Fluctuations in public water fluoride level in Bauru,Brazil

Objectives: The aim of this study was to monitor the quality of public water supply fluoridation in Bauru, in the state of São Paulo, Brazil. Methods: Water samples collected three times a week during four weeks in 20 areas of distribution of water were supplied by the City Water Department of Bauru, São Paulo, Brazil. fluoride was analyzed using the ion‐specific electrode (Orion model 9409) after sample buffering with an equal volume of TISAB II. Data were compared to fluoride concentration reported by City Water Department. Results: Fluoride content ranged between 0.01 ppm and 9.35 ppm (n=240). There was great variation among the different areas of distribution of water, as showed by the Levene test (P<0.01). Kruskal‐Wallis test showed a statistically significant difference in mean fluoride concentration among different areas (P<.001). Mean fluoride concentration was less than the optimum concentration (0.8 ppm) in 89 percent of samples. The values reported by the City Water Department were always higher than the analyzed fluoride concentrations. Conclusions: Based on the results from this study, more rigorous surveillance and monitoring of water fluoridation in Bauru is recommended.     

High concentrations of fluoride and boron in drinking water wells in the Muenster region--results of a preliminary investigation

In 1998, two cases of severe dental fluorosis in schoolchildren occurred in the Muenster region. These cases took place in one household, where fluoridated toothpaste, fluoridated salt, and fluoride tablets were consumed. Furthermore, the family used drinking water from its private well only. Analyses of the well water ordered by local health officials revealed very high amounts of fluoride, boron, and other electrolytes. This unusual combination of high amounts of fluoride and boron could also be found in the water of a great number of other private wells that are the only source for drinking water in this rural region of the Muensterland. Anthropogenic sources could be excluded. Because of this, the results of the water samples were collated to the specific geological situation in this area. In the Muenster region there are marl layers of the chalk era covered with quarternary sediments. The quarternary sediments are up to 10 to 20 metres thick and they usually conduct the groundwater. The marl contains high concentrations of fluoride and boron. In some places the groundwater has contact with these layers. To check the amount of fluoride and boron in the groundwater, indicator values were sought, which can give a hint of high contents of these trace elements. In this study the conductivity and acidity were identified as possible indicators of a high amount of fluoride and boron in the drinking water in this specific region. To work economically and efficiently, the drinking water should be checked for fluoride and boron on a regular basis only when these values are extraordinarily high. In the case of high concentrations, especially of fluoride, in the drinking water the persons concerned should be informed about their potential health risk, giving them the opportunity to optimise the total daily intake of fluoride.     

Potential of 4 per cent silver fluoride to induce fluorosis in rats: clinical implications

The Health Department in Western Australia uses a 40 per cent silver fluoride (AgF) solution for prevention and treatment of dental caries in children. Analysis of this solution has revealed high fluoride concentrations (75,000-120,000 mg/L), raising concerns of potential toxicity and prompting investigation of clinical protocols utilizing low-strength AgF in an animal model. A single topical application of 4 per cent AgF solution to Sprague-Dawley rats resulted in moderate to severe localized fluorosis in 24 per cent of animals. In a second experiment, caries was induced in rats aged 19 days; six weeks later, between one-four carious molar teeth from each rat were treated with 4 per cent AgF (atraumatic technique). A generalized form of fluorosis developed in the continually growing incisors of less than 10 per cent of animals which had one or two carious teeth treated, and in 70-90 per cent of rats which received AgF to either three or four carious teeth. These results confirm the potential of a 4 per cent AgF solution to induce fluorosis and support previous recommendations that AgF at its empirical concentration of 40 per cent should be withdrawn from clinical use.     

氟骨症患者氟蓄积与骨畸形程度相关性研究

目的:探讨氟骨症患者体内氟蓄积与骨畸形程度的相关性研究。方法:暴露组在内蒙古呼和浩特市托县饮水氟含量高于正常的5个自然村随机选取确诊的氟骨症患者70例。并根据《地方性氟骨症临床分度》进行分度。对照组:在呼和浩特市郊区长期居住的,饮水含氟量正常的人群中随机选取70例。两组人群要求年龄在25~55岁,无其他疾病史者。检测两组血Ca2 、P3 、Mg2 和ALP及血脂TC、TG指标,并用T检验及多样本方差进行数据分析。结果:暴露组与对照组血ALP及血脂TC、TG检测指标具有显著差异(P<0.01),血Ca2 、P3 、Mg2 无显著差异(P>0.05)。氟骨症患者骨畸形程度的三度分度中I度与Ⅱ、Ⅲ度血中ALP比较具有统计学意义(P<0.05),而Ⅱ、Ⅲ度与Ⅲ度之间无统计学意义(P>0.05)。结论:长期摄取过量的氟对人体血液生化中血ALP及血脂代谢TC、TG有明显的影响,血中ALP差异间接反映了氟蓄积的程度。氟骨症患者骨畸形程度与体内氟的蓄积无正相关。     

Fluorosis risk in grade 2 students residing in a rural area with widely varying natural fluoride

OBJECTIVES: This pilot study was performed to determine the prevalence of dental fluorosis and the association between fluorosis and a number of risk factors in a group of second grade students in a rural, non-fluoridated area of Ontario, Canada. METHODS: Of 1739 students screened during routine health surveillance, 1367 had erupted maxillary central incisors. Fluorosis was scored on these children using the Tooth Surface Index of Fluorosis (TSIF). A fluoride exposure questionnaire and water sample vial was sent home from school with each child. RESULTS: Valid responses were obtained for 752 children (55%). The prevalence of fluorosis in respondents was 23.3%, with 4.9% scoring TSIF of 2 or more. In bivariate analysis, several variables were significantly associated with the prevalence and/or severity of fluorosis. These included: water fluoride concentration, breast-feeding duration, professionally applied topical fluoride, fluoride supplement use, bottle-feeding, fluoridated mouthwash use, and early parental toothbrushing with toothpaste. In logistic regression analysis limited to children living at the current residence for 4 years or more, only four variables had significant independent effects. These were water fluoride concentration, breast-feeding duration, fluoride supplement use, and fluoridated mouthwash use. CONCLUSIONS: These findings indicate that fluorosis is an important concern in non-fluoridated areas. Fluoride supplements should not be recommended unless an independent home water test is performed. Breast-feeding for 6 months or more may protect children from developing dental fluorosis in the permanent incisors.     

西安市古汉城遗址高氟区儿童氟牙症现况调查

【目的】 了解西安市古汉城遗址区儿童地方性氟中毒现状,为饮水改造工程的实施提供科学依据。 【方法】 对古汉城遗址内11个村集中式饮用的井水用氟离子选择电极法对水氟含量进行测定,并用Dean氏法检查8~12岁儿童氟牙症患病情况。 【结果】 在汉城乡11个高氟村,检查8～12周岁儿童457人,检出氟牙症患者75人,检出率为16.4%,极轻患者57人(检出率为12.2%),轻度患者18人(检出率为3.9%),未见中度和重度氟牙症出现。 【结论】 古汉城遗址内8~12岁儿童氟牙症检出率16.4%。在保存古汉城遗址完整的同时,政府应加大力度进行饮水改造措施的实施,从根本上解决遗址内居民的饮水状况,从而有效地控制地方性氟中毒的流行。     

重庆市燃煤污染型地方性氟中毒防治调查结果分析

目的了解重庆市燃煤型氟中毒病区的防治现状,为燃煤型氟中毒的防治决策提供科学依据。方法采用分层整群抽样的方法,运用统一设计的居民防治现状调查问卷,对抽查的病区村居民进行问卷调查。调查内容包括病区居民的燃料结构、炉灶使用情况和耕种方式等,计算改炉改灶的合格率、改炉改灶的正确使用率、炉灶的报废率。运用Dean's法检查所有调查村8～12岁儿童氟斑牙患病情况,计算氟斑牙的患病率、氟斑牙指数、缺损率。按照《地方性氟骨症的临床诊断标准》,调查所有病区村16岁及以上的成人,计算氟骨症患病率。结果本次共调查8个病区县9个乡镇12个村4512户,其中使用煤作为燃料的户数为4408户,占97.70%。使用炉灶的户数为4405户,使用率达到97.63%,正确使用率为47.92%。改炉正确使用率为61.77%,报废率为0.38%。改灶正确使用率为46.36%,报废率为0.21%。8～12岁儿童氟斑牙检出率为72.88%,缺损率为8.16%,氟斑牙指数为1.29。16岁及以上氟骨症检出率为1.92%。结论通过20年的以改炉改灶为主的综合性防治,重庆市燃煤型氟中毒病情逐渐减轻,病区类型和数量逐渐减少,说明以改炉改灶为主的综合性防治措施效...     

The association between osteocalcin gene polymorphism and dental fluorosis among children exposed to fluoride in People's Republic of China

Excessive fluoride intake has been shown to affect dentin and cementum mineralization throughout life. Some studies indicated that a HindIII polymorphism, of osteocalcin (OC) gene, was associated with bone metabolism-related diseases. Therefore, it is possible that the variation in OC genotypes will be associated with dental fluorosis (DF) status and/or serum caciotropic hormone level. A case-control study was conducted among children aged 8–12 years in Henan Province, PR China to investigate the association between dental fluorosis, serum calciotropic hormone level, and polymorphisms in the OC gene. HindIII polymorphism in OC gene was genotyped using the PCR-RFLP procedure. OC and calcitonin (CT) level in serum was detected using radioimmunoassay. No significant difference was observed for OC HindIII genotypes among the cases with dental fluorosis, the controls from endemic fluorosis area (EFA) and the controls from non-endemic fluorosis area (NEFA). A significant negative correlation was observed between serum calcium and OC level. No significant relationship was found between OC HindIII polymorphisms and the level of OC and CT. In conclusion, OC HindIII polymorphisms may not be a useful genetic marker for differential risk of dental fluorosis among children in PR China.     

Perceptions of adolescents and young people regarding endemic dental fluorosis in a rural area of Brazil: psychosocial suffering

Severe dental fluorosis is endemic in some rural areas of Brazil. This paper describes the psychosocial consequences of this condition and how it has affected the self-esteem of adolescents and young people in a rural area in Brazil. Semi-structured, face-to-face interviews were carried out with 23 adolescents and young people affected by severe dental fluorosis and 14 of their teachers. The study revealed the affected individuals were embarrassed to smile at strangers due to a presumed association between fluorosis and a lack of dental hygiene. Further findings include conflicts between affected and non-affected students at school, problems in pursuing a romantic relationship and uncertainties regarding a professional future. Disbelief and scepticism were observed regarding the ethical position that science can offer a solution to the problems stemming from the disease. Lesions from severe dental fluorosis appear to be a stigmatising factor and have contributed toward suffering and self-exclusion among an entire generation of adolescents and young people.     

Diagnosing dental caries in populations with different levels of dental fluorosis

The aim of this study was to assess the reliability of the Nyvad visual–tactile caries-diagnostic criteria when used among children who have been lifelong residents in areas with 'optimal' or low concentrations of fluoride in the drinking water. In each of two areas with drinking water fluoride concentrations of 0.3 and 1.1 ppm (0.3 and 1.1 mg/l) fluoride, respectively, 150 children were clinically examined twice, 2 wk apart, for dental fluorosis, using the Thylstrup-Fejerskov index (TF index), and for dental caries using the Nyvad visual–tactile caries criteria. The prevalence of dental fluorosis was 45% in the 1.1 ppm fluoride area and 21% in the 0.3 ppm fluoride area. When the results of the duplicate caries recordings were compared at the surface level, only minute differences were observed in the percentage agreement (91.7 and 90.7%, respectively) and in the kappa values (0.73 and 0.72, respectively). When individual DFS counts were compared across examinations using Bland–Altman plots and estimation of prediction intervals for the differences, we observed a greater variability of the differences between recordings among children from the low-fluoride area. Contrary to our expectations, a pronounced dental fluorosis background did not reduce the reliability of the caries recordings, which appeared to be slightly less reliable at very low levels of dental fluorosis.