Fluoride Intake Levels in Relation to Fluorosis Development in Permanent Maxillary Central Incisors and First Molars

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.

Clinical and Forensic Signs Resulting from Exposure to Heavy Metals and Other Chemical Elements of the Periodic Table

Several heavy metals and other chemical elements are natural components of the Earth’s crust and their properties and toxicity have been recognized for thousands of years. Moreover, their use in industries presents a major source of environmental and occupational pollution. Therefore, this ubiquity in daily life may result in several potential exposures coming from natural sources (e.g., through food and water contamination), industrial processes, and commercial products, among others. The toxicity of most chemical elements of the periodic table accrues from their highly reactive nature, resulting in the formation of complexes with intracellular compounds that impair cellular pathways, leading to dysfunction, necrosis, and apoptosis. Nervous, gastrointestinal, hematopoietic, renal, and dermatological systems are the main targets. This manuscript aims to collect the clinical and forensic signs related to poisoning from heavy metals, such as thallium, lead, copper, mercury, iron, cadmium, and bismuth, as well as other chemical elements such as arsenic, selenium, and fluorine. Furthermore, their main sources of occupational and environmental exposure are highlighted in this review. The importance of rapid recognition is related to the fact that, through a high degree of suspicion, the clinician could rapidly initiate treatment even before the toxicological results are available, which can make a huge difference in these patients’ outcomes.

Analyzing dental fluorosis data using a novel Bayesian model for clustered longitudinal ordinal outcomes with an inflated category

We propose a Bayesian hurdle mixed-effects model to analyze longitudinal ordinal data under a complex multilevel structure. This research was motivated by the dataset gathered from the Iowa Fluoride Study (IFS) in order to establish the relationships between fluorosis status and potential risk/protective factors. Dental fluorosis is characterized by spots on tooth enamel and is due to ingestion of excessive fluoride intake during enamel formation. Observations are collected from multiple surface zones on each tooth and on all available teeth of children from the studied cohort, which are longitudinally observed at ages 9, 13, and 17. The data not only exhibit a complex hierarchical structure, but also have a large proportion of zero values that are likely to follow different statistical patterns from non-zero categories. Therefore, we develop a hurdle model to consider the zero category separately, while a proportional odds model is used for the positive categories. The estimated parameters are obtained from a Gibbs sampler implemented by the OpenBUGS software. Our model is compared with two popular methods for ordinal data: the proportional odds model and the partial proportional odds model. We perform a comprehensive analysis of the IFS data and evaluate the accuracy and effectiveness of our methodology through simulation studies. Our discoveries provide novel insights to statisticians and dental practitioners about the associations between patient and clinical characteristics and dental fluorosis.

Remineralizing Potential of Low-fluoridated, Nonfluoridated and Herbal Nonfluoridated Dentifrices on Demineralized Surface of Primary Teeth: An In Vitro Study

Aim

The aim of this in vitro study is to evaluate the remineralizing potential of commercially available low-fluoridated, nonfluoridated, and herbal nonfluoridated child formula dentifrices on primary teeth.

Materials and methods

Total of 36 primary teeth were placed in the demineralizing solution for 96 hours to produce artificial carious lesions of approximately 100 μm depth, and then cut longitudinally into 30 sections of 100–150 μm thickness and randomly assigned to three groups. Sections were treated with low-fluoridated, nonfluoridated, and herbal nonfluoridated dentifrice. Lesions were evaluated using polarized light microscopy.

Results

Intragroup comparison of mean lesion depth from pretreatment to posttreatment among the three study groups revealed that maximum reduction in lesion depth was found to be in group I (low-fluoridated) followed in descending order by group III (herbal nonfluoridated) and group II (nonfluoridated), respectively.

Conclusion

Group I (low-fluoridated) and group III (herbal nonfluoridated) demonstrated remineralization of carious lesions by virtue of a decrease in lesion depth, whereas group II (nonfluoridated) showed an increase in lesion depth.

Clinical significance

Fluoride dentifrices are the most widely used products that deliver topical fluoride to the oral environment. The major drawback is the risk of dental fluorosis, which occurs because of ingestion of dentifrices, in preschool children. This necessitates use of preventive measures which include (1) reducing the amount of toothpaste used, (2) supervised brushing in preschool children and (3) developing low-fluoride toothpastes for minimizing risk of dental fluorosis. Further dental professionals must investigate effectiveness of increasingly popular “Herbal” products.

How to cite this article

Tiwari S, Saha S, Dhinsa K, et al. Remineralizing Potential of Low-fluoridated, Nonfluoridated and Herbal Nonfluoridated Dentifrices on Demineralized Surface of Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(3):251-257.

Assessing Fluorosis Incidence in Areas with Low Fluoride Content in the Drinking Water, Fluorotic Enamel Architecture, and Composition Alterations

There is currently no consensus among researchers on the optimal level of fluoride for human growth and health. As drinking water is not the sole source of fluoride for humans, and fluoride can be found in many food sources, this work aimed to determine the incidence and severity of dental fluorosis in Poland, in areas where a low fluoride content characterizes the drinking water, and to assess the impact of fluoride on the enamel composition and microstructure. The dental examination involved 696 patients (aged 15−25 years) who had since birth lived in areas where the fluoride concentration in drinking water did not exceed 0.25 mg/L. The severity of the condition was evaluated using the Dean’s Index. Both healthy teeth and teeth with varying degrees of fluorosis underwent laboratory tests designed to assess the total protein and fluoride content of the enamel. Protein amount was assessed spectrophotometrically while the level of fluoride ions was measured by DX-120 ion chromatography. The clinical study revealed 89 cases (12.8%) of dental fluorosis of varying severity. The enamel of teeth with mild and moderate fluorosis contained a significantly higher protein (p-value < 0.001 and 0.002, respectively) and fluoride level (p < 0.001) than those with no clinical signs of fluorosis. SEM images showed irregularities in the structure of the fluorotic enamel. An excessive fluoride level during amelogenesis leads to adverse changes in the chemical composition of tooth enamel and its structure. Moreover, dental fluorosis present in areas where drinking water is low in fluorides indicates a need to monitor the supply of fluoride from other possible sources, regardless of its content in the water.

Review of Professionally Applied Fluorides for Preventing Dental Caries in Children and Adolescents

This review aims to evaluate the effectiveness of professional topical fluoride application on the prevention of dental caries in primary and permanent dentition. A web search was conducted for English papers published from 2000 to 2020, using various digital resources (Pubmed, Google Scholar, Cochrane Library, and ResearchGate). The keywords were “professionally applied fluoride”, “fluoride gel”, “fluoride varnish”, “fluoride foam”, “fluoride mouthrinses”, and “non-cavitated caries lesions”. Inclusion criteria: (a) participants: children and adolescents, treated in a dental care setting; (b) intervention: professionally applied fluorides (gel, varnish, foam, mouthrinse); (c) comparator: no professional treatment or other preventive treatments; (d) outcomes: clinical effectiveness (e.g., caries reduction, tooth remineralization); (e) study design: randomized controlled trials, systematic reviews, meta-analyses; (f) publication period: 1 January 2000–31 December 2021. Clinical studies about home-use fluoride products, discussion papers, in-vitro studies, case reports, non-English articles, and studies with unclear methodology were excluded. Topical fluoride applications are indicated for patients with active smooth surface caries and for patients in high caries risk groups. Both APF gel and fluoride varnish are effective and can be recommended for caries prevention in primary and permanent teeth. For children under the age of 6, only 2.26% fluoride varnish is recommended.

Exogenous Intake of Fluorides in Caries Prevention: Benefits and Risks

Caries incidence and prevalence have decreased significantly over the last few decades due to widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported in both fluoridated and non-fluoridated communities. Care must be taken to ensure that a balance between the optimal fluoride preventive effect at the individual and community level and minimal risk of dental fluorosis is maintained. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, dietary fluoride supplement, and topical forms comprising toothpastes, rinses, gels and varnishes. The cited data were taken from meta-analytic studies and reports from Cochrane database systematic reviews up to December 2019. Efficiency, but safety, of topically applied fluorides in individual home care is dependent on the degree of compliance of individuals/parents and on the level of competence of providers of preventive counselling. The broad spectrum of these resources allows individualization of fluoride prevention based on risk analysis of caries attack and taking into consideration other preventive measures.

Relationships between parental education, choice of child dentifrice, and their children's caries experience

BACKGROUND

The influence of parental education, choice of child dentifrice, and its impact on their children's dental caries experience remain unclear.

AIM

To investigate (a) dentifrice types used by Australian pre-school children, (b) demographic factors that influence parents' dentifrice choice, and (c) whether dentifrice type is related to pre-schooler's caries experience.

DESIGN

155 parent-child dyads were recruited from five random metropolitan childcare centres. Parents completed a questionnaire recording relevant demographics and child dietary preferences, oral hygiene practice, and dental visits. One calibrated operator performed a clinical examination of their pre-schooler for evidence of carious lesions. Data were analysed, and comparisons between variables made using chi-square tests and regression models.

RESULTS

50% of pre-schoolers used <1000 ppm fluoride dentifrice and 29% used non-fluoridated dentifrice. Higher parental education level was associated with the use of non-fluoridated dentifrice (P = .02, χ²  = 0.034). Children with higher brushing frequency were more likely to use fluoridated dentifrice (P = .03, χ²  < 0.001).

CONCLUSION

The proportion of Australian pre-schoolers using non-fluoridated dentifrice was higher than in other world regions. Higher parental education level was strongly associated with choosing non-fluoridated toothpaste, which warrants further qualitative analysis to assess determinants for parents' choice of child dentifrice.

Guidelines on the use of fluoride for caries prevention in children: an updated EAPD policy document

AIM

To update the exisitng European Academy of Paediatric Dentistry (EAPD) 2009 fluoride guidelines.

METHODS

Experts met in Athens, Greece duirng November 2018 for the following groups: I Fluoride toothpastes, II Fluoride gels, rinses and varnishes, III Fluoridated milk, fluoridated salt, tablets/lozenges and drops, IV Water fluoridation. Systematic reviews and meta-analyses were reviewed and discussed for each of the groups. The GRADE system was used to assess the quality of evidence which was judged as HIGH, MODERATE, LOW or VERY LOW based on the assessment of eight criteria which can influence the confidence of the results. Following the quality assessment, GRADE was then used to indicate the strength of recommendation for each fluoride agent as STRONG or WEAK/CONDITIONAL.

RESULTS

Parents must be strongly advised to apply an age-related amount of toothpaste and assist/supervise tooth brushing until at least 7 years of age. The EAPD strongly endorses the daily use of fluoride as a major part of any comprehensive programme for the prevention and control of dental caries in children. Regardless of the type of programme, community or individually based, the use of fluoride must be balanced between the estimation of caries-risk and the possible risks of adverse effects of the fluorides. Fluoride use is considered safe when the manufacturer's instructions are followed. Preventive programmes should be re-evaluated at regular intervals and adapted to a patient's or population's needs and risks.

CONCLUSIONS

For the majority of European Countries, the EAPD recommends the appropriate use of fluoride toothpaste in conjunction with good oral hygiene to be the basic fluoride regimen.

Review of Fluoride Intake and Appropriateness of Current Guidelines

Since the classical epidemiological studies by Dean, it has been known that there should be an optimum level of exposure to fluoride that would be able to provide the maximum protection against caries, with minimum dental fluorosis. The "optimal" daily intake of fluoride for children (0.05-0.07 mg per kilogram bodyweight) that is still accepted worldwide was empirically determined. In the present review, we discuss the appropriateness of the current guidance for fluoride intake, in light of the windows of susceptibility to caries and fluorosis, the modern trends of fluoride intake from multiple sources, individual variations in fluoride metabolism, and recent epidemiological data. The main conclusion is that it is very difficult to think about a strict recommendation for an "optimal" range of fluoride intake at the individual level in light of existing knowledge of 1) the mechanisms of action of fluoride to control caries, 2) the mechanisms involved in dental fluorosis development, 3) the distinct factors that interfere in the metabolism of fluoride, and 4) the windows of susceptibility to both dental caries and fluorosis development. An "optimal" range of fluoride intake is, however, desirable at the population level to guide programs of community fluoridation, but further research is necessary to provide additional support for future decisions on guidance in this area. This list includes the effect of factors affecting fluoride metabolism, clinical trials on the effectiveness of low-fluoride dentifrices to prevent caries in the primary dentition, and validation of biomarkers of exposure to fluoride.

Fluoride Revolution and Dental Caries: Evolution of Policies for Global Use

Epidemiological studies over 70 y ago provided the basis for the use of fluoride in caries prevention. They revealed the clear relation between water fluoride concentration, and therefore fluoride exposure, and prevalence and severity of dental fluorosis and dental caries. After successful trials, programs for water fluoridation were introduced, and industry developed effective fluoride-containing toothpastes and other fluoride vehicles. Reductions in caries experience were recorded in many countries, attributable to the widespread use of fluoride. This is a considerable success story; oral health for many was radically improved. While previously, water had been the only significant source of fluoride, now there are many, and this led to an increase in the occurrence of dental fluorosis. Risks identified for dental fluorosis were ingestion of fluoride-containing toothpaste, water fluoridation, fluoride tablets (which were sometimes ingested in areas with water fluoridation), and infant formula feeds. Policies were introduced to reduce excessive fluoride exposure during the period of tooth development, and these were successful in reducing dental fluorosis without compromising caries prevention. There is now a much better understanding of the public perception of dental fluorosis, with mild fluorosis being of no aesthetic concern. The advantages of water fluoridation are that it provides substantial lifelong caries prevention, is economic, and reduces health inequalities: it reaches a substantial number of people worldwide. Fluoride-containing toothpastes are by far the most important way of delivering the beneficial effect of fluoride worldwide. The preventive effects of conjoint exposure (e.g., use of fluoride toothpaste in a fluoridated area) are additive. The World Health Organization has informed member states of the benefits of the appropriate use of fluoride. Many countries have policies to maximize the benefits of fluoride, but many have yet to do so.

A comparison of dental fluorosis in adult populations with and without lifetime exposure to water fluoridation

OBJECTIVES

There is a lack of evidence on the proportion and severity of fluorosis in adult populations exposed and not exposed to fluoridated water over their lifetimes. The aim of this study was to compare the proportion and severity of fluorosis in adults with lifetime exposure to water fluoridation with a nonexposed sample. A secondary aim was to report the gradient of fluorosis severity by age.

METHODS

A cross-sectional study recruited a sample with lifetime exposure to water fluoridation and a matched, nonexposed group. 580 participants, aged 18-52 years (mean 34.3, SD 9.4) and 64% female, were recruited in general dental practices located in fluoridated (Birmingham and County Durham) and nonfluoridated areas (Manchester). Three digital images were taken of their incisors and an experienced examiner who was blind to exposure status viewed the images remotely and allocated fluorosis scores using the Thylstrup and Fejerskov (TF) scale.

RESULTS

At TF ≥ 1 (any fluorosis), a significantly higher proportion of participants from the fluoridated area had fluorosis (F 39% NF 21.3%, P < 0.001), at the threshold TF ≥ 3 ("aesthetic concern"), the difference was no longer statistically significant (F 4.1%, NF 2.2%, P = 0.25). There was a gradient by age, whereby fluorosis was highest in the youngest and lowest in the oldest age group.

CONCLUSIONS

Although fluorosis is more common in adults with lifetime exposure to water fluoridation than those with no exposure, the aesthetic impact of fluorosis seems to diminish with age.

Understanding Optimum Fluoride Intake from Population-Level Evidence

Policy on fluoride intake involves balancing caries against dental fluorosis in populations. The origin of this balance lies with Dean’s research on fluoride concentration in water supplies, caries, and fluorosis. Dean identified cut points in the Index of Dental Fluorosis of 0.4 and 0.6 as critical. These equate to 1.3 and 1.6 mg fluoride (F)/L. However, 1.0 mg F/L, initially called a permissible level, was adopted for fluoridation programs. McClure, in 1943, derived an “optimum” fluoride intake based on this permissible concentration. It was not until 1944 that Dean referred to this concentration as the “optimal” concentration. These were critical steps that have informed health authorities through to today. Several countries have derived toxicological estimates of an adequate and an upper level of intake of fluoride as an important nutrient. The US Institute of Medicine (IOM) in 1997 estimated an Adequate Intake (AI) of 0.05 mg F/kg bodyweight (bw)/d and a Tolerable Upper Intake Level (UL) of 0.10 mg F/kg bw/d. These have been widely promulgated. However, a conundrum has existed with estimates of actual fluoride intake that exceed the UL without the expected adverse fluorosis effects being observed. Both the AI and UL need review. Fluoride intake at an individual level should be interpreted to inform more nuanced guidelines for individual behavior. An “optimum” intake should be based on community perceptions of caries and fluorosis, while the ultimate test for fluoride intake is monitoring caries and fluorosis in populations.

A randomised controlled trial to measure the effects and costs of a dental caries prevention regime for young children attending primary care dental services: the Northern Ireland Caries Prevention In Practice (NIC-PIP) trial

BACKGROUND

Dental caries is the most common disease of childhood. The NHS guidelines promote preventative care in dental practices, particularly for young children. However, the cost-effectiveness of this policy has not been established.

OBJECTIVE

To measure the effects and costs of a composite fluoride intervention designed to prevent caries in young children attending dental services.

DESIGN

The study was a two-arm, parallel-group, randomised controlled trial, with an allocation ratio of 1 : 1. Randomisation was by clinical trials unit, using randomised permuted blocks. Children/families were not blinded; however, outcome assessment was blinded to group assessment.

SETTING

The study took place in 22 NHS dental practices in Northern Ireland, UK.

PARTICIPANTS

The study participants were children aged 2-3 years, who were caries free at baseline.

INTERVENTIONS

The intervention was composite in nature, comprising a varnish containing 22,600 parts per million (p.p.m.) fluoride, a toothbrush and a 50-ml tube of toothpaste containing 1450 p.p.m. fluoride; plus standardised, evidence-based prevention advice provided at 6-monthly intervals over 3 years. The control group received the prevention advice alone.

MAIN OUTCOME MEASURES

The primary outcome measure was conversion from caries-free to caries-active states. Secondary outcome measures were the number of decayed, missing or filled tooth surfaces in primary dentition (dmfs) in caries-active children, the number of episodes of pain, the number of extracted teeth and the costs of care. Adverse reactions (ARs) were recorded.

RESULTS

A total of 1248 children (624 randomised to each group) were recruited and 1096 (549 in the intervention group and 547 in the control group) were included in the final analyses. A total of 87% of the intervention children and 85% of control children attended every 6-month visit (p = 0.77). In total, 187 (34%) children in the intervention group converted to caries active, compared with 213 (39%) in the control group [odds ratio (OR) 0.81, 95% confidence interval (CI) 0.64 to 1.04; p = 0.11]. The mean number of tooth surfaces affected by caries was 7.2 in the intervention group, compared with 9.6 in the control group (p = 0.007). There was no significant difference in the number of episodes of pain between groups (p = 0.81). However, 164 out of the total of 400 (41%) children who converted to caries active reported toothache, compared with 62 out of 696 (9%) caries-free children (OR 7.1 95% CI 5.1 to 9.9; p < 0.001). There was no statistically significant difference in the number of teeth extracted in caries-active children (p = 0.95). Ten children in the intervention group had ARs of a minor nature. The average direct dental care cost was £155.74 for the intervention group and £48.21 for the control group over 3 years (p < 0.05). The mean cost per carious surface avoided over the 3 years was estimated at £251.00.

LIMITATIONS

The usual limitations of a trial such as generalisability and understanding the underlying reasons for the outcomes apply. There is no mean willingness-to-pay threshold available to enable assessment of value for money.

CONCLUSIONS

A statistically significant effect could not be demonstrated for the primary outcome. Once caries develop, pain is likely. There was a statistically significant difference in dmfs in caries-active children in favour of the intervention. Although adequately powered, the effect size of the intervention was small and of questionable clinical and economic benefit.

FUTURE WORK

Future work should assess the caries prevention effects of interventions to reduce sugar consumption at the population and individual levels. Interventions designed to arrest the disease once it is established need to be developed and tested in practice.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN36180119 and EudraCT 2009-010725-39.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 71. See the NIHR Journals Library website for further project information.

The relationships between fluoride intake levels and fluorosis of late-erupting permanent teeth

OBJECTIVES

To examine the relationships between fluoride intake levels and fluorosis of late-erupting permanent teeth.

METHODS

The current study used information collected from 437 children in the longitudinal Iowa Fluoride Study. Participants' fluoride intake information was collected using questionnaires from birth to age 10 years. Estimated mean daily fluoride intake was categorized into low, moderate, and high intake tertiles for each age interval (2-5, 5-8, and 2-8 years). Bivariate analyses were performed to study the relationships between self-reported fluoride intake levels during three age intervals and dental fluorosis.

RESULTS

For canines and second molars, the prevalence of mostly mild fluorosis was less than 10% in the lowest fluoride intake tertile and more than 25% in the highest intake tertile. For both first and second premolars, the prevalence in the low and high intake tertiles was approximately 10-15% and 25-40%, respectively. When estimated total daily fluoride intake was 0.04 mg/kg BW during ages 2-8 years, the predicted probability of fluorosis was 16.0%, 20.5%, 21.8%, and 15.4% for canines, 1st and 2nd and premolars and 2nd molars, respectively. We found that an incremental increase in fluoride intake during the age 5- to 8-year interval led to greater odds for development of mostly mild dental fluorosis in late-erupting teeth compared to increases in fluoride intake during other age intervals.

CONCLUSIONS

Our results clearly show that dental fluorosis prevalence is closely related to fluoride intake levels and that teeth have greater susceptibility to fluoride intake during certain age intervals.

Recommendations for fluoride limits in drinking water based on estimated daily fluoride intake in the Upper East Region, Ghana

Both dental and skeletal fluorosis caused by high fluoride intake are serious public health concerns around the world. Fluorosis is particularly pronounced in developing countries where elevated concentrations of naturally occurring fluoride are present in the drinking water, which is the primary route of exposure. The World Health Organization recommended limit of fluoride in drinking water is 1.5 mg F(-) L(-1), which is also the upper limit for fluoride in drinking water for several other countries such as Canada, China, India, Australia, and the European Union. In the United States the enforceable limit is much higher at 4 mg F(-) L(-1), which is intended to prevent severe skeletal fluorosis but does not protect against dental fluorosis. Many countries, including the United States, also have notably lower unenforced recommended limits to protect against dental fluorosis. One consideration in determining the optimum fluoride concentration in drinking water is daily water intake, which can be high in hot climates such as in northern Ghana. The results of this study show that average water intake is about two times higher in Ghana than in more temperate climates and, as a result, the fluoride intake is higher. The results also indicate that to protect the Ghanaian population against dental fluorosis, the maximum concentration of fluoride in drinking water for children under 6-8 years should be 0.6 mg F(-) L(-1) (and lower in the first two years of life), and the limit for older children and adults should be 1.0 mg F(-) L(-1). However, when considering that water treatment is not cost-free, the most widely recommended limit of 1.5 mg F(-) L(-1) - which is currently the limit in Ghana--may be appropriate for older children and adults since they are not vulnerable to dental fluorosis once the tooth enamel is formed.

Timing of fluoride intake and dental fluorosis on late-erupting permanent teeth

OBJECTIVE

Very few studies have examined the relationship between timing of fluoride intake and development of dental fluorosis on late-erupting permanent teeth using period-specific fluoride intake information. This study examined this relationship using longitudinal fluoride intake information from the Iowa Fluoride Study.

METHODS

Participants' fluoride exposure and intake (birth to 10 years of age) from water, beverages, selected food products, dietary fluoride supplements, and fluoride toothpaste was collected using questionnaires sent to parents at 3- and 4- month intervals from birth to 48 months of age and every 6 months thereafter. Three trained and calibrated examiners used the Fluorosis Risk Index (FRI) categories to assess 16 late-erupting teeth among 465 study participants. A tooth was defined as having definitive fluorosis if any of the zones on that tooth had an FRI score of 2 or 3. Participants with questionable fluorosis were excluded from analyses. Descriptive and logistic regression analyses were performed to assess the importance of fluoride intake during different time periods.

RESULTS

Most dental fluorosis in the study population was mild, with only four subjects (1%) having severe fluorosis (FRI Score 3). The overall prevalence of dental fluorosis was 27.8%. Logistic regression analyses showed that fluoride intake from each of the individual years from age 2 to 8 plays an important role in determining the risk of dental fluorosis for most late-erupting permanent teeth. The strongest association for fluorosis on the late-erupting permanent teeth was with fluoride intake during the sixth year of life.

CONCLUSION

Late-erupting teeth may be susceptible to fluorosis for an extended period from about age 2 to 8. Although not as visually prominent as the maxillary central incisors, some of the late-erupting teeth are esthetically important and this should be taken into consideration when making recommendations about dosing of fluoride intake.

The association between social deprivation and the prevalence and severity of dental caries and fluorosis in populations with and without water fluoridation

BACKGROUND

To determine the association between social deprivation and the prevalence of caries (including caries lesions restricted to enamel) and enamel fluorosis in areas that are served by either fluoridated or non-fluoridated drinking water using clinical scoring, remote blinded, photographic scoring for caries and fluorosis. The study also aimed to explore the use of remote, blinded methodologies to minimize the effect of examiner bias.

METHODS

Subjects were male and female lifetime residents aged 11-13 years. Clinical assessments of caries and fluorosis were performed on permanent teeth using ICDAS and blind scoring of standardized photographs of maxillary central incisors using TF Index (with cases for fluorosis defined as TF > 0).

RESULTS

Data from 1783 subjects were available (910 Newcastle, 873 Manchester). Levels of material deprivation (Index of Multiple Deprivation) were comparable for both populations (Newcastle mean 35.22, range 2.77-78.85; Manchester mean 37.04, range 1.84-84.02). Subjects in the fluoridated population had significantly less caries experience than the non-fluoridated population when assessed by clinical scores or photographic scores across all quintiles of deprivation for white spot lesions: Newcastle mean DMFT 2.94 (clinical); 2.51 (photo), Manchester mean DMFT 4.48 (clinical); 3.44 (photo) and caries into dentine (Newcastle Mean DMFT 0.65 (clinical); 0.58 (photo), Manchester mean DMFT 1.07 (clinical); 0.98 (photo). The only exception being for the least deprived quintile for caries into dentine where there were no significant differences between the cities: Newcastle mean DMFT 0.38 (clinical); 0.36 (photo), Manchester mean DMFT 0.45 (clinical); 0.39 (photo). The odds ratio for white spot caries experience (or worse) in Manchester was 1.9 relative to Newcastle. The odds ratio for caries into dentine in Manchester was 1.8 relative to Newcastle. The odds ratio for developing fluorosis in Newcastle was 3.3 relative to Manchester.

CONCLUSIONS

Water fluoridation appears to reduce the social class gradient between deprivation and caries experience when considering caries into dentine. However, this was associated with an increased risk of developing mild fluorosis. The use of intra-oral cameras and remote scoring of photographs for caries demonstrated good potential for blinded scoring.

Enamel pits in hamster molars, formed by a single high fluoride dose, are associated with a perturbation of transitional stage ameloblasts

Excessive intake of fluoride (F) by young children results in the formation of enamel subsurface porosities and pits, called enamel fluorosis. In this study, we used a single high dose of F administered to hamster pups to determine the stage of ameloblasts most affected by F and whether pit formation was related to F-related sub-ameloblastic cyst formation. Hamster pups received a single subcutaneous injection of either 20 mg or 40 mg NaF/kg body weight, were sacrificed 24 h later, and the number of cysts formed in the first molars were counted. Other pups were sacrificed 8 days after F injection, when the first molars had just erupted, to score for enamel defects. All F-injected pups formed enamel defects in the upper half of the cusps in a dose-dependent way. After injection of 20 mg NaF/kg, an average of 2.5 white spots per molar was found but no pits. At 40 mg NaF/kg, almost 4.5 spots per molar were counted as well as 2 pits per molar. The defects in erupted enamel were located in the upper half of the cusps, sites where cysts had formed at the transition stage of ameloblast differentiation. These results suggest that transitional ameloblasts, located between secretory- and maturation-stage ameloblasts, are most sensitive to the effects of a single high dose of F. F-induced cysts formed earlier at the pre-secretory stage were not correlated to either white spots or enamel pits, suggesting that damaged ameloblasts overlying a F-induced cyst regenerate and continue to form enamel.

Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - paper 2: the ability of fluorescence imaging to detect differences in fluorosis prevalence and severity for different fluoride intakes from water

Background

To assess the ability of fluorescence imaging to detect a dose response relationship between fluorosis severity and different levels of fluoride in water supplies compared to remote photographic scoring in selected populations participating in an observational, epidemiological survey in Chiang Mai, Thailand.

Methods

Subjects were male and female lifetime residents aged 8-13 years. For each child the fluoride content of cooking water samples (CWS) was assessed to create categorical intervals of water fluoride concentration. Fluorescence images were taken of the maxillary central incisors and analyzed for dental fluorosis using two different software techniques. Output metrics for the fluorescence imaging techniques were compared to TF scores from blinded photographic scores obtained from the survey.

Results

Data from 553 subjects were available. Both software analysis techniques demonstrated significant correlations with the photographic scores. The metrics for area effected by fluorosis and the overall fluorescence loss had the strongest association with the photographic TF score (Spearman’s rho 0.664 and 0.652 respectively). Both software techniques performed well for comparison of repeat fluorescence images with ICC values of 0.95 and 0.85 respectively.

Conclusions

This study supports the potential use of fluorescence imaging for the objective quantification of dental fluorosis. Fluorescence imaging was able to discriminate between populations with different fluoride exposures on a comparable level to remote photographic scoring with acceptable levels of repeatability.

Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation

Background

To determine the severity of dental fluorosis in selected populations in Chiang Mai, Thailand with different exposures to fluoride and to explore possible risk indicators for dental fluorosis.

Methods

Subjects were male and female lifetime residents aged 8–13 years. For each child the fluoride content of drinking and cooking water samples were assessed. Digital images were taken of the maxillary central incisors for later blind scoring for TF index (10% repeat scores). Interview data explored previous cooking and drinking water use, exposure to fluoride, infant feeding patterns and oral hygiene practices.

Results

Data from 560 subjects were available for analysis (298 M, 262 F). A weighted kappa of 0.80 was obtained for repeat photographic scores. The prevalence of fluorosis (TF 3+) for subjects consuming drinking and cooking water with a fluoride concentration of <0.9 ppm was 10.2%. For subjects consuming drinking and cooking water >0.9 ppm F the prevalence of fluorosis (TF 3+) rose to 37.3%. Drinking and cooking water at age 3, water used for infant formula and water used for preparing infant food all demonstrated an increase in fluorosis severity with increase in water fluoride level (p < 0.001). The probability estimate for the presentation of aesthetically significant fluorosis was 0.53 for exposure to high fluoride drinking (≥0.9 ppm) and cooking water (≥1.6 ppm).

Conclusions

The consumption of drinking water with fluoride content >0.9 ppm and use of cooking water with fluoride content >1.6 ppm were associated with an increased risk of aesthetically significant dental fluorosis. Fluoride levels in the current drinking and cooking water sources were strongly correlated with fluorosis severity. Further work is needed to explore fluorosis risk in relation to total fluoride intake from all sources including food preparation.

Validation of fingernail fluoride concentration as a predictor of risk for dental fluorosis

The aim of this study was to validate the use of fingernail fluoride concentrations at ages 2-7 years as predictors of the risk for developing dental fluorosis in the permanent dentition. Fifty-six children of both genders (10-15 years of age) had their incisors and premolars examined for dental fluorosis using the Thylstrup-Fejerskov index. Fingernail fluoride concentrations were obtained from previous studies when children were 2-7 years of age. Data were analyzed by unpaired t test, ANOVA, and Fisher's exact test when the fingernail fluoride concentrations were dichotomized (≤ 2 or >2 µg/g). Children with dental fluorosis had significantly higher fingernail fluoride concentrations than those without the condition, and the concentrations tended to increase with the severity of fluorosis (r(2) = 0.47, p < 0.0001). Using a fingernail fluoride concentration of 2 µg/g at ages 2-7 years as a threshold, this biomarker had high sensitivity (0.84) and moderate specificity (0.53) as a predictor for dental fluorosis. The high positive predictive value indicates that fingernail fluoride concentrations should be useful in public health research, since it has the potential to identify around 80% of children at risk of developing dental fluorosis.

Quantitative light fluorescence (QLF) and polarized white light (PWL) assessments of dental fluorosis in an epidemiological setting

Background

To determine if a novel dual camera imaging system employing both polarized white light (PWL) and quantitative light induced fluorescence imaging (QLF) is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods.

Methods

Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3) participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF) Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software.

Results

Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s) between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92.

Conclusions

The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

Fluoride

Fluoride is a naturally occurring element with multiple implications for human health. This review discusses its metabolism and toxicity, along with the current understanding of the mechanism of action of fluoride and its role as a safe and effective agent in the prevention of dental caries. The relationship between excessive fluoride intake during periods of dental enamel formation and the development of dental fluorosis is also reviewed.

Association between socioeconomic factors and the choice of dentifrice and fluoride intake by children

It is questionable whether socioeconomic factors influence the choice of marketed children’s dentifrices and whether these products are associated with greater fluoride (F) intake in children. The present cross-sectional study involving 197 children (mean age: 40.98 ± 6.62 months) was carried out in Montes Claros, Brazil. Parents completed a questionnaire on socioeconomic status and the tooth brushing habits of their children. The children brushed their teeth and saliva residues were collected for F analysis. F intake from dentifrice was determined with an ion-specific electrode. Univariate analysis and logistic regression were used to test whether the type of dentifrice (children’s or family) and F dose (<0.05 and ≥0.05 mg F/Kg of body weight/day) were associated with the independent variables (p < 0.05). No differences were found between children’s and family dentifrices regarding daily F intake (0.046 and 0.040 mg F/Kg/day, respectively; p = 0.513). The following were strong predictors for the use of a children’s dentifrice: studying at a private kindergarten (OR: 6.89; p < 0.001); age that the child begun to tooth brush <2 years (OR: 2.93; p = 0.041), and the interaction between the variables “use of the same dentifrice as parents” and “type of tooth brush used” (OR: 27.20; p < 0.001). “The amount of dentifrice used” and “frequency of tooth brushing” (p ≤ 0.004) had a statistically and synergistic effect over the daily F dose. The present study found a social influence over the choice of dentifrice: children with a high socioeconomic status tend to use a children’s dentifrice. The amount of dentifrice used can strongly increase the risk of exposure to higher doses of F, regardless of the type of dentifrice.

Protocol for Northern Ireland Caries Prevention in Practice Trial (NIC-PIP) trial: a randomised controlled trial to measure the effects and costs of a dental caries prevention regime for young children attending primary care dental services

BACKGROUND

Dental caries is a persistent public health problem with little change in the prevalence in young children over the last 20 years. Once a child contracts the disease it has a significant impact on their quality of life. There is good evidence from Cochrane reviews including trials that fluoride varnish and regular use of fluoride toothpaste can prevent caries. The Northern Ireland Caries Prevention in Practice Trial (NIC-PIP) trial will compare the costs and effects of a caries preventive package (fluoride varnish, toothpaste, toothbrush and standardised dental health education) with dental health education alone in young children.

METHODS/DESIGN

A randomised controlled trial on children initially aged 2 and 3 years old who are regular attenders at the primary dental care services in Northern Ireland. Children will be recruited and randomised in dental practices. Children will be randomised to the prevention package of both fluoride varnish (twice per year for three years), fluoride toothpaste (1,450 ppm F) (supplied twice per year), a toothbrush (supplied twice a year) or not; both test and control groups receive standardised dental health education delivered by the dentist twice per year. Randomisation will be conducted by the Belfast Trust Clinical Research Support Centre ([CRSC] a Clinical Trials Unit). 1200 participants will be recruited from approximately 40 dental practices. Children will be examined for caries by independent dental examiners at baseline and will be excluded if they have caries. The independent dental examiners will examine the children again at 3 years blinded to study group.The primary end-point is whether the child develops caries (cavitation into dentine) or not over the three years. One secondary outcome is the number of carious surfaces in the primary dentition in children who experience caries. Other secondary outcomes are episodes of pain, extraction of primary teeth, other adverse events and costs which will be obtained from parental questionnaires.

DISCUSSION

This is a pragmatic trial conducted in general dental practice. It tests a composite caries prevention intervention, which represents an evidence based approach advocated by current guidance from the English Department of Health which is feasible to deliver to all low risk (caries free) children in general dental practice. The trial will provide valuable information to policy makers and clinicians on the costs and effects of caries prevention delivered to young children in general dental practice.

TRIAL REGISTRATION

EudraCT No: 2009 - 010725 - 39 ISRCTN: ISRCTN36180119 Ethics Reference No: 09/H1008/93:

Evidence-based clinical recommendations regarding fluoride intake from reconstituted infant formula and enamel fluorosis: a report of the American Dental Association Council on Scientific Affairs

BACKGROUND

This article presents evidence-based clinical recommendations regarding the intake of fluoride from reconstituted infant formula and its potential association with enamel fluorosis. The recommendations were developed by an expert panel convened by the American Dental Association (ADA) Council on Scientific Affairs (CSA). The panel addressed the following question: Is consumption of infant formula reconstituted with water that contains various concentrations of fluoride by infants from birth to age 12 months associated with an increased risk of developing enamel fluorosis in the permanent dentition?

TYPES OF STUDIES REVIEWED

A panel of experts convened by the ADA CSA, in collaboration with staff of the ADA Center for Evidence-based Dentistry (CEBD), conducted a MEDLINE search to identify systematic reviews and clinical studies published since the systematic reviews were conducted that addressed the review question.

RESULTS

CEBD staff identified one systematic review and two clinical studies. The panel reviewed this evidence to develop recommendations.

CLINICAL IMPLICATIONS

The panel suggested that when dentists advise parents and caregivers of infants who consume powdered or liquid concentrate infant formula as the main source of nutrition, they can suggest the continued use of powdered or liquid concentrate infant formulas reconstituted with optimally fluoridated drinking water while being cognizant of the potential risks of enamel fluorosis development. These recommendations are presented as a resource to be considered in the clinical decision-making process. As part of the evidence-based approach to care, these clinical recommendations should be integrated with the practitioner's professional judgment and the patient's needs and preferences.

Fluoride content of water used to reconstitute infant formula

OBJECTIVE

To assess the fluoride content of water used to reconstitute infant formula by a Latino population living in the Indianapolis, Indiana, area.

BACKGROUND

Negligible as well as excessive fluoride can be detrimental to oral health. Estimates of fluoride intake and exposure for individuals may aid in the determination of their risk for developing dental fluorosis or caries.

METHODS

Interviews were conducted to determine brands of bottled water used to reconstitute infant formula. Identified brands were analyzed for fluoride concentration.

RESULTS

Of the 458 samples tested (from 20 brands), fluoride concentration ranged from 0.006 to 0.740 μg/mL. All brands but one had fluoride concentration less than 0.7 μg/mL, with 16 brands having less than 0.22 μg/mL. Most bottled waters analyzed in the study comply with the American Dental Association recommendation to prevent fluorosis. Comparisons made demonstrated that only waters targeted for infants and that are fluoridated do not comply with recent American Dental Association recommendations.

Fate of fluoride-induced subameloblastic cysts in developing hamster molar tooth germs

White opacities and pits are developmental defects in enamel caused by high intake of fluoride (F) during amelogenesis. We tested the hypothesis that these enamel pits develop at locations where F induces the formation of sub-ameloblastic cysts. We followed the fate of these cysts during molar development over time. Mandibles from hamster pups injected with 20mg NaF/kg at postnatal day 4 were excised from 1h after injection till shortly after tooth eruption, 8 days later. Tissues were histologically processed and cysts located and measured. Cysts were formed at early secretory stage and transitional stage of amelogenesis and detected as early 1h after injection. The number of cysts increased from 1 to almost 4 per molar during the first 16h post-injection. The size of the cysts was about the same, i.e., 0.46±0.29×10(6)μm(3) at 2h and 0.50±0.35×10(7)μm(3) at 16h post-injection. By detachment of the ameloblasts the forming enamel surface below the cyst was cell-free for the first 16h post-injection. With time new ameloblasts repopulated and covered the enamel surface in the cystic area. Three days after injection all cysts had disappeared and the integrity of the ameloblastic layer restored. After eruption, white opaque areas with intact enamel surface were found occlusally at similar anatomical locations as late secretory stage cysts were seen pre-eruptively. We conclude that at this moderate F dose, the opaque sub-surface defects with intact surface enamel (white spots) are the consequence of the fluoride-induced cystic lesions formed earlier under the late secretory-transitional stage ameloblasts.

How much toothpaste should a child under the age of 6 years use?

AIM

To discuss current concepts in the use of fluoride and to determine how much fluoride is sufficient for caries prevention but also how much is too much. Use of fluoride by young children is a balance between maximising caries efficacy and minimising the risk of fluorosis.

METHODS

Review of the current literature. This review considers the importance of amount, concentration and dose of fluoride applied from toothpaste and the implications for risk and benefit.

RESULTS

Dental fluorosis is dependent on local fluoride levels in the extra cellular fluid surrounding the tooth during its development. These fluoride levels are determined by the plasma concentration that in turn is a function of the daily intake of fluoride. Fluoride released from bone during remodelling may also contribute to fluoride levels in the tissue. There is evidence to suggest that the effects of fluoride resulting in fluorosis prior to eruption of the tooth are cumulative and dependent on the amount and duration of exposure rather than a specific window of vulnerability. In contrast to dilution of ingested fluoride in the large volume of plasma, dilution of toothpaste in oral fluids is relatively small. Hence, for a given dose of fluoride, higher fluoride levels can be achieved in the oral environment using small amounts of toothpaste with higher fluoride concentrations rather than larger amounts with lower fluoride concentrations.

CONCLUSION

It is concluded that for young children fluoride ingestion needs to be carefully controlled during the first six years of life and the best balance between risk and efficacy might be achieved by using small amounts of high fluoride toothpaste under close supervision from parents.

Topical fluoride as a cause of dental fluorosis in children

BACKGROUND

For many years, topical use of fluorides has gained greater popularity than systemic use of fluorides. A possible adverse effect associated with the use of topical fluoride is the development of dental fluorosis due to the ingestion of excessive fluoride by young children with developing teeth.

OBJECTIVES

To describe the relationship between the use of topical fluorides in young children and the risk of developing dental fluorosis.

SEARCH STRATEGY

Electronic search of the Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE, EMBASE, BIOSIS, Dissertation Abstracts and LILACS/BBO. Reference lists from relevant articles were searched. Date of the most recent searches: 9th March 09.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs, cohort studies, case-control studies and cross-sectional surveys, in which fluoride toothpastes, mouthrinses, gels, foams, paint-on solutions, and varnishes were compared to an alternative fluoride treatment, placebo or no intervention group. Children under the age of 6 years at the time topical fluorides were used.

DATA COLLECTION AND ANALYSIS

Data from all included studies were extracted by two review authors. Risk ratios for controlled, prospective studies and odds ratios for case-control studies or cross-sectional surveys were extracted or calculated. Where both adjusted and unadjusted risk ratios or odds ratios were presented, the adjusted value was included in the meta-analysis.

MAIN RESULTS

25 studies were included: 2 RCTs, 1 cohort study, 6 case-control studies and 16 cross-sectional surveys. Only one RCT was judged to be at low risk of bias. The other RCT and all observational studies were judged to be at moderate to high risk of bias. Studies were included in four intervention/exposure comparisons. A statistically significant reduction in fluorosis was found if brushing of a child's teeth with fluoride toothpaste commenced after the age of 12 months odds ratio 0.70 (random-effects: 95% confidence interval 0.57 to 0.88) (data from observational studies). Inconsistent statistically significant associations were found between starting using fluoride toothpaste/toothbrushing before or after the age of 24 months and fluorosis (data from observational studies). From the RCTs, use of higher level of fluoride was associated with an increased risk of fluorosis. No significant association between the frequency of toothbrushing or the amount of fluoride toothpaste used and fluorosis was found.

AUTHORS' CONCLUSIONS

There should be a balanced consideration between the benefits of topical fluorides in caries prevention and the risk of the development of fluorosis. Most of the available evidence focuses on mild fluorosis. There is weak unreliable evidence that starting the use of fluoride toothpaste in children under 12 months of age may be associated with an increased risk of fluorosis. The evidence for its use between the age of 12 and 24 months is equivocal. If the risk of fluorosis is of concern, the fluoride level of toothpaste for young children (under 6 years of age) is recommended to be lower than 1000 parts per million (ppm).More evidence with low risk of bias is needed. Future trials assessing the effectiveness of different types of topical fluorides (including toothpastes, gels, varnishes and mouthrinses) or different concentrations or both should ensure that they include an adequate follow-up period in order to collect data on potential fluorosis. As it is unethical to propose RCTs to assess fluorosis itself, it is acknowledged that further observational studies will be undertaken in this area. However, attention needs to be given to the choice of study design, bearing in mind that prospective, controlled studies will be less susceptible to bias than retrospective and/or uncontrolled studies.

The impact of fluoride on ameloblasts and the mechanisms of enamel fluorosis

Intake of excess amounts of fluoride during tooth development cause enamel fluorosis, a developmental disturbance that makes enamel more porous. In mild fluorosis, there are white opaque striations across the enamel surface, whereas in more severe cases, the porous regions increase in size, with enamel pitting, and secondary discoloration of the enamel surface. The effects of fluoride on enamel formation suggest that fluoride affects the enamel-forming cells, the ameloblasts. Studies investigating the effects of fluoride on ameloblasts and the mechanisms of fluorosis are based on in vitro cultures as well as animal models. The use of these model systems requires a biologically relevant fluoride dose, and must be carefully interpreted in relation to human tooth formation. Based on these studies, we propose that fluoride can directly affect the ameloblasts, particularly at high fluoride levels, while at lower fluoride levels, the ameloblasts may respond to local effects of fluoride on the mineralizing matrix. A new working model is presented, focused on the assumption that fluoride increases the rate of mineral formation, resulting in a greater release of protons into the forming enamel matrix.

Fluoride ingestion from food items and dentifrice in 2-6-year-old Brazilian children living in a fluoridated area using a semiquantitative food frequency questionnaire

OBJECTIVES

The aim of this study was to evaluate the fluoride intake of 2-6-year-old Brazilian children using a semiquantitative food frequency questionnaire (FFQ) which also estimated fluoride intake from dentifrice.

METHODS

The FFQ was previously validated through application to 78 2-6-year-old Brazilian children and then administered to 379 children residing in an optimally fluoridated community in Brazil (Bauru, State of São Paulo). The FFQ was applied to the parents and used to estimate the food intake of the children. The constituents of the diet were divided into solids, water and other beverages. The fluoride content of the diet items was analyzed with the fluoride electrode. The questionnaire also estimated fluoride intake from dentifrice.

RESULTS

The average (+/-SD) fluoride intake from solids, water, other beverages and dentifrice was 0.008 +/- 0.005; 0.011 +/- 0.004; 0.009 +/- 0.014 and 0.036 +/- 0.028 mg F/kg body weight/day, respectively, totalizing 0.064 +/- 0.035 mg F/kg body weight/day. The dentifrice and the diet contributed with 56.3% and 43.7% of the daily fluoride intake, respectively. Among the children evaluated, 31.2% are estimated to have risk to develop dental fluorosis (intake>0.07 mg F/kg body weight/day).

CONCLUSIONS

The dentifrice was the main source of fluoride intake by the children evaluated. However, the fluoride concentration in food items also significantly contributed to the daily ingestion by 2-6-year-old children. The questionnaire used seems to be a promising alternative to duplicate diet to estimate the fluoride intake at this age range and may have potential to be used in broad epidemiological surveys.

Comparison of a dietary survey and the duplicate plate method for determining dietary fluoride ingested by young children: a pilot study

BACKGROUND

Investigators have attempted to establish the diet's contribution to the total body burden of fluoride in response to a reported trend towards an increase in fluoride intake.

AIM

The aim of this study was to compare the suitability of two methods to collect dietary data for fluoride intake assessment.

DESIGN

Assessments were made in 12 children using the duplicate plate and dietary diary methods following a randomized cross-over design. Foods and beverages were analysed for fluoride, and total fluoride intake per day was calculated. Results from each method were compared.

RESULTS

Mean beverage fluoride intake was estimated at 316 +/- 120 and 422 +/- 195 microg/day utilizing the diary and duplicate plate methods, respectively. Mean food fluoride intake was estimated at 188 +/- 48 microg/day using the diary, whereas it was 130 +/- 41 microg using the duplicate plate method. Total fluoride intake was 504 +/- 138 and 552 +/- 192 microg/day utilizing the diary and duplicate methods. Large variations in daily fluoride intake from both beverages and food were observed between and within children.

CONCLUSIONS

Both methods had inherent shortcomings and sources of error. The duplicate method was more labour intensive and costly; however, the diary method required a large number of assumptions. A combination of both methods seems to be most suitable to obtain reliable data.

Prospective study of the association between fluoride intake and dental fluorosis in permanent teeth

OBJECTIVE

To evaluate the relationship between fluoride intake and dental fluorosis in permanent central incisors and first molars.

METHODS

Fluoride intake (mg F/kg body weight/day) from diet, dentifrice and both combined was determined on a single occasion in 1998 among children aged 19-39 months living in two fluoridated Brazilian communities (0.6-0.8 ppm F). Six years later, when the permanent teeth of these children had erupted (central incisors and first molars), 49 children aged 7-9 years [20 girls (40.8%) and 29 boys (58.2%)] were evaluated for dental fluorosis. To test the association between fluorosis and fluoride intake, children were dichotomized into two groups, cases (children with dental fluorosis on at least two teeth, TFI > or =1) and noncases (children without dental fluorosis, TFI = 0).

RESULTS

Among the case group (n = 29), median fluoride doses from diet, dentifrice and combined were 0.031, 0.050 and 0.083 mg F/kg/day, respectively. Among the noncase group (n = 20), median fluoride doses were 0.029, 0.049, 0.084 mg F/kg/day, respectively. There was no association between dental fluorosis in permanent teeth and fluoride intake from diet, dentifrice and combined (p > 0.05).

CONCLUSIONS

There was no difference between children with and without fluorosis in the permanent central incisors and first molars regarding fluoride intake. However, this study has limitations that must be recognized: fluoride intake was only measured once, and there were no children in the sample with severe degrees of dental fluorosis.

Aesthetic management of severely fluorosed incisors in an adolescent female

BACKGROUND

Dental fluorosis is a condition of enamel hypomineralization due to the effects of excessive fluoride on ameloblasts during enamel formation. Delayed degradation of enamel matrix proteins or inhibited protein removal results in impaired and incomplete crystal growth, producing hypomineralized and porous enamel. Severely fluorosed teeth may undergo post-eruptive surface breakdown and post-eruptive dark brown to black staining.

METHODS

A 13 year old girl presented with severely discoloured maxillary central incisors. Initial aesthetic management of these teeth was conservative, including in-office tooth whitening, microabrasion and take-home whitening.

RESULTS

Dark brown to black staining of the teeth was reduced successfully without the need for gross mechanical preparation of the enamel. Further improvement of aesthetics was achieved with composite veneers.

CONCLUSIONS

Conservative treatment options such as tooth whitening and microabrasion can dramatically improve severely discoloured fluorosed teeth. This can provide a satisfactory interim outcome or minimize the removal of discoloured enamel and dentine prior to the provision of composite veneers. The use of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) may enhance remineralization and decrease postoperative sensitivity following tooth whitening and microabrasion procedures in hypomineralized teeth.