for enterovirus aseptic meningitis. Direct costs of hospitalization ran from $887/case for Norwalk virus to $86,899/case for hepatitis A. These costs are based on 1997-1999 data. Generally, attack rates during drinking water outbreaks are greater for children than adults. The exception appears to be hepatitis E virus where young adults are more affected. However, pregnant women suffer a high mortality, resulting in concurrent fetal death. Also, secondary attack rates are much higher among children, probably because of fewer sanitary habits among this age group. Overall, waterborne outbreaks of viral disease have a greater impact among children than adults. To better quantify the impact on children, the literature hould be further reviewed for case studies of waterborne outbreaks where data are available on the resulting illness by age group. The EPA and/or Centers for Disease Control should attempt to collect these data as future outbreaks are documented.

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.

A quantitative look at fluorosis, fluoride exposure, and intake in children using a health risk assessment approach

The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake of fluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children living in hypothetical fluoridated and nonfluoridated communities. We also estimated hazard quotients for each exposure pathway and hazard indices for exposure conditions representative of central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. The exposure pathways considered were uptake of fluoride via fluoridated drinking water, beverages, cow's milk, foods, and fluoride supplements for both age groups. Additionally, consumption of infant formula for infants and inadvertent swallowing of toothpaste while brushing and incidental ingestion of soil for children were also considered. The cumulative daily fluoride intake in fluoridated areas was estimated as 0.20 and 0.11 mg/kg-day for RME and CTE scenarios, respectively, for infants. On the other hand, the RME and CTE estimates for children were 0.23 and 0.06 mg/kg-day, respectively. In areas where municipal water is not fluoridated, our RME and CTE estimates for cumulative daily average intake were, respectively, 0.11 and 0.08 mg/kg-day for infants and 0.21 and 0.06 mg/kg-day for children. Our theoretical estimates are in good agreement with measurement-based estimates reported in the literature. Although CTE estimates were within the optimum range for dental caries prevention, the RME estimates were above the upper tolerable intake limit. This suggests that some children may be at risk for fluorosis.

Fluoride content in bottled waters, juices and carbonated soft drinks in Mexico City, Mexico

OBJECTIVE

The objective of this study was to analyse 283 samples of soft drinks available in the metropolitan market of Mexico City, Mexico: 105 juices, 101 nectars, 57 carbonated drinks and 20 bottled waters.

MATERIALS AND METHODS

Samples of the beverages were analysed using an Orion 720A potentiometer and an Orion 9609BN F ion-specific electrode.

RESULTS

Fluoride concentration in the above-mentioned products ranged from 0.07 to 1.42 p.p.m. It was found that fluoride concentrations varied according to the brand, flavour and presentation of the product. The highest mean concentration of fluoride was found in the juices and cola drinks (0.67 +/- 0.38 and 0.49 +/- 0.41 p.p.m., respectively). The mean fluoride concentration for carbonated drinks was 0.43 +/- 0.36 p.p.m. Bottled waters had a fluoride concentration of 0.21 +/- 0.08 p.p.m.

CONCLUSIONS

The findings suggest that fluoride ingested through bottled drinks represents an important part of the total fluoride ingested by the population. In view of the wide variation of fluoride concentration in the tested products, it is necessary to implement regulatory guidelines for controlling its concentration in order to prevent dental fluorosis.

Patterns of fluoride intake from 36 to 72 months of age

OBJECTIVES

This paper reports on estimated daily fluoride intake from water by itself, beverages, selected foods, dentifrice, and dietary supplements, both individually and combined (mg and mg F/kg bw), among 785 children in the Iowa Fluoride Study from 36 to 72 months of age.

METHODS

Children were recruited in 1992-95, with questionnaires sent at four- to six-month intervals. Dietary fluoride intake estimates used community and individual water fluoride levels and average fluoride levels of beverages and foods prepared with water. Descriptive statistics and generalized linear models (GLM) assessed levels and associations with demographic factors.

RESULTS

There was substantial variation in fluoride intake, with some individuals' intakes greatly exceeding the means. Daily water fluoride intake estimates (in mg) increased with age, fluoride intake from other beverages and dentifrice both decreased slightly, and combined intake was quite consistent. For combined intake per unit body weight (mg F/kg bw), there was a steady decline with age. Therefore, the percentages with estimated intake exceeding possible thresholds for dental fluorosis also declined with age.

CONCLUSIONS

Daily mean fluoride intakes from single and combined sources are relatively stable from 36-72 months of age among these children.

Fluoride intake from foods, beverages and dentifrice by children in Mexico

OBJECTIVES

This investigation monitored fluoride ingestion in Mexican children who were susceptible to developing dental fluorosis.

METHODS

Total fluoride intake, from dietary and toothpaste samples, was determined in 15-36-month-old children from Mexico City and Veracruz, Mexico. A duplicate plate technique was used. Plasma fluoride levels were also determined in this group of children.

RESULTS

The children ingested a mean (+/-SD) of 0.20 +/- 0.08 and 0.18 +/- 0.07 mg fluoride/kg/day, in Mexico City and Veracruz, respectively. There was no statistically significant difference between the fluoride ingested by children in the two cities (P > 0.9). Plasma from children in Mexico City and Veracruz contained a mean of 1.30 +/- 0.81 and 0.87 +/- 0.72 micro mol fluoride/l, respectively, and these values were not significantly different.

CONCLUSIONS

Our results lead to the conclusion that mean fluoride ingested from the combination of foods and beverages was within the proposed safe threshold for fluoride intake of 0.05-0.07 mg F/kg/day. Most of the fluoride intake by these children was derived from the ingestion of fluoridated toothpaste. When all sources of ingested fluoride were added and total fluoride intake was calculated, the children, both in Mexico City and Veracruz, were ingesting amounts of fluoride well above the upper limits of the proposed safe threshold for fluoride intake.

Current and future role of fluoride in nutrition

Fluoride continues to be the cornerstone of dental caries prevention in North America and throughout the world, and there are a variety of sources of fluoride that may contribute to the dietary intakes of fluoride. Although the severe effect of chronic exposures to high levels of fluoride--skeletal fluorosis--is extremely rare in North America, dental fluorosis has become more prevalent. To address the increase in dental fluorosis prevalence, recommendations have been made to reduce fluoride ingestion early in life. These recommendations have included the introduction of lower concentration fluoride dentifrice for use by young children, labeling of the fluoride concentration of bottled water, and revised fluoride supplement guidelines to reduce or eliminate their use. Because our knowledge is incomplete regarding the amount, duration, and timing of fluoride ingestion that can result in dental fluorosis, however, further research is clearly needed before definitive recommendations can be made regarding the use of fluorides, including recommended intakes of fluoride in the diet.

Fluoride levels in drinking water in the Central Province of Saudi Arabia

BACKGROUND

This study was designed to assess the fluoride levels in drinking water in the Central Province of Saudi Arabia.

MATERIALS AND METHODS

A total of 817 water samples were collected from 260 locations in Central Saudi Arabia. An atomic absorption spectrophotometer [HACH instrument, model DR 3000] was used in the analyses of water samples for fluoride levels.

RESULTS

The results showed that fluoride levels vary between 0.00 and 6.20 ppm. About 75% and 6% of the population in Riyadh and Qassim regions, respectively, were exposed to very low fluoride levels (0.00-0.03 ppm), while less than 3% of the population in both regions were exposed to fluoride levels ranging from 0.61 to 0.80 ppm. A higher percentage of the population in Qassim than Riyadh region were exposed to high fluoride levels (>0.81 ppm); 28.63% than in Riyadh with 9.24%.

CONCLUSION

The findings of this study can serve as a baseline data for water fluoridation and other dental preventive programs in the area.

Fluoride intake in children living in a high-fluoride area in Ethiopia - intake through beverages

INTRODUCTION

The present study was conducted in Wonji Shoa, a sugar estate in the Ethiopian Rift Valley. Drinking water in the area is provided either by the Awash River or by high-fluoride ground water wells. Defluoridation plants have been installed, but are not in regular use, and fluorosis, dental as well as skeletal, is endemic. The aim of this study was to assess daily fluoride intake from drinking water and beverages in children from neighbouring villages with varying fluoride concentration in the drinking water.

SUBJECTS AND METHODS

Thirty families were selected from two of the plantation villages (A and K). The criterion for being included in the project was the presence in the household of at least one child, fully weaned and below the age of 5 years. For sampling of beverages, the duplicate portion technique was used. The fluoride concentration in the beverage samples was determined using standard methods, using a fluoride ion-selective electrode.

RESULTS

Ten of the selected households in Village A fetched water from the Awash River (1.8 mg F-/L) while five relied upon water from a local well (2.1 mg F-/L). All 15 households in Village K used water from a local well with fluoride concentration of 14.4 mg/L. The mean daily fluoride intake from drinking water and beverages during the four days, varied from 1.2 to 1.5 mg and 5.9 to 8.8 mg in Village A and K, respectively. Low variety in types of beverages consumed was reported both during the study period and through the questionnaire. Only local water was used for beverage preparation. Children who consumed milk had a reduced fluoride intake. Tea, which was part of the children's diet, was not found to be a main source of fluoride.

CONCLUSION

A2n effective defluoridation of the drinking water or a change of water source would seem to be the only options for avoidance of dental and possibly skeletal fluorosis.

Occurrence and management of dental fluorosis

The prevalence of dental fluorosis is on the increase in different parts of the world, even in areas with fluoride-deficient public water supplies. This may be due to increased use of fluoride in preventive dentistry. In some countries, exposure to apparently low fluoride concentrations in drinking water has resulted in severe dental fluorosis in some children. This underscores the importance of taking into consideration all sources of fluoride intake in a community before prescribing fluoride supplements or recommending appropriate fluoride concentration for the public water supply. Preventive management of dental fluorosis includes de-fluoridation of drinking water in endemic areas, cautious use of fluoride supplements and supervision of the use of fluoride toothpaste by children aged below 5 years. Aesthetically objectionable discolouration of fluorosed teeth may be managed by bleaching, micro-abrasion, veneering or crowning. The choice between these treatments depends on the severity of the fluorosis and this may be satisfactorily determined by the Thylstrup and Fejerskov index.

Fluoride intake and prevalence of dental fluorosis: trends in fluoride intake with special attention to infants

BACKGROUND

Although the predominant beneficial effect of fluoride occurs locally in the mouth, the adverse effect, dental fluorosis, occurs by the systemic route. The caries attack rate in industrialized countries, including the United States and Canada, has decreased dramatically over the past 40 years. However, the prevalence of dental fluorosis in the United States has increased during the last 30 years both in communities with fluoridated water and in communities with nonfluoridated water. Dental fluorosis is closely associated with fluoride intake during the period of tooth development.

METHODS

We reviewed the major changes in infant feeding practices that have occurred since 1930 and the changes in fluoride intakes by infants and young children associated with changes in feeding practices.

RESULTS AND CONCLUSIONS

Based on this review, we conclude that fluoride intakes of infants and children have shown a rather steady increase since 1930, are likely to continue to increase, and will be associated with further increase in the prevalence of enamel fluorosis unless intervention measures are instituted.

RECOMMENDATIONS

We believe the most important measures that should be undertaken are (1) use, when feasible, of water low in fluoride for dilution of infant formulas; (2) adult supervision of toothbrushing by children younger than 5 years of age; and (3) changes in recommendations for administration of fluoride supplements so that such supplements are not given to infants and more stringent criteria are applied for administration to children.

Oral health in the United States: the post-fluoride generation

Tremendous strides have been made in reducing the incidence of tooth decay, periodontal diseases, and associated loss of teeth in adults and children since the inception of community water fluoridation programs. Yet the disadvantaged and poor have not fully shared in the benefits. Other challenges to oral health remain. Oral cancer and related smoking and smokeless tobacco use remain major public health problems. Access to preventive and therapeutic dental care is far from universal. Public health programs similar in commitment to the approach of community water fluoridation programs initiated in the 1950s and 1960s are needed to address neglected oral health needs of underserved and high-risk populations in the United States.

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.

The effects of a break in water fluoridation on the development of dental caries and fluorosis

Durham, NC, fluoridated since 1962, had an 11-month cessation of fluoridation between September, 1990, and August, 1991. The purpose of this study was to assess the effects of this break on the development of caries and fluorosis in children. Study participants were continuously-resident children in Kindergarten through Grade 5 in Durham's elementary schools. There were 1696 children, 81.4% of those eligible, for whom a questionnaire was completed and clinical data recorded. Age cohorts were defined by a child's age at the time that fluoridation ceased. Caries was recorded in children in the Birth Cohort through Cohort 3, and fluorosis for children in Cohorts 1 through 5. Caries was assessed in the primary first and second molars according to the decayed-filled index; fluorosis on the labial surfaces of the upper permanent central and lateral incisors was assessed by the Thylstrup-Fejerskov (TF) index. Mother's education was associated with caries; higher education of the mother had an odds ratio of 0.53 (95% CI 0.40, 0.76) for caries in the child. No cohort effects could be discerned for caries. Overall prevalence of fluorosis was 44%. Prevalence in Cohorts 1, 2, 3, 4, and 5 was 39.8%, 32.3%, 33.0%, 62.3%, and 57.1%, respectively. These cohort differences remained statistically significant in regression analysis. It was concluded that while the break had little effect on caries, dental fluorosis is sensitive to even small changes in fluoride exposure from drinking water, and this sensitivity is greater at 1 to 3 years of age than at 4 or 5 years.

Assessing fluoride levels of carbonated soft drinks

BACKGROUND

Dental fluorosis occurs as a result of excessive total fluoride intake during tooth development. Some children may receive substantial intake from soft drinks, but few studies have reported fluoride levels in soft drinks. The authors examined the fluoride concentrations of 332 soft drinks.

METHODS

Soft drinks were purchased from Iowa grocery stores. To identify production sites, the authors recorded product details and batch numbers. After decarbonating the drinks, the authors assayed samples for fluoride content using a fluoride ion-specific electrode, and reported the results in parts per million, or ppm, using appropriate standards and duplicate assessments. Descriptive statistics were used to summarize the findings.

RESULTS

The fluoride levels of the products ranged from 0.02 to 1.28 ppm, with a mean level of 0.72 ppm. Fluoride levels exceeded 0.60 ppm for 71 percent of the products. Results varied substantially by production site, even within the same company and for the same product. There were no substantial differences between flavors or between diet and regular soft drinks.

CONCLUSIONS

The majority of soft drinks had fluoride levels exceeding 0.60 ppm. Variation in fluoride levels probably is due largely to the different water sources used in production.

CLINICAL IMPLICATIONS

With no fluoride levels marked on the soft drink products or easily available from the manufacturers, it is not possible for clinicians or consumers to directly estimate fluoride ingestion from carbonated beverages. Therefore, to reduce the risk of dental fluorosis, dental and medical practitioners should be cautious about prescribing dietary fluoride supplements to preschool-aged children in nonfluoridated areas who consume large quantities of carbonated soft drinks.

Fluoride intake from foods, beverages and dentifrice by young children in communities with negligibly and optimally fluoridated water: a pilot study

While the level of fluoride intake that affords optimal cariostatic efficacy without causing dental fluorosis is not precisely known, it has been suggested that the threshold of fluoride exposure above which fluorosis may occur is between 0.05 and 0.07 mg/kg/day.

OBJECTIVE

To monitor and compare fluoride intake from diet and dentifrice use (theoretical F: 0.10-0.11%) by three groups of 16- to 40-month-old children: two groups living in the negligibly water-fluoridated communities of San Juan, Puerto Rico, and Connersville, Indiana, and the third group residing in the optimally water-fluoridated region of Indianapolis, Indiana.

METHODS

Fluoride intake from diet was monitored by the "duplicate plate" method, and fluoride ingested from dentifrice was determined by subtracting the amount of fluoride recovered after brushing from the amount originally placed on the child's toothbrush.

RESULTS

The mean combined amount of fluoride ingested daily by children living in the negligibly fluoridated communities was not significantly different from that ingested by children in the fluoridated community. The major component of fluoride ingested by children in the negligibly fluoridated communities came from fluoridated dentifrice, and in the fluoridated area children ingested as much fluoride from toothpaste as they did from beverages. In San Juan mean daily fluoride intake was within the estimated range for safe fluoride exposure; however, in the "halo" community of Connersville and in Indianapolis, daily fluoride ingested by many of the children may have exceeded this level.

CONCLUSION

Attention needs to be given, in negligibly water-fluoridated as well as in optimally water-fluoridated communities, to reducing the daily intake of fluoride by young children in order to avoid putting them at risk of developing dental fluorosis.

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.

Dental fluorosis in 12-15-year-old rural children exposed to fluorides from well drinking water in the Hail region of Saudi Arabia

To investigate the relationship between fluoride levels in well drinking water, severity of dental fluorosis and dental caries in the Hail region of Saudi Arabia, 2355 rural children aged 12-15 years were examined. Over 90% of the children had fluorosed teeth and chi-square tests showed a strong association (P < 0.001) between fluoride level (0.5-2.8 ppm) in well drinking water and severity of dental fluorosis. Although regression analysis showed a statistically significant relationship (P < 0.001) between fluoride concentration and caries experience, the amount of variation explained was very low (R2 = 0.9%). Since fluoride in well water had little influence on caries experience and is causing dental fluorosis, it should be removed by defluoridation or the rural population should be provided with an alternative source of drinking water with lower fluoride concentration.

Using the DMF gender difference to assess the "major" role of fluoride toothpastes in the caries decline in industrialized countries: a meta-analysis

The regular use of fluoridated toothpastes has been ascribed a major role in the observed decline in caries prevalence in industrialized countries during the last 20 to 25 years, but only indirect evidence supports this claim. The purpose of this study was to test the hypothesis that the more frequent use of fluoride toothpastes by girls than by boys has reduced the relative age-specific D(M)FT gender difference, and that this difference should decrease with increasing age and fluoride toothpaste exposure among adolescents. The material comprised 8,777 subjects 12 to 17 years of age from the pre-fluoride toothpaste era (1946-1959) and 39,903 from the period when use of fluoride toothpaste had become common (1983-1993) in industrialized countries. Meta-analyses were done using the relative age-specific mean D(M)FT difference between girls and boys. Separate analyses were carried out for subgroups of studies/countries to check for confounding. Regardless of analytical approach, no evidence was found to support the hypothesis. It is concluded that the gender difference in fluoride exposure due to tooth brushing frequency is too small to matter, that the study lacked power, or that the role of fluoride toothpastes in the caries decline has been overrated.

Assessing fluoride concentrations of juices and juice-flavored drinks

Few studies have investigated fluoride exposures from juices and juice-flavored drinks manufactured with water. In this study, the authors analyzed 532 juices and juice drinks for fluoride. Fluoride ion concentrations ranged from 0.02 to 2.80 parts per million, in part because of variations in fluoride concentrations of water used in production. Children's ingestion of fluoride from juices and juice-flavored drinks can be substantial and a factor in the development of fluorosis.

Prevalence of dental fluorosis in Sudanese children from two villages with 0.25 and 2.56 ppm fluoride in the drinking water

Dental fluorosis is endemic in Eastern Africa and a high prevalence has been found even in low-fluoride (approximately 0.5 ppm) areas. Substantial seasonal changes in the fluoride content of water have also been reported. The aim of the present study was to ascertain, through one year, the fluoride concentration in water from two underground reservoirs in Sudan, in Treit el Biga (TeB) and Abu Groon (AG), and to assess dental fluorosis in children aged 7-16 years who had been lifelong residents. The water in one of the reservoirs (TeB) was shown to have a low, very stable fluoride concentration (0.25 ppm SD 0.04) whereas the other (AG) had a tenfold higher, and slightly varying, fluoride concentration (2.56 ppm SD 0.26). Dental fluorosis was recorded on maxillary central incisors according to Dean's index. In TeB 91% of the children showed signs of dental fluorosis whereas in AG all children had fluorotic teeth. The Community Fluorosis Index in TeB and AG was 1.40 and 2.44, respectively. There was a significantly higher degree of fluorosis in boys than in girls in the low-fluoride area. In TeB, older boys tended to have more fluorosis than younger boys; the difference, however, was not statistically significant. No significant sex or age differences in fluorosis were found in AG. In both villages great inter-individual variations in dental fluorosis were recorded. The prevalence and severity of dental fluorosis in TeB was higher than that previously reported in areas with similar fluoride concentrations in the drinking water.

Infants' fluoride ingestion from water, supplements and dentifrice

Concerns about dental fluorosis and the paucity of detailed fluoride intake data prompted this longitudinal study of fluoride intake in infants from birth to 9 months of age. On average, water fluoride intake greatly exceeded that from dietary fluoride supplements or fluoride dentifrice. However, fluoride supplements and dentifrice contributed substantial proportions of fluoride intake among children using them. Some children had estimated fluoride intake from water, supplements and dentifrice that exceeded the recommended "optimal" intake (a level that has yet to be determined scientifically). Practitioners should estimate fluoride ingestion from all these sources if considering systemic fluoride supplementation.

Infants' fluoride intake from drinking water alone, and from water added to formula, beverages, and food

In infants, the majority of total ingested fluoride is obtained from water, formula and beverages prepared with water, baby foods, and dietary fluoride supplements. Few studies have investigated the distribution of fluoride intake from these sources among young children at risk for dental fluorosis. The purpose of this study was to assess estimated water fluoride intake from different sources of water among a birth cohort studied longitudinally from birth until age 9 months. Parental reports were collected at 6 weeks, 3 months, 6 months, and 9 months of age for water, formula, beverage, and other dietary intake during the preceding week. Fluoride levels of home and child-care tap and bottled water sources were determined. This report estimates daily quantities of fluoride ingested only from water--both by itself and used to reconstitute formula, beverages, and food. Daily fluoride intake from water by itself ranged to 0.43 mg, with mean intakes < 0.05 mg. Water fluoride intake from reconstitution of concentrated infant formula ranged to 1.57 mg, with mean intakes by age from 0.18 to 0.31 mg. Fluoride intake from water added to juices and other beverages ranged to 0.67 mg, with means < 0.05 mg. Estimated total daily water fluoride intake ranged to 1.73 mg fluoride, with means from 0.29 to 0.38 mg.

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.

Fluoride supplements: current effectiveness, side effects, and recommendations

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 1990s, 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.

Water fluoridation: current effectiveness and dental fluorosis

This paper reviewed the literature on the evidence for water fluoridation's effectiveness under current conditions of multiple fluoride use at recommended and at reduced concentrations, the extent of dental fluorosis at different fluoride concentrations, and the "halo" effect of water fluoridation. Using the relative difference in dental caries between communities with low and optimal water fluoride as an indicator, the effectiveness of water fluoridation has decreased over time as the use of other fluorides has increased. Thus the effectiveness of water fluoridation alone cannot now be determined. Compared to the early fluoridation studies, the differences in dental caries and fluorosis prevalence between fluoridated and non-fluoridated areas have markedly narrowed. Both the prevalence and severity of dental fluorosis have increased since 1945; however, the portion of fluorosis due to water fluoridation is now less (40%) than that attributed to other fluoride sources (60%). Research also suggests that the "halo" effect of community water fluoridation may result in a significantly greater intake of fluoride for people in non-fluoridated communities. This review recognized that since water fluoridation has unique advantages from the perspectives of distribution, equity, compliance and cost-effectiveness over other fluoride technologies, it remains as the fundamental base for caries prevention. The increasingly greater contribution that other sources of fluoride make to dental fluorosis suggests that these sources of fluoride, many of which are used on an elective basis, should be more closely examined for needed changes.

Should the drinking water of Truro, Nova Scotia, be fluoridated? Water fluoridation in the 1990s

An epidemiological assessment of differences in caries and fluorosis prevalences between children in Truro (< 0.1 ppm) and Kentville (fluoridated at 1.1 ppm in 1991), Nova Scotia, Canada, was completed in 1991. Out of a total of 429 children, in grades 5 and 6, in the two towns in 1991, 219 (51%) were examined. Parents answered a self-administered questionnaire investigating the sources of drinking water used by the children since birth, residence history, use of fluoride supplements, dentifrices, and other fluoride products during the first 6 yr of the life. The examination criteria differentiated between non-cavitated and cavitated carious lesions. Dental fluorosis was measured using the TSIF index. Examiner agreement was excellent. Of the children examined, 80 (36.5%) drank water (fluoridated or non-fluoridated) from municipal water systems during the first 6 yr of life. The children were assigned into five groups based upon residence history and exposure to fluoridated water during the first 6 yr of life. The percentage difference in mean DMFS scores between children in the fluoridated and non-fluoridated groups is 17% (delta DMFS1 = 0.7) when non-cavitated carious lesions are included and 39% (delta DMFS2 = 1.1) when they are excluded. The differences are not statistically significant. The significant risk factors associated with the DMFS1 and DMFS2 scores identified by a stepwise multiple regression analysis are: education level of the father, gender, and number of years of reported use of toothpaste during the first 6 yr of life. Dental fluorosis (mainly TSIF score of 1) was present in 41.5% and 69.2% of the children in the non-fluoridated and fluoridated groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)