Mild Fluorosis Research Articles

Fluorosis in relation to fluoride levels in water in central Nigeria

Abstract– Objectives: This study was conducted to examine the prevalence of dental fluorosis in relation to fluoride levels in water among children aged 12–15 years in the states of Plateau and Bauchi, Nigeria. Methods: Children (N=203) were examined using WHO criteria. The children were from two schools and permanent residents of the communities in which the schools are located (Tilden Fulani and Kanadap). Intra-examiner reliability for determining fluorosis scores was 80%. Results: Fluoride levels in the water ranged from 0.0–0.4 mg/L. Prevalence of dental fluorosis in the sample was 51%. Forty-one percent had very mild fluorosis, 7% had mild fluorosis and 3% had moderate to severe fluorosis. The lowest DMFT was observed in the school where the fluoride level of the water ranged between 0.0 and 0.4 mg/L, and in the group with very mild fluorosis. Conclusion: Fluoride levels in water for central Nigeria were appropriate for oral health. In the areas where the children were permanent residents, factors other than the fluoride levels of the water contributed to the severity of dental fluorosis.

Fluorosis in relation to fluoride levels in water in central Nigeria

This study was conducted to examine the prevalence of dental fluorosis in relation to fluoride levels in water among children aged 12-15 years in the states of Plateau and Bauchi, Nigeria. Children (N = 203) were examined using WHO criteria. The children were from two schools and permanent residents of the communities in which the schools are located (Tilden Fulani and Kanadap). Intra-examiner reliability for determining fluorosis scores was 80%. Fluoride levels in the water ranged from 0.0-0.4 mg/L. Prevalence of dental fluorosis in the sample was 51%. Forty-one percent had very mild fluorosis, 7% had mild fluorosis and 3% had moderate to severe fluorosis. The lowest DMFT was observed in the school where the fluoride level of the water ranged between 0.0 and 0.4 mg/L, and in the group with very mild fluorosis. Fluoride levels in water for central Nigeria were appropriate for oral health. In the areas where the children were permanent residents, factors other than the fluoride levels of the water contributed to the severity of dental fluorosis.

Characterization of fluorosed human enamel by color reflectance, ultrastructure, and elemental composition.

Mature fluorosed human enamel has been described as a subsurface enamel hypomineralization, with porosity increasing relative to the degree of fluorosis. The purpose of the current study was to quantitatively measure the color of the fluorosed enamel by light reflectance, and to further characterize the enamel by scanning electron microscopy. Teeth with varying degrees of fluorosis were obtained and divided in groups of mild, moderate and severe fluorosis using Dean's index for fluorosis. The color of the labial enamel surface was measured using a Minolta Chroma Meter CR241 (Minolta, Ramsey, N.J., USA). The teeth were further characterized for elemental composition using an energy-dispersive spectrometer, and imaged in both secondary and backscattered electron modes. The results of this study showed that the moderately and severely fluorosed enamel contained an uneven distribution of areas which were more electron-absorbent with a relatively increased carbon content. The changes in the physical characteristics of the teeth could be quantitated by measurements of light reflectance. The color of the teeth was significantly different between groups, with all groups significantly different than normal.

Epidemiologic Indices for Measuring the Clinical Manifestations of Dental Fluorosis: Overview and Critique

Several indices have been used to describe the clinical appearance of dental fluorosis. The purpose of this paper is to describe and compare the three principal ones in use today: those developed by Dean (1934, 1942), Thylstrup and Fejerskov (1978), and Horowitz et al. (1984). A recent index (Fluorosis Risk Index) developed by Pendrys (1990) is also included in this review. The continued use of Dean's classification system and derived index (CFI) for more than a half century is testimony to its simplicity and utility. The index has been criticized because the unit of analysis is the person, because criteria are unclear for some categories, or that they lack sensitivity, particularly for severe fluorosis, and because of the way in which data are summarized and reported. The Thylstrup and Fejerskov Index is appealing to clinicians and epidemiologists alike in that it corresponds closely to histological changes that occur in dental fluorosis and to enamel fluoride concentrations, thereby having biological validity. The TSIF described by Horowitz et al. makes a useful contribution because it provides clearer diagnostic criteria and provides for an analysis based on esthetic concerns. The Fluorosis Risk Index appears to be particularly useful for analytical epidemiologic studies, because it is designed to permit a more accurate identification of associations between age-specific exposures to fluoride and the development of dental fluorosis. All three indices in common use today provide useful indices for the study of dental fluorosis. The utility of the Fluorosis Risk Index will be determined as it receives wider use. The selection of one of these indices for use in an epidemiologic study depends in large measure on the purpose of the study. Research needs to continue on the validity of these indices, particularly for mild fluorosis, and on the public's perception of the cosmetic appearance of teeth with different severity levels of fluorosis.

Perceptions of Dental Fluorosis

Mild dental fluorosis has long been accepted as a side-effect of water fluoridation and, more recently, has been recognized as a consequence of the use of other fluoride-based caries-preventive strategies. Traditionally, dental health professionals have not seen this as being of public health importance, but members of the public have not been asked their opinion. The purpose of the present study was to gather the opinions of lay groups concerning the appearance of the teeth of children with various degrees of fluorosis. Twenty-eight children, born in 1978, who had earlier participated in a study of fluorosis in Perth (Western Australia), allowed 110 observers to look at their upper central incisors under good viewing conditions. Fluorosis in these teeth ranged from TF score 0 (no fluorosis) to TF score 3. The observers were university students, parents, public servants, or dentists. They responded to statement items about the appearance of the teeth. The results, based on just over 3000 responses, showed that lay and dental observers could distinguish between different fluorosis levels. In response to a statement that the teeth appeared pleasing, a large majority agreed when the TF score was 0, but agreement declined as the TF score increased; when the TF score was 3, most people disagreed. Similarly, observers felt that the appearance would increasingly embarrass the child as the TF score increased. Observers, except the dentists, tended to feel that higher TF scores indicated neglect on the part of the child.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of enamel defects/fluorosis in fluoridated and non-fluoridated areas in Ireland.

Water fluoridation was introduced in Ireland in 1964 and in recent years the availability of fluoride from other sources had increased. As part of a National Survey of Children's Health in Ireland Dean's and the DDE indices were used to determine the prevalence of enamel fluorosis/defects in 8- and 15-yr-old children in fluoridated and non-fluoridated areas. Over 94% of the children examined in all areas were regarded as having normal enamel, as defined by Dean's index, the remainder showing evidence of either questionable, very mild or mild fluorosis. Between 52% and 63% of the children had one or more teeth affected by enamel defects when measured by the DDE index. The prevalence of enamel fluorosis/defects was similar in children living in fluoridated and non-fluoridated areas but the prevalence of diffuse opacities (DDE) was higher in the fluoridated areas.

Benefits and risks of fluoride supplementation: Caries prevention versus dental fluorosis

To assess the risks (dental fluorosis) and the benefits (caries prevention) of fluoride (F) tablets and F toothpaste, we surveyed 2003 schoolchildren aged 5-20 years old (mean = 10.82, SD = 3.40). Children were scored for dental caries by means of the decayed, missing, filled teeth index (DMFT index). Frequent use of F toothpaste (toothbrushing frequency) is poorly linked to caries (Spearman r = 0.05, P = 0.02) and dental fluorosis (r = 0.05, P = 0.03). Children who use F tablets regularly and appropriately exhibit mild fluorosis more often than non- or occasional users (odds ratio = 9.58), and have a mean DMFT index 50% lower than other children. We conclude that using F tablets is an effective means of preventing caries. When used appropriately in non fluoridated areas, using F tablets results in minor damage.

Fluoride in the prevention of caries in the preschool child

The use of fluorides has benefited greatly the dental health of preschool children. Water fluoridation cuts caries by half in the deciduous dentition as it does in the permanent dentition. In the absence of water fluoridation, fluoride dietary supplements can be used and are effective. For practical reasons it may be useful to limit their use to those at risk from caries and those seen to be prone to caries. There has been some concern over links between early use of fluoride toothpastes and the occurrence of very mild fluorosis. Although this is not perceived as a problem by parents or the community, it is prudent to recommend that parents clean their children's teeth with a pea-size amount of toothpaste. Fluoride varnishes are effective and are useful for preventing caries in young children.

Fluorosis and dental caries in 6–8‐year‐old children in a 5 ppm fluoride area

Fluorosis levels and caries prevalence were evaluated in 152 children aged 6-8 yr residing from birth in an area with 5 ppm fluoride in the drinking water. Sixty-two of the subjects had mild fluorosis in both primary and permanent dentition, 31 were defined as moderate, and 4 cases had no signs of fluorosis; 14 cases had a more severe fluorosis level in the primary dentition as compared to 41 cases in which fluorosis was more severe in the permanent dentition. More primary dentitions were free of fluorosis in females than in males (P less than 0.05). No differences between males and females were found in the permanent dentition fluorosis. The decay rate in the permanent dentition gradually increased with increasing fluorosis severity, a finding not observed in the primary dentition. Reasons are discussed for the lower fluorosis level in the primary dentition and the more severe fluorosis in older age groups as well as the fluorosis severity difference by gender.

Risk factors for dental fluorosis in a fluoridated community.

We conducted a case-control study to determine the sources of fluoride which are particular risk factors to dental fluorosis. Cases and non-cases were identified by the screening of 8-, 9-, and 10-year-old schoolchildren in the fluoridated community of East York, Ontario. Parents were interviewed about the child's first five years of residence and about diet and preventive caries practices. The Mantel-Haenszel odds ratio and associated chi-square tests were used to assess the association of fluorosis with several potential sources, controlling for other sources of fluoride and mother's education. The prevalence of mild fluorosis [1-4 on the Thylstrup and Fejerskov (1978) Index] was 13%. Those who brushed their teeth before the age of 25 months had 11 times the odds of fluorosis compared with those beginning toothbrushing later; prolonged use of infant formula (greater than or equal to 13 months) was associated with 3.5 times the risk of fluorosis, compared with no, or shorter duration of, formula use. We estimate that these factors were responsible for 72% and 22%, respectively, of the cases in our population. Dental fluorosis is not a public health problem in East York, but parents should be advised to supervise toothbrushing by children under 2 years of age.

Fluorosis and caries prevalence in a community drinking above-optimal fluoridated water.

Fluorosis levels and caries prevalence were evaluated in 182 adolescents aged 15-16 yr residing from birth in an area with 5 ppm fluoride in the drinking water. The mean number of surfaces affected by caries in the total study population was 5.46 DMFS. The teeth most susceptible to caries were the first molars. The prevalence of fluorosis was 100% with 53 subjects demonstrating mild fluorosis (according to Dean's index), 83 demonstrating moderate fluorosis, and severe fluorosis diagnosed in 46 subjects. A statistically significant positive association was found between caries prevalence and fluorosis; the more caries experienced, the more severe the fluorosis level. Boys experienced significantly higher fluorosis levels than girls. Further research will investigate the possible variables which may explain this difference in fluorosis by sex.

Streptococcus mutans and dental caries in urban and rural schoolchildren in Thailand.

Two groups of Thai schoolchildren aged 11-13 yr were examined for dental caries, dental fluorosis and Streptococcus mutans. One hundred children lived in an urban district, Bangkok, and 71 children in a rural district, Petchaboon. Saliva samples were analyzed for S. mutans by the spatula method. The fluoride content of the drinking waters was also determined. The prevalence of caries, diagnosed according to WHO, was 89% in Bangkok and 18% in the rural district. Mean DMFT was 3.46 and 0.38 respectively. S. mutans was found in 98% of the urban children and in 82% of the rural. The differences in distribution between S. mutans and DMFT classes were statistically significant for the total sample. Mild fluorosis was present in some of the rural children.

Effect of long-term administration of fluoride on the levels of EDTA-soluble protein and gamma-carboxyglutamic acid in rat incisor teeth.

EDTA-soluble material, extracted from incisor teeth of rats given 50 ppm fluoride (NaF) in drinking water ad libitum from conception to age nine wk, contained significantly higher levels of protein (P less than 0.01) and gamma-carboxyglutamic acid (P less than 0.01) than did similar material from control rats. Tooth fluoride levels indicated that the incisors were mildly fluorosed. Analysis of these data indicates that mild fluorosis of rat incisor teeth involves not only the characteristic disturbances of pigmentation and mineral structure but also some alteration of the matrix protein.

Swallowed Toothpaste—A Danger or Not

How concerned should we pediatricians be about the fact that young children frequently swallow fluoridated dentifrices while brushing their teeth? The recent recommendation of the Academy's Committee on Nutrition for a decrease from 0.5 to 0.25 mg/day for children less than 2 years of age was "to reduce the possibility of mild fluorosis."1 According to the American Dental Association, the usual amount of dentifrice used on a toothbrush contains approximately 1 mg of fluoride (personal communication from American Dental Association to E. J. Beadle, DDS, 1980).

Letters to the Editor

There is presently some difficulty with fluoride supplementation for a child in the first year of life. The American Academy of Pediatrics regimen for supplemental fluorides produced mild fluorosis in some subjects (Aasenden R, Peebles IC: Arch Oral Biol 19:321-326, 1974), and infant formulas may presently have variable amounts of fluorides. See Table in the PDF File This regimen is needed only in areas that do not have optimally fluoridated water, and when infants are ingesting commercial infant formula, no supplementation may be necessary.

Dental findings in high‐fluoride areas in Ethiopia

A survey comprising 478 children aged 6-7 years and 13-14 years was conducted in high-fluoride areas (Wonji, 12.4 parts/10(6) F- and Awassa, 3.5 parts/10 F-) in the Rift Valley in Ethiopia. Dental fluorosis was found in 99% of the 6-7-year-old groups. Very mild to moderate fluorosis dominated in the primary teeth and moderate to severe fluorosis in the permanent teeth. All 13-14-year-old children born in Awassa of Wonji had fluorosis, mainly in the moderate to severe form. Eighty-four percent of the 13-14-year-old children not born in the area had fluorosis, mainly in the very mild form. The most severe fluorosis was seen in the last erupting teeth, but moderate fluorosis was also seen in primary incisors, indicating placental transfer of fluorides. Teeth with moderate and severe fluorosis more frequently had dental caries than teeth with no or very mild and mild fluorosis. The average DMFT was 2.46 +/- 2.34 in Wonji and 1.69 +/- 1.88 in Awassa. The average dft was 0.32 +/- 0.80 in Wonji and 0.40 +/- 0.96 in Awassa. Gingivitis was seen in 97% of the children and the average OHI-S was 1.94 +/- 0.71.

Early supply of fluoride and enamel fluorosis

A study of enamel fluorosis in 1,094 children was carried out in areas with a water fluoride content of from less than 0.2 mg/l with and without supplementary fluoride, to 2.75 mg/l. The fluorosis was correlated with different infants diets and also with the calculated supply per kilo body weight. As in cattle, 0.1 mg F/kg body weight daily appears to cause fluorosis. This dose may for example be reached with water-diluted gruel powder in low-weight infants with high consumption in low F areas, in normal weight infants in 0.8 areas, and also in high-weight infants in 1.2-1.5 areas. The resultant fluorosis is very mild or mild and not disfiguring. Enamel fluorosis can be avoided or minimized in areas with up to at least 1.2 mgF/l water if F-supply, e.g. water-diluted gruel and/or supplementary fluoride, is not commenced until 6 months of age when body weight is higher. With a water fluoride content of 2.75 mg F/l a very mild fluorosis is difficult to avoid also with normal water consumption during the 1st year of life.