Non-fluoridated Areas Research Articles

Community water fluoride cessation and rate of caries-related pediatric dental treatments under general anesthesia in Alberta, Canada.

This study examined the rate of caries-related dental treatments under general anesthesia (GA) in fluoridated and non-fluoridated communities in Alberta, Canada, between 2010 and 2019. This retrospective, population-based study included all children ( 12years of age) living in Calgary (non-fluoridated) and Edmonton (fluoridated) who underwent caries-related dental treatments under GA at publicly funded facilities. Demographics and dental data were extracted from health administrative databases for three time periods of 2010/11 (pre-cessation), 2014/15, and 2018/19 (post-cessation). Among 2659 children receiving caries-related treatments under GA, the mean (SD) and median (IQR) age were 4.8 (2.3) and 4 (3-6) years, respectively, and 65% resided in the non-fluoridated area. The analysis revealed that the cessation of water fluoridation was significantly associated with an increased rate of caries-related GA events per 10,000 children in both age groups (0-5 and 6-11years), with a more pronounced effect in 0-5-year-olds in non-fluoridated areas. The risk of dental treatments under GA was also positively associated with post-cessation time. Discontinuing water fluoridation appears to negatively affect young children's oral health, potentially leading to a significant increase in caries-related dental treatments under GA and oral health disparities in this pediatric population.

Sociodemographic, biological, and timing characteristics of dental caries and fluorosis using mixed-type cluster analysis on 12-year-olds in Ho Chi Minh city, 1989–2019

ObjectivesIn 1990, Ho Chi Minh City started Community water fluoridation (CWF) at 0.7 ppm F, and in 2000, it was adjusted to 0.5 ppm F. Here, we analyzed dental caries and fluorosis data in Ho Chi Minh City to explore commonalities associated with CWF among 12-year-old children. MethodsDental caries and fluorosis data were collected in 1989, 2003, 2012, and 2019 (N = 4773). Trained dentists scored dental caries using the WHO detection criteria and fluorosis using Dean's Fluorosis Index. We used these data and the k-prototypes method by the R package to identify clusters of participants with shared clinical and water fluoride levels. ResultsWe used datasets 1 (4773 participants) and 2 (4194 participants, missing fluorosis data in 1989). K-prototypes analysis identified three clusters in each dataset. Cluster 1, with 80 % of the sample at 0.5 ppm F area characterized by low caries and fluorosis scores. Cluster 2 with 60 % of the sample non-fluoridated area had high caries and low fluorosis scores. Cluster 3, with 75 % of the sample in 0.7 ppm area, had low caries but borderline high fluorosis scores. ConclusionIdentifying three clusters based on clinical and environmental scores supports the decision to fluoridate the water to prevent caries (0–0.7 ppm) and the shift from 0.7 to 0.5 ppm to keep the caries preventive effect while reducing the risk of fluorosis. Clinical significanceOur results support the effectiveness of CWF in preventing dental caries and the appropriateness of changing the F concentration to reduce the risk of fluorosis while maintaining its effectiveness.

Comments on recent community water fluoridation studies

Water fluoridation is a public health measure to reduce levels of dental caries in populations. A report of the recently completed CATFISH study has been published. This was the first UK evaluation of fluoridation introduction for many years; it was carefully designed and executed and is welcomed. The purpose of this article is to highlight the 180-page report of the study and comment on some aspects to aid interpretation of the findings. Significant features were that two cohorts, from birth and from five years, were followed for six years in a fluoridated and a non-fluoridated area, and clinical and cost analyses were reported. Areas of the report which deserve comment are: a) interruption of fluoridation for a year for half the children in the intervention area and its effect; b) clinical results were reported as absolute reduction in caries prevalence, with the preventive fraction for caries severity downplayed; c) the power of the study was diminished by an unexpected lower caries increment; and d) control for differences in diet was not possible. Nevertheless, this major UK study showed clinical and cost benefits of water fluoridation. The risk of cessation of water fluoridation is highlighted in examples of three recently published studies.

Impact of water fluoridation on dental caries decline across racial and income subgroups of Brazilian adolescents.

OBJECTIVESThe aim of this study was to assess the impact of community water fluoridation (CWF) on differences in dental caries decline across racial and socioeconomic subgroups of Brazilian adolescents.METHODSTwo nationwide Brazilian population-based oral health surveys were used (Brazilian Oral Health Survey 2003 and 2010). In total, 7,198 adolescents from 15 years to 19 years old living in 50 cities investigated in both surveys were included. The mean numbers of untreated decayed teeth (DT) according to racial (Whites vs. Browns/Blacks) and socioeconomic subgroups (at or above the minimum wage per capita vs. under) were analysed. Difference-in-differences negative binomial regressions were adjusted by schooling, age, and sex. Decayed, missing, and filled teeth and DT prevalence, calculated as a categorical variable, were used in sensitivity analyses.RESULTSThe adjusted difference of reduction in DT was similar across socioeconomic subgroups (β=-0.05; 95% confidence interval [CI], -0.45 to 0.35) and favoured, but not to a significant degree, Whites (β=-0.34; 95% CI, -0.74 to 0.04) compared to Brown/Blacks in fluoridated areas. In non-fluoridated areas, significant differences were observed in the mean number of DT, favouring the higher socioeconomic subgroup (β=-0.26; 95% CI, -0.53 to -0.01) and Whites (β=-0.40; 95% CI, -0.69 to -0.11) in relation to their counterparts. The sensitivity analyses confirmed the findings.CONCLUSIONSThe similar reduction in DT across income subgroups suggests that CWF has had a beneficial effect on tackling income inequalities in dental caries within a 7-year timeframe.

Effect of dentifrices with different pH and fluoride concentrations on fluoride levels in biofilm and nails: an RCT.

to evaluate the effect of dentifrice pH and fluoride concentration ([F]) on fluoride uptake on the biofilm and nails of children from a non-fluoridated area. two hundred and twenty-eight two- to four-year-old children were randomly allocated into 3 groups according to the type of dentifrice: G1: 1100 μg F/g, pH 4.5 (n = 76); G2: 750 μg F/g, pH 4.5 (n = 74); and G3: 1100 μg F/g, pH 7.0 (n = 78). Nails were collected at 4, 8, and 12 months after starting dentifrice use and biofilm was collected 5 and 60 minutes after toothbrushing. The concentrations of F in nails and biofilm were analyzed by HMDS facilitated diffusion. Data were analyzed by Kruskal-Wallis/Mann-Whitney's test and the comparison between biofilm collection times was done using Wilcoxon test (p £ 0.05). a significant reduction of [F] in biofilm was observed 60 minutes after toothbrushing, regardless of the dentifrice used. However, 5 minutes after toothbrushing, G1 had a significantly higher [F] compared to G2 and G3, and 60 minutes after toothbrushing, [F] was significantly higher for G1 and G2 compared to G3. G1 and G3 had significantly higher [F] in the nails compared to G2. a lower dentifrice concentration is a relevant factor for the reduction of excessive fluoride intake. The use of a low-F acidified dentifrice combines the reduction of fluoride uptake with caries prevention by leading to greater incorporation of F into the biofilm over time.

Estimation of fluoride uptake in soil and staple food crops produced in highly fluoridated and non-fluoridated regions of Raichur District, Karnataka.

A staple food crops have varied role in diet of people living in particular regions of world; hence, it is critical to recognize their productivity. Therefore, the purpose of this study was to estimate fluoride concentration in staple food crops grown in highly fluoridated and non-fluoridated regions and its correlation with soil. Total 36 samples were collected of which 18 samples consisting of each three samples of rice, redgram and jowar were selected. Likewise 18 corresponding soil samples from both areas were collected. All samples were ashed for 4-6 hours at 550°C in muffle furnace. The samples were allowed to cool, after which 10 ml distilled water was added to each sample and fluoride concentration was determined using ion selective electrode method, before each sample analysis the instrument was standardized using fluoride containing TISAB (III) buffer solution. The data was tabulated and subjected to cross-sectional observational statistical analysis using SPSS software applying unpaired t-test and Pearson's test. The mean fluoride concentration in crops and soils were rice (0.79 ppm), redgram (4.26 ppm), jowar (8.8 ppm) and in soil of rice (1.23 ppm), redgram (1.23 ppm) and jowar (1.21 ppm) respectively in fluoridated area. Where as in non-fluoridated area rice (0.07 ppm), redgram (0.81 ppm), jowar (0.81 ppm) and in soil of rice (0.61 ppm), redgram (0.07 ppm) and jowar (0.52 ppm) respectively. The resultant correlation between staple food crops with their corresponding soils were found highly significant in both regions with P value <0.005; hence, crops in fluoridated region exhibited increased fluoride retention, whereas crops in non-fluoridated region had optimal fluoride levels. Fluoride concentration in food crops has strong correlation with their respective soils and water irrigation properties.

Effectiveness of water fluoridation in an upper-middle-income country: A systematic review and meta-analysis.

To summarize the information on the effectiveness of community water fluoridation (CWF) on the reduction of dental caries in the context of the wide use of fluoridated toothpaste in Brazil. A systematic review was conducted regarding the effect of CWF based on studies with Brazilian population groups using the following electronic databases: MEDLINE/PubMed, LILACS, SciELO, and SCOPUS. The literature search was conducted up to August 2019. Studies that compared caries experience in at least two areas, one fluoridated and the other non-fluoridated, by mean dmft/DMFT (decayed, missing, and filled teeth) index or caries prevalence (caries vs. caries-free) were included. Considering the beginning of widespread use of fluoride dentifrice and the time for producing dental caries decline, studies published before 1995 were excluded. Descriptive analysis and meta-analyses were carried out. The effect size was measured by mean difference for dmft and DMFT±SD and odds ratios on a logarithmic scale for caries prevalence. Of the 574 studies retrieved, 16 and 10 were included in the qualitative and quantitative analysis, respectively. Fluoridated areas exhibited lower mean dmft/DMFT than non-fluoridated areas did. The mean difference in the dmft between non-fluoridated and fluoridated areas was -2.28 (95% CI -3.26; -1.30) for children aged 5-8years and -1.12 (95% CI -1.93; -0.32) for those aged 3-12years; the mean difference in the DMFT was -0.61 (95% CI -0.80; -0.42) for the children aged between 7 and 12years. The caries prevalence was 1.4 times and 57% lower, respectively, at primary and permanent dentition in fluoridated areas. Heterogeneity was observed in all age groups, ranging from 77.6% to 98.2%. Community water fluoridation remains effective in preventing dental caries in children younger than 13years, even with the widespread use of fluoridated toothpaste.

736Low Birth weight in new born, anaemia in pregnancy in Fluoride endemic areas of Rajasthan

Abstract Background Rajasthan has been documenting severe anaemia in pregnancy, resulting in low birth weight. Current study was planned to explore potential linkages between exposure to fluoride, anaemia in pregnancy and low birth weight in infant. Methods Antenatal mothers from one fluoride endemic district (FD) and one non-fluoride endemic district (NFD) of western Rajasthan were recruited and followed up till delivery. Data included socio-demographic, lifestyle, diet, medication history. Lab Investigations included Hb, Urinary Fluoride. Results Out of total 1401 women, mean age of women from FD were 23.87 (+ 3.8) yrs and from NFD were 25.53(+ 3.82) yrs. Mean fluoride values in the urine samples of pregnant females were found to be 2.06 (0.0 to 14.4 mg/L) in FD and 1.43 (0.00 to 12.7 mg/L) in NFD. Mean fluoride values in water samples were 0.72 (0.0 to 3.80 mg/L) in FD and 0.21 (0.0 to 2.69 mg/L) in NFD. Mean weight of newborn from FD were 2.92 (+ 0.47) yrs and from NFD were 2.94 (+ 0.56) kg. 22% Newborn in FD and 18% in NFD had low birth weight. Conclusions Infants born in Fluoride endemic area have lower birth weight as compared to non-Fluoride endemic area. Antenatal women in Fluoride endemic areas are more anaemic. Key messages Fluoride endemicity is an important factor to be considered while addressing Anaemia in pregnancy and Low Birth Weight Babies in Western Rajasthan, India.

Factors associated with dental fluorosis among Malaysian children exposed to different fluoride concentrations in the public water supply.

To determine the prevalence of dental fluorosis, and factors associated with its occurrence in two cohorts of children exposed to different fluoride concentrations in the Malaysian water supply. A cross-sectional study was conducted among lifelong residents (n=1,155) aged 9 and 12 years old living in fluoridated and nonfluoridated areas. Malaysian children aged 12 years were born when the level of fluoride in the public water supply was 0.7ppm while those aged 9 years were born after the level was reduced to 0.5ppm. Fluorosis was blind scored using standardized photographs of maxillary central incisors using Dean's criteria. Fluoride exposures and other factors were assessed by parental questionnaire. Data were analyzed using descriptive statistics, Chi-squared analyses, and logistic regression. Fluorosis prevalence was lower (31.9percent) among the younger children born after the reduction of fluoride concentration in the water, compared to a prevalence of 38.4percent in the older cohort. Early tooth brushing practices and fluoridated toothpaste were not statistically associated with fluorosis status. However, the prevalence of fluorosis was significantly associated with parents' education level, parents' income, fluoridated water, type of infant feeding method, age breast feeding ceased, use of formula milk, duration of formula milk intake, and type of water used to reconstitute formula milk via simple logistic regression. Fluoridated water remained a significant risk factor for fluorosis in multiple logistic regression. Fluorosis was lower among children born after the adjustment of fluoride concentration in the water. Fluoridated water remained as a strong risk factor for fluorosis after downward adjustment of its fluoride concentration.

Recruitment and Consent in an observational study.

The study sought to explore the consent rate and associated potential bias across a cohort in a large longitudinal population based study. Data were taken from a study designed to examine the effects of the reintroduction of community water fluoridation on children's oral health over a five-year period. Children were recruited from a fluoridated and non-fluoridated area in Cumbria, referred to as Group 1 and Group 2. Data were available for 3138 individuals. The consent rate was 12.91 percentage points lower in Group 2 than Group 1 (95% CI -16.27 to -9.56, p⟨0.001). The population in Group 2 was more deprived (higher Index of Multiple Deprivation (IMD)) than Group 1 before consent was taken. Consent was not associated with deprivation in either group. The cohort appeared to be unaffected by IMD-related non-consent. However there was a difference in consent rate between the two groups. With the population in Group 1 being more deprived than Group 2, it will be important to incorporate these differences into the analysis at the end of this longitudinal study.

What can we do to prevent small children from suffering from tooth decay?

Data sources Medline, Embase, CINAHL and PubMed.Study selection Studies published in peer-reviewed journals focusing on dental caries of primary teeth and risk and/or protective factors, in healthy children aged equal to or less than six years, including randomised controlled trials (RCTs) with an intervention period of at least one year for caries, other intervention studies, and observational studies (such as cohort, case-control, ecologic and cross-sectional studies); risk and/or protective factors included: breastfeeding beyond one year of age, breastfeeding beyond two years of age, consumption of liquids that contain free sugars from an infant feeding bottle, consumption of complementary drinks that contain free sugars, consumption of complementary foods that contain free sugars, oral hygiene provided by a parent/caregiver, oral health education for caregivers, water with an optimum concentration of fluoride, consumption of fluoridated milk and salt fluoridation.Data extraction and synthesis Five reviewers independently screened the title and abstract of the identified citations and 5% of them were screened by all reviewers. Data extraction was undertaken by two reviewers. The evidence was classified into 12 groups in accordance with the 12 review questions. Eligible studies were synthesised and meta-analysis performed where appropriate. Risk of bias was tested by the Cochrane 'risk of bias' tool for RCTs and the ROBINS-I for non-randomised trials. The quality of evidence related to each of the 12 review questions was assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).Results After initial search of 13,831 studies, 137 eligible studies were included in the systematic review and grouped into 10 out of 12 review questions (no eligible study was identified for two review questions). Among those ten review questions, only two review questions had RCTs to address the answers; others were answered by observational studies and/or quasi-experimental studies. A prospective cohort study displayed no significant difference was found in severity of caries among five-year-old children inbetween those breastfed for nearly 23 months and those breastfed up to one year. Observational studies showed increased risk of early childhood caries (ECC) was associated with consumption of sugar in both bottles and complementary foods. Results of meta-analysis of three RCTs stated that children of caregivers who received oral health education had lower chance of having ECC than those who had never received oral health education (OR 0.39, 95% CI 0.19 to 0.79, P = 0.009). Another result from meta-analysis demonstrated that lower pooled mean dmft was found in children living in areas with fluoridated water than those who lived in non-fluoridated areas (-1.25, 95% CI -2.14 to -0.36, P = 0.016). Children who consumed fluoridated milk and fluoridated salt reduced the risk of ECC compared to those who did not. No publication bias was observed in the meta-analysis.Conclusions Evidence with moderate quality demonstrated that children with access to fluoridated water and fluoridated supplements could lower their risk of ECC; children with caregivers who had received oral health education had lower levels of ECC. Evidence with low quality suggested that breastfeeding up to two years old did not increase the risk of ECC; consumed sugars in bottles and complementary foods increased the risk of ECC.

Cost-effectiveness of adding fluoride varnish to a preventive protocol for early childhood caries in rural children with no access to fluoridated drinking water

ObjectivesEvidence of the cost-effectiveness of fluoride varnish in the prevention of caries is not yet fully conclusive. The aim of this study was to assess the incremental cost-effectiveness ratio (ICER) of the community-wide application of fluoride varnish in the prevention of early childhood caries (ECC) in non-fluoridated areas. Materials and methodsA cost-effectiveness analysis was carried out based on a clinical decision tree from the payer’s perspective. The effectiveness and cost of the varnish were determined from a two-year follow-up triple-blind randomized control trial in 275 two- to three-year-old children. Costs and benefits were discounted at 3% per year. Only direct costs were evaluated, expressed in Chilean pesos (CLP) valued in July, 2019 (exchange rate USD = CLP686.06). A univariate deterministic sensitivity analysis was carried out. ResultsIncidence of ECC was 45 % for the varnish group and 55.6 % for the placebo group with a two-year follow-up. The weighted cost to intervene and treat the consequences of ECC was CLP 67,757 (USD98.76) for the fluoride varnish and CLP 67,739 (USD98.74) for the control group. The ICER was CLP 173 (USD0.25) for each extra healthy child in favor of fluoride varnish. The sensitivity analysis showed that the increase in caries was the variable which most influenced the ICER. ConclusionsThe protocol that included fluoride varnish is more effective and less costly in the prevention of ECC in non-fluoridated areas, compared with a placebo. Clinical significanceFindings support the application of fluoride varnish as a cost-effective community strategy to prevent ECC in non-fluoridated areas.

Prevalence and genetic correlation evaluation of dental fluorosis in rural population of Nagpur, India

Dental fluorosis (DF) is a tooth malformation related to ingestion of high amount of fluoride (F) during tooth development. According to various surveys (1994 , 2000 & 2002), it is clearly established that DF has increased incidences rates in the areas with fluoridated water ranging from 7.7% upto 80.9% and only 2.9% to 42% in areas without fluoridated water. It was being observed that 10-20% of the rural population reported to department with dental fluorosis belonged to non-fluoridated areas. Several studies suggested that there was a weak corelationship between drinking water & DF severity. Aim: The present study was undertaken to investigate prevalence of dental fluorosis and hereditary patterns of dental fluorosis in identified individuals among rural population in vicinity of Nagpur district. Materials and Methods: A case control study was conducted at six rural places around Nagpur. The fluoride content was estimated from sample of drinking water from well and tap.384 individuals were selected using systematic random sampling method. A detailed case history was taken followed by reporting of DMFT and DMFS indices. The collected data was analyzed statistically using students’t test. Results: All the water samples tested reported F concentration varying with 0.267 to 1.081mg/ml. Prevalence of DF for individuals consuming well water(62.1%) was found to be significantly higher(p Conclusion: There was no correlation with DF and F concentration in drinking water, however its strong correlation exists with genetic component. Keywords: Dental fluorosis (DF)

Surprisingly high fluorine content in some exotic superfoods

Recent years have seen soaring interest in exotic superfoods, which are believed to have extraordinary health benefits. The purpose of the study was to broaden the current knowledge on exotic superfoods and to analyse them for fluorine (F)11In this paper, “fluorine” is used to denote the element in any of its forms and “fluoride” is used to denote the inorganic compound and the fluoride ion F−. since excessive intake during prolonged periods of time can cause adverse effects. The F content was determined in 18 plant-based exotic superfoods available on Slovenian market by fluoride ion selective electrode after prior total decomposition by alkaline carbonate fusion. In 8 of the analysed samples, the F content was surprisingly high in comparison to F content in commonly consumed foods (<3 μg/g). The highest F content was found in matcha (373 μg/g), followed by gotu kola (111 μg/g) and gingko biloba (91.0 μg/g). The F content in tulsi, neem, brahmi, gynostemma and moringa was lower and ranged between 16.4–68.8 μg/g. Despite high F content, these superfoods do not pose a risk to human health in non-fluoridated water areas, because they are usually consumed in low quantities. However, in fluoridated water areas (e.g. some parts of Ireland, United Kingdom, United States, Canada) or in areas with high natural fluoride concentration in drinking water, superfoods should be consumed with caution, since the intake of F can with simultaneous consumption of superfoods and tea on a normal diet easily exceed the adequate intake or even reach the upper limit of fluorine. The F content in these 8 superfoods was also surprisingly high in comparison to the usual F content in most plant species (<10 μg/g). The high F content in matcha is understandable since it is made of Camellia sinensis L. leaves, but the high F content in other superfoods is worrisome because the reason for such high F content is unknown and it is possible that these superfoods are contaminated with fluoride due to industrial or agricultural activities.

The prevalence of enamel and dentine caries lesions and their determinant factors among children living in fluoridated and non-fluoridated areas.

To determine the prevalence and severity of dental caries (at dentine and enamel levels of diagnosis) amongst Malaysian children and to investigate determinant factors associated with caries detection at these different thresholds. This study involved life-long residents aged 12 years-old in fluoridated and non-fluoridated areas in Malaysia (n=595). The survey was carried out in 16 public schools by a calibrated examiner, using ICDAS-II criteria. A questionnaire on socio-demographic and oral hygiene practices was self-administered by parents/guardians. Data were analysed using Mann-Whitney U tests and logistic regression. The overall response rate was 74.4%. Caries prevalence at the dentine level or at the dentine and enamel level was significantly (p⟨0.001) higher among children in the non-fluoridated area (D₁₋₆MFT⟩0 = 82.4%, D₄₋₆MFT⟩0 = 53.5%) than in the fluoridated area (D₁₋₆MFT⟩0 = 68.7%, D₄₋₆MFT⟩0 = 25.5%). Considering only the decayed component of the index, no significant differences were observed between the two areas when the detection threshold was set at enamel caries (D₁₋₃) (p=0.506). However, when the detection criteria were elevated to the level of caries into dentine (D₄₋₆) there were clear differences between the fluoridated and non-fluoridated areas (p=0.006). Exposure to fluoridated water proved a significant predictor for lower caries prevalence in the statistical model. Children whose father and mother had a low monthly income had a significantly higher dentine caries prevalence. Results confirmed existing evidence of the benefit of water fluoridation in caries prevention. Detection criteria set at caries into dentine shows clear differences between fluoridated and non-fluoridated areas. Exposure to fluoridated water and socio-economic status were associated with caries prevalence.

Fluoride retention in infants living in fluoridated and non-fluoridated areas: effects of weaning.

Limited knowledge is available on total fluoride exposure, excretion and retention in infants, despite the first year of human life being the critical period for dental development and risk of dental fluorosis. This study investigated total daily fluoride intake (TDFI), excretion (TDFE) and retention (TDFR) in infants living in fluoridated and non-fluoridated water areas at pre- and post-weaning stages of development. Healthy infants, aged 0-12 months, were recruited and their TDFI (mg/kg body weight (BW) per d), from diet and toothpaste ingestion, was assessed over a 3-d period using a dietary diary and tooth-brushing questionnaire. TDFE (mg/kg BW per d) was estimated by collecting 48-h urine and faeces. TDFR (mg/kg BW per d) was estimated by subtracting TDFE from TDFI. A total of forty-seven infants completed the study: sixteen at pre-weaning and thirty-one at post-weaning stages, with a mean age of 3·4 and 10·0 months, respectively. TDFI was lower in the non-fluoridated area (P&lt;0·001) and at the pre-weaning stage (P=0·002) but higher in formula-fed infants (P&lt;0·001). TDFE was mainly affected by type of feeding, with higher excretion in formula-fed infants (P&lt;0·001). TDFR was lower in the non-fluoridated area (P&lt;0·001) and at the pre-weaning stage (P&lt;0·001) but higher in formula-fed infants (P=0·001). In conclusion, a relatively large proportion of fluoride intake is retained in the body in weaned infants. This is an important consideration in fluoride-based prevention programmes, with goals to maximise caries prevention while minimising the risk of dental fluorosis.

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

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. A cross-sectional study recruited a sample with lifetime exposure to water fluoridation and a matched, nonexposed group. 580 participants, aged 18-52years (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. 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. 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.

Influence of Fluoridated Groundwater and 1,100 Ppm Fluoride Dentifrice on Biomarkers of Exposure to Fluoride.

This research aimed to determine the influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride in preschoolers. A cross-sectional study was performed on thirty preschoolers recruited from naturally fluoridated and non-fluoridated areas (n=15). Total Daily Fluoride Intake (TDFI) from diet and dentifrice, and Daily Urinary Fluoride Excretion (DUFE) was measured over 24 h. Nails samples were collected twice during 30 days. Fluoride analyses were performed using a fluoride-ion-specific electrode. Data were evaluated using the Student and paired t-test, Pearson correlation analysis, multiple linear regression analysis (α≤0.05). Fluoridated groundwater and dentifrice were the dominant sources (r2 > 0.83) of TDFI in children from a naturally fluoridated and a non-fluoridated area, respectively. A positive correlation between TDFI and DUFE (r=0.50), and between [F] in fingernails and toenails (r=0.60) were found in children from a naturally fluoridated area. The [F] in nails of finger and toe were not correlated to TDFI. The consumption of fluoridated groundwater influenced the fluoride concentration in urine. In addition, the use of 1,100 ppm fluoride dentifrice did not influence the fluoride concentration in urine and fingernails.

The impact of a reduction in fluoride concentration in the Malaysian water supply on the prevalence of fluorosis and dental caries

To assess the prevalence and severity of dental fluorosis and caries among Malaysian children following the reduction in fluoride concentration from 0.7 to 0.5 parts per million (ppm) in the public water supply. This study involved lifelong residents aged 9- and 12-year-olds in fluoridated and nonfluoridated areas in Malaysia (n=1155). In the fluoridated area, children aged 12years and 9years were exposed to 0.7 and 0.5ppm, respectively, at the times when maxillary central incisors developed. Standardized photographs of maxillary central incisors were blind scored for fluorosis using Dean's criteria. Dental caries was examined using ICDAS-II criteria. The prevalence of fluorosis (Dean's score≥2) among children in the fluoridated area (35.7%, 95% CI: 31.9%-39.6%) was significantly higher (P<0.001) than children in the nonfluoridated area (5.5%, 95% CI: 3.6%-7.4%). Of those in the fluoridated area, the prevalence of fluorosis decreased from 38.4% (95% CI: 33.1%-44.3%) for 12-year-olds to 31.9% (95% CI: 27.6%-38.2%) for 9-year-olds, although this difference was not statistically significant (P=0.139). The mean caries experience in the permanent dentition was significantly lower in the fluoridated area than in the nonfluoridated area for both age groups (P<0.05). In the multivariate models, the difference in the differences of caries experience between fluoridated and nonfluoridated areas remained statistically significant. This suggests that caries-preventive effect is still maintained at 0.5ppm. Findings indicate that the change in fluoride level from 0.7 to 0.5ppm has reduced fluorosis and maintains a caries-preventive effect. Although there is a reduction in fluorosis prevalence, the difference was not statistically significant.

Automatic detection and classification of dental fluorosis in vivo using white light and fluorescence imaging

ObjectivesTo assess a novel method of automatic fluorosis detection and classification from white light and fluorescent images. MethodsDental images from 1,729 children living in two fluoridated and two non-fluoridated UK cities were utilised. A novel detection and classification algorithm was applied to each image and TF scores were obtained using thresholding criteria. These were compared to clinical reference standard images. Comparisons between reference and automated assessments were undertaken to record correct and incorrect classifications and the ability of the system to separate the fluoridated and non-fluoridated populations. ResultsThe automated system performed well and was able to differentiate the two populations (P < 0.0001) to the same degree as the reference standard. When using the highest score from the clinical assessment the agreement between automated and clinical assessments was 0.56 (Kappa SE = 0.0160, p < 0.0001). ConclusionsAssessment of dental fluorosis is typically undertaken by clinical examiners in epidemiological studies. The training and calibration of such examiners is complex and time consuming and the assessments are subject to bias – frequently because of the examiner’s awareness of the water fluoridation status of subjects. The use of remote scoring using photographs has been advocated but still requires trained examiners. This study has shown that image-processing methodologies applied to white light and fluorescent images could automatically score fluorosis and statistically separate fluoridated and non-fluoridated areas. The system requires further refinement to manage confounding factors such as the presence of non-fluoride opacities and tooth stain.