Prevalence of dental fluorosis in rural areas of Davangere, India

OBJECTIVES: To assess the prevalence and severity of dental fluorosis and its relationship with fluoride levels in drinking water. DESIGN: Twelve villages with similar climate, diet, socioeconomic conditions and altitudes were selected from rural areas of Davangere district, Karnataka, India. The fluoride concentration in drinking water was estimated by the Ion Selective Electrode Method. Dean's Index was used to assess the dental fluorosis. Karl-Pearson coefficient for correlation and simple regression analysis were used to evaluate the association between the water fluoride levels and the community fluorosis index (CFI). RESULTS: The study group consisted of 1,131, 12-15-year-old school children. The fluoride levels in drinking water of selected villages were in the range of 0.22-3.41ppm. A stepwise increase in the prevalence of dental fluorosis with corresponding increase in water fluoride content, 13.2% at 0.22ppm F to 100% at 3.41 ppm F, was found. There was a significant positive linear correlation (r=0.99) between CFI and water fluoride level. CONCLUSION: Dental fluorosis is a major dental public health problem among children in Davangere district and is related to drinking water with 0.74ppm fluoride or above.     

Dental Fluorosis Following Downward Adjustment of Fluoride in Drinking Water

The drinking water fluoride concentration in Hong Kong was reduced by about 0.2 ppm in June 1978. This study was undertaken to determine whether the prevailing level of dental fluorosis was affected by such a minor change. Cohorts of children (N = 1,062) aged seven to 12 years, who were born both before and after the fluoride reduction, were examined clinically using Dean's fluorosis index. Based on upper right central incisors, dental fluorosis prevalence decreased from 64 to 47 percent and the community fluorosis index decreased from 1.01 to 0.75 (P less than .01). Thus, dental fluorosis was reduced, although the reduction in water fluoride concentration was not sufficient to achieve the minimal fluorosis level that Dean associated with a fluoride concentration optimal for caries prevention. Variation in dental fluorosis has been reported previously to result from marked sudden changes, during tooth formative years, to drinking water fluoride concentration. This study confirms preliminary findings that variation in dental fluorosis arising from minor changes to the fluoride level in drinking water is also measurable.     

广东东部饮水氟适宜浓度的探讨广东东部饮水氟适宜浓度的探讨

目的：探索广东东部饮水氟适宜浓度。方法：在广东东部,对饮用0.1-2.5mg/L不同水氟浓度水的1237名9-17岁、35-44岁居民,进行龋病和氟牙症检查;并通过问卷调查,对可能接触氟的生活习惯进行研究;让受检者对氟牙症牙色进行自我评价。结果：水氟浓度是影响氟牙症发生的最主要因素,氟牙症随水氟浓度升高加重,而随水氟浓度升高,龋均则下降,当水氟浓度为0.57mg/L时,氟牙症指数为0.4,水氟浓度为0.7mg/L时,氟牙症指数为0.6。当地居民对氟牙症流行可接受程度与Dean所订标准相符。结论：广东东部饮水氟适宜浓度建议为0.57mg/L,最高允许浓度为0.7mg/L。     

Estimation of optimal concentration of fluoride in drinking water under conditions prevailing in Chile

Abstract– The purpose of this comparative study of caries and dental fluorosis experience in Chilean children was to estimate the optimal range of fluoride concentration in tap water under conditions currently prevailing in Chile. The sample included 2431 schoolchildren 7, 12 and 15 years old, life-long residents of five communities with fluoride concentrations in their tap water in the range 0.07–1.1 mg/L. The study population received an oral clinical examination including caries experience and an enamel fluorosis evaluation of the permanent dentition (Dean's scoring system). For 15-year-old children, the DMFT index changed from 5.06 to 2.60, and for 12-year-olds it changed from 3.10 to 1.36 when fluoride water concentration changed from 0.07 to 1.10 mg/L. For 7-year-old children the dmft index correspondingly changed from 3.67 to 1.59. The relationship between DMFT for 12-year-olds and water fluoride concentration was best fitted by a logarithmic function ( r ²=0.98). The Community Fluorosis Index (CFI) was used to assess enamel fluorosis in the study population, and it showed a linear relationship ( r ²=0.983) with increasing fluoride concentration of water for the 12-year-old group. Results obtained suggest that under current Chilean conditions, the optimal range of fluoride concentration in potable water should lie in the 0.5–0.6 mg/L range.     

The appearance of tooth enamel in children ingesting water with a high fluoride content for a limited period during early tooth development

Sixteen Japanese children, inadvertently exposed to drinking water containing 7.8 ppm fluoride (F) from birth, were aged 11 to 42 months when a low-F water supply was substituted. The appearance of the enamel of their permanent teeth was assessed 11 years later (children aged 12-15 years) and recorded using Dean's and the FDI indices. All grades of Dean's classification were seen. The enamel lesions were more severe in the older than in the younger children, in the incisal compared with the gingival halves of the teeth, and in the early- compared with the late-forming teeth. Small, localized, chalky-white areas of enamel were found at or close to the incisal margins of the anterior teeth of six children. The characteristics and the distribution of the lesions in this study add to our knowledge of the mechanism by which fluoride produces dental fluorosis.     

The prevalence and severity of enamel fluorosis in North American children

The question considered in this review is the extent to which changes in the prevalence or severity of enamel fluorosis have occurred over the last half-century. Emphasis is given to a review of those studies in which subjects are drinking water that is fluoride deficient and those in which subjects are drinking optimally fluoridated water, either adjusted or natural. Trends in fluorosis were examined using two definitions of fluorosis (definite and any signs) and three types of comparisons--comparisons of pooled estimates from all available studies that include data from different communities and time periods, comparisons of estimates from the same communities at different times, and comparisons of estimates from selected studies in the early years of fluorosis research with results of the US National Fluorosis Survey done by the National Institute of Dental Research. A clear increase in fluorosis among populations drinking community water that contains less than 0.3 ppm fluoride was found. Results of the comparisons using studies with Dean's Index pooled at different time points, comparisons in the same communities over time, and comparisons of prevalence found in selected communities before fluoride was widely available with the National Fluorosis Survey all support this conclusion. An increase in the prevalence of fluorosis in those drinking optimally fluoridated water likely has occurred as well; however, evidence for such a trend is not as clear as for fluoride deficient communities because of mixed results depending on the type of comparison. The majority of fluorosis cases continue to be mild and seem of little esthetic consequence for most of the public or dental profession. But a few cases of more severe fluorosis can be found now in some communities. Because the prevalence of fluorosis is now higher than 50 years ago, we can conclude that fluoride availability to the developing enamel during critical periods when enamel is at risk of fluorosis has increased in North American children.     

Distribution of dental fluorosis in the primary dentition

By the use of a new classification system of dental fluorosis, primary and permanent teeth were examined in samples of children born in areas with 3.5, 6.0 and 21.0 parts/10(6) F- in the water supplies. The severity of dental fluorosis was lower than in the corresponding permanent teeth, but a significant increase in severity was noted with increasing concentration of fluoride in the drinking water. The distribution of dental fluorosis within the dentition followed the same pattern irrespective of fluoride content of the water. Thus, a progressive increase in severity was noted from the anterior to the posterior teeth. This pattern is presumably determined by variations in enamel thickness. The much thinner enamel layer of primary teeth may also explain the lower degree of dental fluorosis in these teeth rather than a maternal barrier to fluoride. The degree of dental fluorosis observed in medium and high fluoride areas did not support the hypothesis that the rapidly growing skeleton of infants prevents fluoride-derived enamel changes.     

黑龙江省12岁儿童患龋状况与饮水氟浓度关系的抽样调查

目的:研究黑龙江省不同地区12岁儿童龋齿和氟斑牙的发病情况与当地饮水氟浓度的关系。方法:按照WHO《口腔健康调查基本方法》的要求,采用多阶段分层等容量随机抽样方法,抽取全省城乡6个地区的12岁年龄组792例儿童进行龋齿和氟牙症调查。采用SPSS12.0软件包进行统计学分析。结果:6个地区饮水氟浓度分别为0.29、0.40、0.68、0.77、0.80和1.14mg/L;相应的患龋率为44.7%、43.2%、41.7%、37.1%、28.0%和40.5%。除饮水氟浓度1.14mg/L组外,随着饮水氟浓度的增高,患龋率有下降趋势,两者呈负相关关系(r=-0.81)。社区氟牙症指数(CFI)与饮水氟浓度呈正相关关系(r=0.78)。结论:适当的饮水氟浓度可有效降低龋齿的发病率,在水氟过高的情况下,可能会引起龋病和氟牙症的高发。     

Perceptions of fluorosis in northern Cape communities.

The objective of the study was to determine the perception of fluorosis in communities living in the Northern Cape Province of South Africa where there is a considerable range in fluoride levels of drinking water. The fluoride levels of the drinking water were categorised as suboptimal (0.40-0.60 ppmF), optimal (0.99-1.10 ppmF) or supra-optimal (1.70-2.70 ppmF). The teeth of 694 children aged 6, 12 and 15 years were examined. Dental fluorosis occurred among children of all ages in all areas studied. As anticipated there appears to be a direct relationship between fluoride levels in the drinking water and levels of dental fluorosis, and the severity of the condition increased with an increase in levels of fluoride in the water supplies. Children in low fluoride areas showed some form of mild fluorosis (37% very mild and 17% mild). However, 19% of this group experienced moderate or severe forms of fluorosis. In areas with optimal levels of fluoride 30% of children showed a questionable form of fluorosis and 21% mild fluorosis. Moderate or severe forms of fluorosis were recorded in 31% of children in the optimal fluoride area. The Community Fluorosis Index (CFI) scores for the sub-optimal and optimal areas were of medium public health significance and for the supra-optimal area of very high public health significance. Of concern is the high percentage of children (45%) in the supra-optimal area with severe forms of fluorosis. The awareness and concern for stains on teeth were mostly expressed by children with moderate or severe fluorosis. This study suggests that the proposed fluoride concentration (not more than 0.7 ppmF) prescribed in the Regulations on Fluoridating the Water Supplies for South Africa would minimise the risk of dental fluorosis.     

Fluoride and enamel defects

The concentration of fluoride in drinking water is the major determinant of the prevalence and severity of dental fluorosis in a community. Fluorosis is more prevalent and discernible in permanent teeth than in primary teeth; the intensity can range from barely perceptible, whitish striations in enamel to confluent pitting and dark staining. The traditional belief is that fluorosis is produced only during the secretory stages of ameloblastic activity. Some recent reports suggest that the maturation stages of enamel development are as important as or even more important than the secretory stages as the time when fluorosis can be produced. The question of timing remains unresolved. Many questions also remain about general and individual physiologic variations in relation to susceptibility to dental fluorosis. Good criteria for differential diagnosis exist to distinguish dental fluorosis from non-fluoride enamel opacities. An increasing number of reports indicates that the prevalence of fluorosis may be increasing among children in fluoridated and non-fluoridated communities. Reasons for the increases may relate to misuse of dietary fluoride supplements, ingestion of fluoride toothpastes, or increasing amounts of fluoride in foods or the atmosphere. The intensity of the increased fluorosis is in the milder categories and is not generally unsightly. It should be recognized that a small amount of fluorosis may be an alternative to a greater prevalence of dental caries, a disease that may produce cosmetic problems and sequelae worse than those produced by fluorosis.     

Indexes for Measuring Dental Fluorosis

Dental fluorosis, a hypoplasia or hypomineralization of tooth enamel or dentin, ranges in intensity from barely noticeable whitish striations to confluent pitting and staining. Various indexes or classification systems have been used in surveys to measure the presence and severity of enamel fluorosis. Other systems and indexes record all defects in enamel, based on a premise that an etiology for the condition should not be presumed. If all defects are recorded, a retrospective attempt to reconstruct which of them are fluorosis is inappropriate. Dean's classification system has been used most frequently over the years for assessing fluorosis. Therefore, its continued use is sometimes important for historical comparisons. Dean's system, however, has several shortcomings, principally its inability to measure fluorosis in different tooth surfaces. As it has been traditionally used, it also does not permit specifying the cosmetic importance of the most severe fluorosis detected in a dentition. The Tooth Surface Index of Fluorosis (TSIF) eliminates or reduces some of the shortcomings of Dean's method. Use of the TSIF in a survey in Illinois was able to discriminate between the prevalence and severity of fluorosis in four groups of communities with different concentrations of fluoride in their drinking water.     

陕西大荔县改水对氟牙症患病情况的影响

目的　观察陕西省大荔县龙门和皇都两村改水前后氟牙症的发病及流行情况 ,探讨改水对氟牙症发生的影响。方法　将 2 91名中小学生分为 2个组 ,①改水后组 :年龄 10～ 11岁 ,在改水1～ 2年以后出生 ,一直饮用含氟量为 1 2mg/L的新水源。②改水前组 ,年龄 15～ 16岁 ,在改水前4～ 5年出生 ,即在牙冠的形成发育期饮用 2 0～ 10 0mg/L的高氟水。根据Dean′s分类法记录受检者的牙齿情况。用t检验和 χ2 检验进行统计学分析。结果　①改水前后两组的患病率分别为87 2 %和 4 8 8% ,改用新水源后 ,氟牙症的患病率下降了 38 4 % ,其中改水前组中到重度氟牙症患病率分别为 32 0 %和 8 8% ;改水后组为 13 9%和 0。流行指数由 2 11降为 1 0 1,差异有高度显著性(P =0 0 0 )。②改水前两村间的患病率分别为 90 7%和 82 0 % ,差异无显著性 ;改水后的患病率分别为 5 7 1%和 38 7%。龙门村高于皇都村 ,差异有显著性 (P =0 0 18)。③在各组之间 ,女性的患病率均高于男性 ,但差异无统计学意义。结论　①改用含氟量为 1 2mg/L的水源后 ,明显降低了氟牙症的发生 ;② 1 2mg/L的水氟含量对大荔县人群来说仍然偏高 ,需要进一步采取措施 ,降低该地区饮水中氟的含量。     

Dental caries, its surface susceptibility and dental fluorosis in South India

OBJECTIVES: To correlate water fluoride levels with dental caries and dental fluorosis in areas with different levels of fluoride in the drinking water and to establish the surface susceptibility of dental caries in an endemic fluoride area. METHODS: 544 schoolchildren 12 to 15 years of age from the Davangere region of India were examined. The DMFS index was used to measure dental caries, which was further differentiated into smooth surface and pit and fissure lesions. Dean's index was used to diagnose dental fluorosis. Five villages with fluoride levels ranging from 0.43 ppm to 3.41 ppm were studied. RESULTS: There was a highly significant negative correlation (r = -0.16) between water fluoride levels and dental caries. Dental fluorosis increased from 16% at 0.43 ppm to 100% at 3.41 ppm. Pit and fissure lesions made up the vast majority of the lesions in all the villages and showed a decreasing trend with increasing fluoride levels, however no such trend was seen for smooth surface lesions. CONCLUSIONS: Water fluoride was an important factor responsible for the low caries prevalence. The prevalence of fluorosis and low caries even in low fluoride areas may point to a halo effect.     

Fluoride intake from food and liquid in Japanese children living in two areas with different fluoride concentrations in the water supply

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

Associations among dental caries experience,fluorosis, and fluoride exposure from drinking water sources in Saudi Arabia

Objectives: a) To correlate fluoride levels in drinking water sources with caries experience and dental fluorosis in Saudi Arabia, and suggest appropriate fluoride concentration for drinking water in the country. Methods: Fluoride levels were determined from 3,629 samples obtained from drinking water sources in 11 regions of Saudi Arabia. Based on the fluoride concentrations, a stratified sample of subjects aged 6‐7, 12‐13, and 15‐18 years was obtained from the regions. A total of 12,200 selected subjects were examined for dental caries according to the World Health Organization criteria, and dental fluorosis, using Thylstrup and Fejerskov classification. Results: There was an inverse relationship between fluoride exposure and caries experience, but the prevalence of dental fluorosis increased with increase in fluoride concentration. There was no significant difference in caries experience or in the prevalence of dental fluorosis when fluoride levels increased from 0.3 ppm to 0.6 ppm. In contrast, caries experience was lower, while severity of fluorosis was significantly higher at fluoride levels above 0.6 ppm. Conclusions: a) Fluoride levels in drinking water sources in Saudi Arabia correlate significantly with caries experience and prevalence of dental fluorosis. b) Appropriate fluoride concentration for drinking water in Saudi Arabia may be about 0.6 ppm.     

Urinary fluoride levels and prevalence of dental fluorosis in three Brazilian cities with different fluoride concentrations in the drinking water

Urine samples from three daytime periods were collected from 545 5–50-year-old residents of three different Brazilian cities: Garça had fluoridated drinking water since 1973, Bauru since 1975 and Itápolis was not fluoridated. Dental fluorosis was examined in 985 5–24-year-olds using the Thylstrup-Fejerskov index (TF). The subjects were asked to estimate their daily intake of liquids and frequency of beverage consumption. The analysis of 94 water samples showed high variations in the fluoride content of the drinking water. The mean fluoride concentration of the water samples in Garça was 0.9 mg/L (range 0.75–1.2), in Bauru 0.64 mg/L (range 0.01–1.3), and in Itápolis 0.02 mg/L. Mean urinary fluoride concentration was 1.31 mg/L ( s 0.61) in Garça, 0.88 mg/L ( s 0.49) in Bauru, and 0.39 mg/L ( s 0.21) in Itápolis. Self-reported daily liquid intake was not related to urinary fluoride concentration. The mean prevalence of fluorosis was 13.3% in Garça, 6.8% in Bauru, and 1.7% in Itápolis, with mainly categories TF 1 and TF 2 being recorded. Subjects with dental fluorosis tended to show a higher mean urinary fluoride concentration but the difference was not statistically significant. The study showed that fluoride exposure measured by urinary fluoride excretion was within the range expected for the level of fluoride concentration in the drinking water. However, enamel fluorosis tended to be markedly lower than expected. This study revealed that fluoride levels in the two cities with fluoridated drinking water were variable. To optimise anticaries benefits and minimise the risk of fluorosis greater control of the fluoride dosing of the drinking water is required.     

Determining optimal levels of fluoride in drinking water for hot, dry climates -a case study in Sri Lanka

The prevalence of dental caries and dental fluorosis was examined in 380 14-yr-old children living in four geographic areas of Sri Lanka with water F-levels of 0.09-8.0 ppm. A reduction in caries prevalence by 43% was recorded in children consuming 0.6-0.79 ppm F- compared to those in low fluoride areas (< 0.4 ppm). Among those consuming drinking water containing < 1.0 ppm F-, however, 32% of the children had mild forms and 9% severe forms of dental fluorosis (Dean's index). Although other sources of F- may contribute to this effect, the prevalence and severity of dental fluorosis seen in low fluoride areas was confirmed to be high in rural Sri Lanka. Our data are comparable with recent findings from other tropical countries, e.g. Kenya and Senegal, and reaffirm that WHO guidelines for the upper limit of F- in drinking water may be unsuitable for developing countries with a hot, dry climate. Current knowledge now enables us to recommend 0.8 ppm as an appropriate upper limit for F- in drinking water supplies for these populations.     

Fluoride exposure and dental fluorosis in Newburgh and Kingston, New York: policy implications

OBJECTIVES: This analysis was conducted to determine the changes in the effect of exposure to fluoridation and other sources of fluoride on dental fluorosis in children attending Newburgh and Kingston school districts in New York State. METHODS: Data for this analysis were obtained from two surveys conducted in the 1986 and 1995 school years. Analyses were limited to 3500, 7-14-year-old lifelong residents of a fluoridated or a nonfluoridated community. Dean's classification and DMFS index were used for recording dental fluorosis and caries, respectively. A questionnaire was used to collect fluoride exposure data. Regression procedures were used to estimate the effect of fluoridation, fluoride supplements, and brushing before the age of 2 years on dental fluorosis. RESULTS: Children examined in 1996 were at higher risk for both questionable and very mild to severe dental fluorosis if they received fluoride from water or daily tablet use, or started brushing before the age of 2 years. The increase in risk from 1986 to 1995 was greater for African-American children. CONCLUSION: This analysis showed that the risk of developing dental fluorosis did not decline over time in these communities. Continuous exposure to water fluoridation had an observable effect on dental fluorosis. However, implementation of fluoridation in Newburgh Town did not result in an increase in dental fluorosis prevalence.     

Determining the optimal concentration of fluoride in drinking water in Pakistan

OBJECTIVES: This study was designed to determine the optimal concentrations of fluoride for drinking water in Pakistan. Clinical dental examination of 1020 school children aged 12 years was carried out in 19 cities of Pakistan. Correlation between concentrations of water fluoride, caries and fluorosis was investigated by analyzing the data on fluoride concentrations in drinking water in the sampled population for which the caries and the fluorosis levels were also measured. METHODS: The optimal level of fluoride in drinking water is universally calculated by applying the equation of Galagan and Vermillion, which permits the calculation of water intake as a function of temperature. The annual mean maximum temperatures (AMMT) recorded during the last 5 years were collected from the meteorological centres of the 28 divisional headquarter stations. The average AMMT of Pakistan is 29 degrees C at which the optimal fluoride in drinking water of Pakistan was calculated to be 0.7 ppm. As drinking habits differ in various parts of the world, determination of optimal concentration of fluoride for drinking water in Pakistan was performed using a modified Galagan and Vermillion equation, which applies a correction factor of 0.56 to the equation. The optimal fluoride in drinking water in Pakistan using this modified equation was determined to be 0.39 ppm. RESULTS: Observation of the correlation showed that a fluoride concentration of 0.35 ppm in drinking water was associated with maximum reduction in dental caries and a 10% prevalence of fluorosis. CONCLUSIONS: Determining the most appropriate concentrations of fluoride in drinking water is crucial for communities. It is imperative that each country calculates its own optimal level of fluoride in drinking water based on the dose-response relationship of fluoride in drinking water with the levels of caries and fluorosis. Climatic conditions, dietary habits of the population and other possible fluoride exposures need to be considered in formulating these recommendations.     

Dental Fluorosis and Caries Prevalence in Children Residing in Communities with Different Levels of Fluoride in the Water

Objectives: This study investigated the prevalence of dental fluorosis and caries in 7–14-year-old children residing in communities with negligible (NF: 0.2 ppm), optimal (OPF: 1.0 ppm), and four-times optimal (4X OPF: 4.0 ppm) naturally occurring fluoride in their water systems. Methods : Examinations were performed on 344 children who were lifetime residents of their communities. Results : Whether using the tooth surface index of fluorosis or Dean's index, children examined in the 4X OPF community had the highest prevalence of dental fluorosis. While the severity of fluorosis seen in the OPF and NF communities was mild in appearance, the results indicate that fluorosis does occur in optimally and negligibly fluoridated communities. Compared to the NF community, DMFT and DMFS scores in the OPF community were 9.2 percent and 21.2 percent lower, respectively. Conclusions : The ingestion of water containing 1 ppm or less fluoride during the time of tooth development may result in dental fluorosis, albeit in its milder forms. However, in these times of numerous products containing fluoride being available, children ingesting water containing 1 ppm fluoride continue to derive caries protection compared to children ingesting water with negligible amounts of fluoride. Thus, the potential for developing a relatively minor unesthetic condition must be weighed against the potential for reducing dental disease.