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

Topical fluoride as a cause of dental fluorosis in children

BACKGROUND

This is an update of a review first published in 2010. Use of topical fluoride has become more common over time. Excessive fluoride consumption from topical fluorides in young children could potentially lead to dental fluorosis in permanent teeth.

OBJECTIVES

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

SEARCH METHODS

We carried out electronic searches of the Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase, three other databases, and two trials registers. We searched the reference lists of relevant articles. The latest search date was 28 July 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), quasi-RCTs, cohort studies, case-control studies, and cross-sectional surveys comparing fluoride toothpaste, mouth rinses, gels, foams, paint-on solutions, and varnishes to a different fluoride therapy, placebo, or no intervention. Upon the introduction of topical fluorides, the target population was children under six years of age.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and used GRADE to assess the certainty of the evidence. The primary outcome measure was the percentage prevalence of fluorosis in the permanent teeth. Two authors extracted data from all included studies. In cases where both adjusted and unadjusted risk ratios or odds ratios were reported, we used the adjusted value in the meta-analysis.

MAIN RESULTS

We included 43 studies: three RCTs, four cohort studies, 10 case-control studies, and 26 cross-sectional surveys. We judged all three RCTs, one cohort study, one case-control study, and six cross-sectional studies to have some concerns for risk of bias. We judged all other observational studies to be at high risk of bias. We grouped the studies into five comparisons. Comparison 1. Age at which children started toothbrushing with fluoride toothpaste Two cohort studies (260 children) provided very uncertain evidence regarding the association between children starting to use fluoride toothpaste for brushing at or before 12 months versus after 12 months and the development of fluorosis (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.81 to 1.18; very low-certainty evidence). Similarly, evidence from one cohort study (3939 children) and two cross-sectional studies (1484 children) provided very uncertain evidence regarding the association between children starting to use fluoride toothpaste for brushing before or after the age of 24 months (RR 0.83, 95% CI 0.61 to 1.13; very low-certainty evidence) or before or after four years (odds ratio (OR) 1.60, 95% CI 0.77 to 3.35; very low-certainty evidence), respectively. Comparison 2. Frequency of toothbrushing with fluoride toothpaste Two case-control studies (258 children) provided very uncertain evidence regarding the association between children brushing less than twice per day versus twice or more per day and the development of fluorosis (OR 1.63, 95% CI 0.81 to 3.28; very low-certainty evidence). Two cross-sectional surveys (1693 children) demonstrated that brushing less than once per day versus once or more per day may be associated with a decrease in the development of fluorosis in children (OR 0.62, 95% CI 0.53 to 0.74; low-certainty evidence). Comparison 3. Amount of fluoride toothpaste used for toothbrushing Two case-control studies (258 children) provided very uncertain evidence regarding the association between children using less than half a brush of toothpaste, versus half or more of the brush, and the development of fluorosis (OR 0.77, 95% CI 0.41 to 1.46; very low-certainty evidence). The evidence from cross-sectional surveys was also very uncertain (OR 0.92, 95% CI 0.66 to 1.28; 3 studies, 2037 children; very low-certainty evidence). Comparison 4. Fluoride concentration in toothpaste There was evidence from two RCTs (1968 children) that lower fluoride concentration in the toothpaste used by children under six years of age likely reduces the risk of developing fluorosis: 550 parts per million (ppm) fluoride versus 1000 ppm (RR 0.75, 95% CI 0.57 to 0.99; moderate-certainty evidence); 440 ppm fluoride versus 1450 ppm (RR 0.72, 95% CI 0.58 to 0.89; moderate-certainty evidence). The age at which the toothbrushing commenced was 24 months and 12 months, respectively. Two case-control studies (258 children) provided very uncertain evidence regarding the association between fluoride concentrations under 1000 ppm, versus concentrations of 1000 ppm or above, and the development of fluorosis (OR 0.89, 95% CI 0.52 to 1.52; very low-certainty evidence). Comparison 5. Age at which topical fluoride varnish was applied There was evidence from one RCT (123 children) that there may be little to no difference between a fluoride varnish application before four years, versus no application, and the development of fluorosis (RR 0.77, 95% CI 0.45 to 1.31; low-certainty evidence). There was low-certainty evidence from two cross-sectional surveys (982 children) that the application of topical fluoride varnish before four years of age may be associated with the development of fluorosis in children (OR 2.18, 95% CI 1.46 to 3.25).

AUTHORS' CONCLUSIONS

Most evidence identified mild fluorosis as a potential adverse outcome of using topical fluoride at an early age. There is low- to very low-certainty and inconclusive evidence on the risk of having fluorosis in permanent teeth for: when a child starts receiving topical fluoride varnish application; toothbrushing with fluoride toothpaste; the amount of toothpaste used by the child; and the frequency of toothbrushing. Moderate-certainty evidence from RCTs showed that children who brushed with 1000 ppm or more fluoride toothpaste from one to two years of age until five to six years of age probably had an increased chance of developing dental fluorosis in permanent teeth. It is unethical to propose new RCTs to assess the development of dental fluorosis. However, future RCTs focusing on dental caries prevention could record children's exposure to topical fluoride sources in early life and evaluate the dental fluorosis in their permanent teeth as a long-term outcome. In the absence of these studies and methods, further research in this area will come from observational studies. 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 uncontrolled studies.

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.

Treatment decisions regarding caries and dental developmental defects in children - a questionnaire-based study among Norwegian dentists

BACKGROUND

Current knowledge on treatment strategies and choice of restorative materials when treating deep caries or severe dental developmental defects (DDDs) in young individuals is scarce. Therefore, the aim was to investigate Norwegian dentists´ treatment decisions and reasons for treatment choice when treating deep caries in primary teeth and severe DDDs in permanent teeth in children.

METHODS

A pre-coded questionnaire was sent electronically to all dentists employed in the Public Dental Service (PDS) in Norway (n = 1294). The clinicians were asked about their background characteristics and how often they registered DDDs. Three clinical cases were presented to the dentists and asked to prioritize treatment options and reasons for their choice.

RESULTS

After three reminders, 45.8% of the dentists answered. Most clinicians were general practitioners (96.3%), females (77.9%), under 41 year-olds (59.4%), graduated in 2001 or later (61.1%), and representing all regions of Norway. The respondents registered molar incisor hypomineralisation (MIH), other DDDs and dental fluorosis (DF) frequently, 523 (91.1%), 257 (44.8%) and 158 (27.5%), respectively. In case 1a with severe dental caries in a primary molar, the preferred treatment was resin-modified glass ionomer cement (RMGIC) (58.3%), followed by glass ionomer cement (GIC) (17.9%) and zinc oxide-eugenol (ZOE) (13.2%). Extraction, compomer or stainless steel crowns (SSC) were preferred by 0.9, 0.7 and 0.4%, respectively. In case 1b, which was identical to case 1a, but treated under general anaesthesia, the preferred treatment alternatives were RMGIC (37.1%), resin composite (RC) (17.6%) and GIC (17.2%). Extraction and SSC were chosen by 15.1 and 7.2%, respectively. In case 2, showing a severely hypomineralised and symptomatic first permanent molar, the dentists preferred RC (38.4%), followed by RMGIC (26.6%) and GIC (19.0%). Extraction and SSC were chosen by 8.7 and 5.4%, respectively. The treatment choices were not significantly affected by the dentists' background characteristics. The reasons for dentists' treatment decisions varied for each patient case; patient cooperation, prognosis of the tooth and own experience were the dominant reasons.

CONCLUSIONS

A notable disparity in treatment choices was shown indicating that Norwegian dentists evaluate each case individually and base their decisions on what they consider best for the individual patient.

Toothpaste Utilization Profiles among Preschool Children

BACKGROUND

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

Preventing dental caries in children <5 years: systematic review updating USPSTF recommendation

BACKGROUND AND OBJECTIVE

Screening and preventive interventions by primary care providers could improve outcomes related to early childhood caries. The objective of this study was to update the 2004 US Preventive Services Task Force systematic review on prevention of caries in children younger than 5 years of age.

METHODS

Searching Medline and the Cochrane Library (through March 2013) and reference lists, we included trials and controlled observational studies on the effectiveness and harms of screening and treatments. One author extracted study characteristics and results, which were checked for accuracy by a second author. Two authors independently assessed study quality.

RESULTS

No study evaluated effects of screening by primary care providers on clinical outcomes. One good-quality cohort study found pediatrician examination associated with a sensitivity of 0.76 for identifying a child with cavities. No new trials evaluated oral fluoride supplementation. Three new randomized trials were consistent with previous studies in finding fluoride varnish more effective than no varnish (reduction in caries increment 18% to 59%). Three trials of xylitol were inconclusive regarding effects on caries. New observational studies were consistent with previous evidence showing an association between early childhood fluoride use and enamel fluorosis. Evidence on the accuracy of risk prediction instruments in primary care settings is not available.

CONCLUSIONS

There is no direct evidence that screening by primary care clinicians reduces early childhood caries. Evidence previously reviewed by the US Preventive Services Task Force found oral fluoride supplementation effective at reducing caries incidence, and new evidence supports the effectiveness of fluoride varnish in higher-risk children.

[Pregnant women living in areas of endemic fluorosis in Senegal and low birthweight newborns: case-control study]

BACKGROUND

In developing countries, maternal and neonatal mortality is high. Among the causes of death during the neonatal period, low birth weight is crucial. A dose of fluoride beyond 2mg/L causes enamel damage, possibly affecting the fetus. The aim of this study was to search for an association between dental fluorosis in the mother and low birthweight of the newborn.

METHODOLOGY

This was a case-control study performed in an endemic area in Senegal (Diourbel). It included 108 mothers who gave birth to newborns weighing less than 2500 g (cases) and 216 mothers with newborns weighing greater or equal to 2500 g (controls). Data on socio-demographic, lifestyle, history and pregnancy variables were collected. Those related to water consumption during pregnancy and dental fluorosis (Dean's index) were measured. The data were analyzed by R software. Logistic regression was used to identify associations and the statistical significance level was set to 0.05.

RESULTS

The proportions of mothers consuming well water were 62% among cases versus 43.5% among controls. The score 4 of Dean's Index was reported for 25.9% of cases versus 6.9% of controls. The water consumed and the modal score of Dean's Index were significantly associated with the occurrence of low birthweight adjusted for gender, consanguinity, anemia and hypertension.

CONCLUSION

Low birthweight was associated with pregnant women living in endemic areas. Defluoridation programs and access for pregnant women and children to high quality water are necessary in areas of endemic fluorosis.

Guidelines on the use of fluoride in children: an EAPD policy document

The EAPD strongly endorses that the daily use of fluoride should be a major part of any comprehensive preventive program for the control of dental caries in children. Regardless of the type of program, community or individually based, the suggested use of fluoride must be balanced between the estimation of caries risks and the possible risks for toxic effects of the fluorides. Such a preventive program should be re-evaluated at regular intervals and adapted to a patient's needs and risks. For the majority of European communities, the EAPD recommends the use of appropriate fluoride toothpaste in conjunction with good oral hygiene to be the basic fluoride regimen.

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.

Fluoride supplements, dental caries and fluorosis: a systematic review

BACKGROUND

In this review, the authors examine evidence regarding the effectiveness of fluoride supplements in preventing caries and their association with dental fluorosis.

METHODS

Using tested search filters, the authors searched MEDLINE, the Cochrane Central Register of Controlled Trials, OVID Evidence-based Reviews and EMBASE. The authors agreed on the inclusion of 20 reports from 12 trials that met defined criteria. They also included five studies published since 1997 regarding the association between dental fluorosis and supplements.

RESULTS

Eleven of the reports evaluated dosage schedules similar to that recommended by the American Dental Association. One potentially highly biased study of primary teeth of children during the first three years of life reported a 47.2 percent reduction in dental caries experience. Investigators in one trial involving 3- to 6-year-old children found a 43.0 percent difference, and another trial of children in this age group did not find a significant benefit. Researchers in several studies involving older children detected a significant reduction in caries increments in permanent teeth with the use of fluoride supplements. Fifteen of the studies had withdrawal rates of 30 percent or higher. All of the five included studies that evaluated the association between use of fluoride supplements and dental fluorosis found that use of the supplements increased the risk of mild-to-moderate fluorosis.

CONCLUSIONS

There is weak and inconsistent evidence that the use of fluoride supplements prevents dental caries in primary teeth. There is evidence that such supplements prevent caries in permanent teeth. Mild-to-moderate dental fluorosis is a significant side effect.

CLINICAL IMPLICATIONS

The current recommendations for use of fluoride supplements during the first six years of life should be re-examined.

[A socioeconomic classification and the discussion related to prevalence of dental caries and dental fluorosis]

OBJECTIVE

The aim of this study was to evaluate the relationship between a socioeconomic classification model and prevalence of dental caries and dental fluorosis in Piracicaba, Sâo Paulo, Brazil.

METHODS

For this classification five indicators were used (family monthly income, number of residents in the same household, parents' formal educational level, type of housing and occupation of person responsible for the family). A scoring system was used in order to arrange in a hierarchy, 812 12 year old school children distributed between six different social classes. Volunteers were examined in the school's back patio under natural light with a dental mirror, by two examiners calibrated for DMFT index (dental caries) and T-F (dental fluorosis). The qui-square test (p<0.01) was used in the statistical analysis for the association of DMFT and the dental fluorosis and between the socioeconomic variable and the proposed social classes.

RESULTS

The DMFT average was 1.7, while 31.4%, of the children had dental fluorosis (T-Fe"1).

CONCLUSION

With respect to socioeconomic class a statistically significant association was only verified with dental caries.

Prevalence of Dental Fluorosis in German Schoolchildren in Areas with Different Preventive Programmes

In a retrospective study in two different regions of Germany, 1,041 fifteen-year-old pupils were examined for dental fluorosis. The adolescents had taken part in different caries prevention programmes. There were 746 subjects in the study group and 295 subjects in the control group. For each participant, specific aspects of early development, diet and fluoride exposure in group prevention programmes and at home were determined by means of questionnaires. The Thylstrup-Fejerskov index was used to classify the fluorosis scores on the buccal surfaces of teeth 11, 12, 13, 14, 15 and 16 after compressed air drying of the teeth. Binary logistic stepwise regression analyses were conducted to identify associations between fluorosis and potential influence factors. A distinction was made between early and late developing tooth parts. The significance level was set at alpha = 0.05. Fluorosis prevalence in the regions studied was 7.1 and 11.3%, respectively. The difference was not statistically significant (p = 0.052; chi square). Binary logistic stepwise regression analysis revealed that 'early start of toothbrushing' was a statistically significant predictor of dental fluorosis in the early-mineralizing enamel (OR = 1.99, p = 0.027). For the late-mineralizing enamel no single independent variable was identified as a significant predictor of dental fluorosis.

Perception of dental fluorosis and other oral health disorders by 12-year-old Brazilian children

AIM

The aim of this study was to verify the perception of dental fluorosis as an oral health problem by 12-year-old Brazilian children and to evaluate if they were able to detect other oral disorders.

METHODOLOGY

The sample consisted of 401 schoolchildren. Firstly, clinical examinations were performed using a visual method under natural light. After that, children answered a questionnaire with the purpose of assessing the self-perception of their oral health problems. Next, the volunteers were shown a photo album containing 24 photographs, and had to match each photo with a severity scale.

RESULTS

The prevalence of fluorosis was 18.2%; 81.8% of this total in fluorosis scale T-F 1. Of the 401 children, 48.9% (n = 196) answered oral health problems related to concerns, such as aesthetic appearance or pain. Among them, only two children, both with fluorosis T-F 2, correlated their problems with the presence of stained teeth. As regards the photo album analysis, the children considered photos showing fluorosis T-F 7-9 as the most severe, whereas the photo of an orally healthy patient was considered the least severe.

CONCLUSION

Children did not show negative perception of dental fluorosis, except for dental fluorosis at severe levels (T-F 7-9), and were mainly able to detect aesthetic or pain-related problems.

Fluoride dentifrice ingestion and fluorosis of the permanent incisors

BACKGROUND

Fluoride dentifrice is a primary means of preventing childhood caries, but it is also an important risk factor for fluorosis. The authors examine the influence of fluoride dentifrice ingestion on fluorosis of the permanent incisors.

METHODS

Participants in the Iowa Fluoride Study received questionnaires at regular intervals concerning fluoride sources. The authors assessed fluorosis using the fluorosis risk index. They estimated daily fluoride ingestion from dentifrice, diet and fluoride supplements and divided the amount by kilograms of body weight. The statistical analysis related fluoride ingestion to fluorosis in the permanent incisors.

RESULTS

In bivariate analyses, mild fluorosis was significantly related to ingestion of fluoride dentifrice at ages 24 and 36 months (P = .02 for both). After the authors adjusted for fluoride ingested from dietary sources, logistic regression showed a significant association between fluorosis and dentifrice ingestion at age 24 months (P = .04).

CONCLUSIONS

The study results suggest that fluorosis of the permanent incisors is influenced by ingestion of fluoride dentifrice during the first three years of life. Further research is needed to assess total intake of fluoride as a risk factor for fluorosis.

CLINICAL IMPLICATIONS

These results support recommendations that young children use only a pea-sized amount of dentifrice. Parents should supervise young children as they brush their teeth with fluoride dentifrice.

The rational use of fluoride toothpaste

Well-formulated fluoride toothpastes are clinically proven to prevent and control dental caries. They may also be a risk factor in the aetiology of dental fluorosis. This review considers the available evidence to support the appropriate use of fluoride toothpaste to maximise the benefit and minimise the risk. Three factors have an important influence on the anticaries efficacy of fluoride toothpaste, namely concentration, frequency of brushing and post brushing rinsing behaviour. The evidence suggests that low-fluoride (<600 ppm F) toothpastes provide less caries protection than standard (1,000 ppm F) or high (1,500 ppm F) concentration formulations. However, low-fluoride toothpastes are appropriate for very young children (under 7 years) at low caries risk, particularly if living in fluoridated areas. For other young children, higher concentrations of fluoride should be used. Brushing should be recommended twice daily, whilst rinsing with large volumes of water should be discouraged. Small amounts of toothpaste are comparable in efficacy to large amounts. The risk of fluorosis is associated with the ingestion of high doses of fluoride during tooth development and consequently only young children are at risk. The variability in the dose of fluoride ingested is mainly a function of the amount used, less so its concentration. To minimise fluorosis risk, parents should be advised to use only a pea-sized amount of toothpaste and encourage spitting out of excess. It is concluded that by using fluoride toothpastes appropriately, the benefits can be maximised and the risks of fluorosis minimised.

A review of fluorosis in the European Union: prevalence, risk factors and aesthetic issues

Fluoride has played a key role in caries prevention for the past 50 years but excessive ingestion of fluoride during tooth development may lead to dental fluorosis. Throughout Europe many vehicles have been, and are currently, employed for optimal fluoride delivery including drinking water, toothpaste, fluoride supplements, salt and milk. Several indices, both descriptive and aetiological, have been developed and used for measuring fluorosis. This factor, combined with the lack of use of a standardized method for measurement of fluorosis, has made comparison between studies difficult and assessment of trends in fluorosis prevalence unreliable. Overall the evidence would appear to indicate, however, that diffuse enamel opacities are more prevalent in fluoridated than in nonfluoridated communities and that their prevalence at the very mild level may be increasing. In addition to fluoridated drinking water, risk factors for fluorosis include inadvertent ingestion of fluoride toothpaste and the inappropriate use of fluoride supplements. The risk is of aesthetic concern primarily during the period of enamel development of the permanent central incisors, although this largely appears to be a cosmetic rather than a public-health issue. It is concluded that there is a need to co-ordinate studies measuring fluorosis throughout Europe and that development of a standardized photographic method would be useful. Furthermore, the aesthetic importance of fluorosis needs to be determined in more detail in each country in the light of each country's respective risk factors and dental health policies.

[Dental fluorosis in Brazil: a critical review]

This paper discusses dental fluorosis as a relevant public health problem, using a review of epidemiological studies published in the last 10 years on the disease's prevalence, severity, and risk factors. The results suggest that there are already more cases than expected, although few studies refer to major severity. Thus, measures are needed for the prevention and surveillance of dental 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.

Dietary effects on dental diseases

Dental caries is a highly prevalent chronic disease and its consequences cause a lot of pain and suffering. Sugars, particularly sucrose, are the most important dietary aetiological cause of caries. Both the frequency of consumption and total amount of sugars is important in the aetiology of caries. The evidence establishing sugars as an aetiological factor in dental caries is overwhelming. The foundation of this lies in the multiplicity of studies rather than the power of any one. That statement by the British Nutrition Foundation's Task Force on Oral Health, Diet and Other Factors, sums up the relationship between sugars and caries in Europe. There is no evidence that sugars naturally incorporated in the cellular structure of foods (intrinsic sugars) or lactose in milk or milk products (milk sugars) have adverse effects on health. Foods rich in starch, without the addition of sugars, play a small role in coronal dental caries. The intake of extrinsic sugars beyond four times a day leads to an increase risk of dental caries. The current dose-response relationship between caries and extrinsic sugars suggests that the sugars levels above 60 g/person/day for teenagers and adults increases the rate of caries. For pre-school and young children the intakes should be proportional to those for teenagers; about 30 g/person/day for pre-school children. Fluoride, particularly in toothpastes, is a very important preventive agent against dental caries. Toothbrushing without fluorides has little effect on caries. As additional fluoride to that currently available in toothpaste does not appear to be benefiting the teeth of the majority of people, the main strategy to further reduce the levels of caries, is reducing the frequency of sugars intakes in the diet. Dental erosion rates are considered to be increasing. The aetiology is acids in foods and drinks and to a much lesser extent from regurgitation.

Low birth weight and dental fluorosis: is there an association?

OBJECTIVE

The association between low birth weight and dental fluorosis was explored in a cross-sectional study to explain the higher prevalence of dental fluorosis among African-American children.

METHODS

Birth weight data on 960 children were obtained from the New York State Birth Registry. Data on race, fluoride exposure, sociodemographic characteristics, and dental fluorosis were available from a cross-sectional study conducted in Newburgh and Kingston. Associations among birth weight, race, and fluoride exposure from fluoridated water, regular use of supplements, brushing before the age of 2 years, and subject-level dental fluorosis were explored using logistic regression procedures.

RESULTS

The regression coefficients for the main effects and the two-way interaction effects associated with low birth weight, race, and fluoride exposure were not statistically significant. Even after controlling for low birth weight and fluoride exposure, African-American children had a statistically significant higher odds ratio (OR = 2.0). An analysis of the data limited to mandibular permanent first molars showed similar effects, except for evidence of effect modification in low birth weight children exposed to fluoride supplements.

CONCLUSIONS

Lower birth weight did not explain the higher prevalence of dental fluorosis observed among African-American children.

Dental fluorosis in permanent incisor teeth in relation to water fluoridation, social deprivation and toothpaste use in infancy

OBJECTIVES

To determine the prevalence and severity of fluorosis in permanent incisor teeth in young children in a fluoridated and a fluoride-deficient community and to establish what relationship, if any, there was between the occurrence of dental fluorosis and the reported use of fluoride toothpaste in childhood.

DESIGN

A prevalence study of children aged 8-9 years who had been continuous residents in fluoridated Newcastle or fluoride-deficient Northumberland.

METHOD

The permanent maxillary central incisor teeth were examined clinically and photographically by one examiner using the Thylstrup-Fejerskov index; the photographs were read blind to child identity and clinical score. A closed-response questionnaire enquired into the child's early experiences of toothbrushing and use of fluoride toothpastes. Social deprivation was measured by a Jarman score. The study took place in 1998.

OUTCOME MEASURE

Prevalence of dental fluorosis measured by the Thylstrup-Fejerskov index.

RESULTS

Complete data were available for 78% (n = 409) and 79% (n = 403) of eligible sampled children in the two areas, respectively. Clinical and photographic results agreed closely and had high reproducibility. The prevalence of fluorosis was 54% in the fluoridated area and 23% in the fluoride-deficient area when all grades (> 0) of fluorosis were included; percentage prevalence of mild to moderate fluorosis (> or = 3) was 3% and 0.5% in the two areas, respectively. Multivariate analysis indicated that area of residence (odds ratio = 4.5), Jarman score (odds ratio = 0.99 per Jarman unit) and type of toothpaste (odds ratio = 1.6) were statistically significantly related to presence or absence of fluorosis: the risk factors were--fluoridated area, affluence, and use of adult toothpaste.

CONCLUSIONS AND RECOMMENDATIONS

The prevalence of aesthetically important dental fluorosis was low, although higher in the fluoridated area. Use of a child's toothpaste (with lower fluoride concentration) could decrease risk in a fluoridated area. Adherence to the guidelines published by the British Society of Paediatric Dentistry is recommended.

Risk of enamel fluorosis in nonfluoridated and optimally fluoridated populations: considerations for the dental professional

BACKGROUND

Few studies have evaluated the impact of specific fluoride sources on the prevalence of enamel fluorosis in the population. The author conducted research to determine attributable risk percent estimates for mild-to-moderate enamel fluorosis in two populations of middle-school-aged children.

METHODS

The author recruited two groups of children 10 to 14 years of age. One group of 429 had grown up in nonfluoridated communities; the other group of 234 had grown up in optimally fluoridated communities. Trained examiners measured enamel fluorosis using the Fluorosis Risk Index and measured early childhood fluoride exposure using a questionnaire completed by the parent. The author then calculated attributable risk percent estimates, or the proportion of cases of mild-to-moderate enamel fluorosis associated with exposure to specific early fluoride sources, based on logistic regression models.

RESULTS

In the nonfluoridated study sample, sixty-five percent of the enamel fluorosis cases were attributed to fluoride supplementation under the pre-1994 protocol. An additional 34 percent were explained by the children having brushed more than once per day during the first two years of life. In the optimally fluoridated study sample, 68 percent of the enamel fluorosis cases were explained by the children using more than a pea-sized amount of toothpaste during the first year of life, 13 percent by having been inappropriately given a fluoride supplement, and 9 percent by the use of infant formula in the form of a powdered concentrate.

CONCLUSIONS

Enamel fluorosis in the nonfluoridated study sample was attributed to fluoride supplementation under the pre-1994 protocol and early toothbrushing behaviors. Enamel fluorosis in the optimally fluoridated study sample was attributed to early toothbrushing behaviors, inappropriate fluoride supplementation and the use of infant formula in the form of a powdered concentrate.

CLINICAL IMPLICATIONS

By advising parents about the best early use of fluoride agents, health professionals play an important role in reducing the prevalence of clinically noticeable enamel fluorosis.

Dental fluorosis among persons exposed to high- and low-fluoride drinking water in western Norway

The aim of this project was to study the prevalence and severity of dental fluorosis among persons exposed to moderate- to high- or low-fluoride drinking water in western Norway, and to assess the risk factors involved. Subjects aged 5 to 18 years who had been lifelong consumers of moderate- to high-fluoride groundwater (> or = 0.50 mg F/L) were selected for the study (n = 113). A comparison group (n = 105) was chosen among consumers of low-fluoride surface water (approximately 0.10 mg F/L) in the same district. The Thylstrup-Fejerskov (TF) Index was used to score dental fluorosis. A questionnaire was used to obtain information on fluoride exposure and other relevant factors. Among the consumers of low-fluoride water 14.3% showed dental fluorosis (TF score 1-2) as compared to 78.8% in the group consuming moderate- to high-fluoride water (TF scores 1-7). Premolars were most frequently affected, but severe cases (TF scores 3-7) were equally prevalent in maxillary central incisors and first molars. In logistic regression analysis with TF score 0 or TF score > or = 1 as the dependent variable, only fluoride concentration in the drinking water was associated with a statistically increased risk of dental fluorosis (odds ratio: 18.9; 95% CI: 8.85-40.44). In the study area, which was characterised by multiple fluoride sources, uncontrolled groundwater with moderate to high fluoride content was the most important factor in the development of dental fluorosis. In order to prevent dental fluorosis, groundwater wells should routinely be analysed for fluoride.

Fluoride supplements and caries in a non-fluoridated child population

In Norway, there is no water fluoridation and little naturally occurring fluoride in drinking water. Fluoride toothpaste is used by 95% of the population and there is a long tradition of use of fluoride supplements. The purpose of this study was to analyse whether children who used fluoride toothpaste regularly and complied with the recommendations for use of fluoride supplements had less caries than other children at the age of 8 years. Most fluoride supplements sold in Norway are lozenge-type tablets, which allow for extended enamel exposure to fluoride. All children (n = 551) born in 1988 living in a suburban community in Norway were invited to participate. In those who participated (n = 470), caries was registered clinically and radiographically and parents provided data on use of supplements. Thirty-eight percent of the children had used fluoride supplements regularly during the period 0.5 to 4.0 years of age and 66% used supplements regularly at the age of 6 to 8 years. Multivariate analyses showed that the children complying with the recommendations for use of fluoride supplements during the period 0.5 to 4.0 years of age had lower caries experience (dmfs) and fewer decayed surfaces (ds) in primary teeth than other children. No significant associations were found between supplement use in childhood and caries prevalence (DMFS) or number of decayed surfaces (DS) in permanent teeth at the age of 8 years. Supplement use from 6 to 8 years of age was not associated with caries occurrence either in primary or in permanent teeth. Both mother's education and the quality of dental hygiene were inversely associated with caries occurrence.

Fluoride supplements for young children: an analysis of the literature focusing on benefits and risks

The use of fluoride supplements to prevent caries has been advised for more than 100 years, but serious promotion of this strategy occurred only after the effectiveness of water fluoridation was established, in the late 1950s and 1960s. Although the effectiveness of fluoride supplements was apparently endorsed by many small clinical studies, closer examination of the experimental conditions of these, their methods and the analysis of their results undermined confidence in their findings. It is likely that confounding resulted in spurious conclusions in many of them. More modern, well-conducted clinical trials of supplements suggest that today, in children also exposed to fluoride from other sources such as toothpaste, the marginal effect of fluoride supplements is very small. There is evidence that fluoride lozenges, designed to maximise any local effect, may have a small caries preventive effect, particularly in deciduous teeth. Overall, poor compliance makes fluoride supplements a poor public health measure. Supplement use by young children is associated with a substantial risk of dental fluorosis. Fluorosis is an issue about which the public is becoming concerned in several countries and this concern, if translated into opposition to all fluoride use, could jeopardise the most successful caries preventive aid we have. The potential for dental fluorosis, concern about the public's reaction to this, the poor effectiveness of supplements and the public's poor compliance with their use are persuasive arguments for a radical reduction in the use of supplements by young children. Recent changes in fluoride dosage schedules and deferment of the age of commencing the use of supplements, implemented in many countries, have followed from these concerns. Supplements formulated as lozenges maximise topical exposure of enamel to fluoride and such products may offer older children and some adults a way of maintaining an elevated fluoride level in saliva at times when toothbrushing is not practical.

Fluoride supplements and fluorosis: a meta-analysis

This paper presents a systematic review of the dental literature that was carried out to investigate whether the regular use of fluoride supplements in non-fluoridated communities during the period of tooth development increases the risk of dental fluorosis. A MEDLINE search was organized for all documents published, in English, between January 1966 and September 1997 using the following key words: fluorosis, dental, fluoride, fluoride supplement or supplements, drop or drops, and tablet or tablets. Twenty-four studies that assessed the development of dental fluorosis in children who had used fluoride supplements earlier in their life were included in this review. Of the 24 studies, 10 were cross-sectional/case control studies and four were follow-up studies. These studies had data that allowed a quantitative estimation of the risk of developing dental fluorosis in users of fluoride supplements. The other 10 studies were excluded because they either did not present enough data or had other methodological problems. A qualitative review of the studies found a consistent and strong association between the use of fluoride supplements and dental fluorosis. The meta-analyses of the cross-sectional/case-control studies estimated that the odds ratio of dental fluorosis in users of fluoride supplements compared with non-users ranged between 2.4 and 2.6. The meta-analyses of the follow-up studies estimated that the relative risk in long-term users was between 5.5 and 12.2. This review confirmed that in non-fluoridated communities the use of fluoride supplements during the first 6 years of life is associated with a significant increase in the risk of developing dental fluorosis.