Severity of dental caries among 12-year-old Sudanese children with different fluoride exposure.

The aim of this study was to assess the effect of fluoride on the severity of caries among children exposed to different concentrations of fluoride in the drinking water and living in rural areas in the Sudan. Permanently resident schoolchildren (n = 299) aged 11-13 years from three villages were clinically examined under field conditions. The caries criterion was teeth in need of extraction or extracted; only molars were recorded. Dental fluorosis was scored on all buccal tooth surfaces by the Thylstrup and Fejerskov index. The fluoride concentrations of the drinking water were assessed in samples (n = 25) collected from wells and households. Predictors of caries were assessed by logistic regression analyses. There was no significant difference regarding age and gender distribution between the areas (P > 0.05, df = 2, Kruskal-Wallis test). The socio-economic conditions in these villages were presumed to be equal. Significantly different fluoride concentrations in the drinking water were verified by the severity of dental fluorosis. Children in Abu Delaig, drinking water with 1.0-2.0 mg fluoride/L (median = 1.8), had significantly higher caries prevalence (21% versus 8%) than in a 0.4 mg fluoride area. Area was the only significant predictor for caries; odds ratio 3.7 for children in Abu Delaig compared with the low fluoride area. There was no difference in caries prevalence between the lowest and the highest fluoride (2.9 mg) area. This study failed to demonstrate an effect of fluoride in drinking water on caries experience when the end point was molars indicated for extraction or missing because of caries.

Evidence for reversal of the caries decline among Norwegian children.

OBJECTIVE: The purpose of the present study was to report on caries status and to explore possible reasons for changes in caries experience among 5- and 12-year-old Norwegian children. DESIGN: National cross-sectional and time trend study. METHODS: Aggregated data from the Public Dental Services and from official statistics were used. Information was available on the total number of children, the proportion receiving treatment, sale of fluoride tablets, socio-economic background, caries prevalence and dmft/DMFT scores. RESULTS: The prevalence of caries among 5-year-olds reached a low of 30.4% in 1997 and increased to 38.9% in 2000. The mean dmft scores increased from 1.1 to 1.5. Conversely, the prevalence of caries among 12-year-olds decreased from 55.4% in 1997 to 52.2% in 2000 and the mean DMFT score from 1.7 to 1.5. Bivariate analyses at county level revealed significant associations, which for the most part disappeared in multivariate analyses. The sale of fluoride tablets had a significant effect on caries prevalence among 5-year-olds in 1998, in 1999 and in 2000. Infant mortality was associated with the dmft score in 1999. The only consistently significant predictor of caries experience at 12 years of age was caries prevalence at age 5. CONCLUSIONS: There has been a highly significant increase in caries experience among 5-year-olds (P < 0.001) and a levelling off among 12-year-olds over the past 3 years. Considering the association between caries prevalence at age 5 and caries experience at 12 years of age, there is a need for reassessment of the caries preventive programmes for children in Norway.

Dental caries among 10- to 14-year-old children in Ugandan rural areas with 0.5 and 2.5 mg fluoride per liter in drinking water.

The purpose of this study was to report on dental caries among Ugandan children residing in rural areas with either a low or high fluoride concentration in the drinking water, and to assess factors associated with caries. A random sample of 481 children aged 10-14 years was selected from Mpondwe (n = 81) and Kyabayenze (n = 82) in the Kasese district with 0.5 mg and from Mutolere/Kagera (n = 163) and Kabindi (n = 155) in Kisoro with 2.5 mg fluoride/l in the drinking water. The children were examined for caries using the DMFT index as described by the World Health Organization in 1987. The mean DMFT was 0.34 in the whole material. In one low fluoride area, Kyabayenze, all children were caries-free compared to 75% to 86% in the other areas. In Kyabayenze, tea with sugar was taken significantly less frequently than in the other low-fluoride area. In the high-fluoride district, age and consumption of tea with sugar were positively and significantly correlated with caries. Multivariate analyses showed age to be the only significant risk indicator.

Caries decline before fluoride toothpaste was available: earlier and greater decline in the rural north than in southwestern Norway.

The purpose of this study was to evaluate factors related to caries in 6-17-year-olds in 2 groups of Norwegian counties between 1966 and 1983. The average number of surfaces filled and permanent teeth extracted due to caries declined in the 4 northern counties from 1967. An increase was recorded in the 7 southwestern counties until 1971, then a decline. In the 1960s significantly more surfaces were filled and teeth extracted in the north compared to the southwest. Based on intra-county comparisons, the decline in surfaces treated was greater in the north between 1967 and 1983; 5.4 +/- 0.4 vs 3.7 +/- 0.7, P < 0.01. The averages were 1.9 surfaces treated in the north and the southwest in 1983. Higher infant mortality, lower percentage of people with completed senior secondary education, and more inhabitants per doctor and per dentist in the north indicate a less favorable situation than in the southwest. School-based fluoride programs had been implemented in both groups from the mid-1960s and around 60% participated when fluoride toothpaste became freely marketed in 1971. More fluoride programs and more fluoride tablets were available to children in the north; this may indicate a preventive attitude among dentists. The decline of caries started at different times in different parts of Norway. In the rural north with the most unfavorable situation, the decline was greater and started years before fluoride toothpaste came on to the market. The early decline may partly be ascribed to the school-based fluoride programs, the continued decline to several factors.

Assessment of the validity and consequences of different methods of expressing the severity of dental fluorosis in a subject.

The aim was to assess the validity and consequences of different methods of expressing severity of dental fluorosis in a subject. The analyses were based on Ugandan children (n = 481), aged 10-14 years, with life-long consumption of drinking water with either 0.5 or 2.5 mg fluoride per liter. Fluorosis was assessed using the Thylstrup and Fejerskov (TF) index. All children (n = 219) with 28 teeth and fluorosis on at least 1 tooth pair were selected to test methods of expressing fluorosis, e.g. the TF score on the most severely affected tooth, a maxillary central incisor, the median and the mean scores. A test group (n = 40), the 10 most and the 10 least severely affected children in each district, was used to evaluate the methods and a reference group (n = 179) to confirm or refute the findings in the test group. To evaluate consequences of the different methods of expressing severity of fluorosis in a subject, children from the low (n = 130) and the high fluoride (n = 132) districts not included in the test or reference group formed the community comparison groups. Comparison between the median (gold standard) and mean scores showed a significant deviation in the reference group only. Most of the partial recording methods, such as the score for the most severely affected tooth, were significantly and systematically higher than the median. While for all recording methods the median score was zero in both communities, the distribution of the subjects according to severity differed significantly between the communities.

Age as a determinant of severity of dental fluorosis in children residing in areas with 0.5 and 2.5 mg fluoride per liter in drinking water.

The purpose of this study was to investigate the influence of age on the severity of dental fluorosis in children exposed to drinking water with either low or high fluoride concentrations. The children selected for this study were aged 10-14 years, with 28 permanent teeth and at least 1 tooth pair with fluorosis. The children were permanent residents of districts in western Uganda with either 0.5 mg (n = 33) or 2.5 mg fluoride/l in drinking water (n = 186). All vestibular tooth surfaces were examined for fluorosis using the modified Thylstrup and Fejerskov (TF) index. In the high fluoride community, the proportion of teeth per child with TF scores > or = 4, and > or = 5 was significantly higher among children aged 13-14 years compared to those aged 10-12 years. Children's chronological age correlated positively and significantly with the median TF scores for all teeth, including early erupting (first molars and incisors) and late erupting teeth (canines, premolars and second molars). In linear regression analyses, the median TF score for all teeth, as well as for early erupting and late erupting teeth, increased significantly with age. On the other hand, in the low fluoride community there was no significant association between age and the severity of fluorosis. This study showed a significant increase in the severity of fluorosis with increasing age in a high fluoride community, whereas no change in severity with age was observed in a low fluoride community.

Weaning food and magadi associated with dental fluorosis in Northern Tanzania.

A cross-sectional study of 143 children aged 10-14 years was carried out to identify factors associated with the severity of dental fluorosis in 2 areas (Moshi/Kibosho: n = 63/80) with fluoride (F) concentrations < 0.4 mg F/L in the drinking water. Dental fluorosis was recorded under field conditions using the Thylstrup and Fejerskov index (TFI). The score on tooth 21 was used to indicate the severity. The prevalence of dental fluorosis in Moshi at TFI score > or =1 was 60% and at TFI score > or =5 it was 10%. The corresponding values in Kibosho were 100% and 34%, respectively. Background variables pertained primarily to the child's first 6 years of life. In Moshi and Kibosho, 65% and 97% of children, respectively, used magadi, a fluoride-containing food tenderizer. In Moshi, the risk of having TFI score > or =2 was significantly higher among users of magadi (odds ratio (OR) = 5). Kiborou, a traditional homemade weaning food (porridge) cooked with magadi, was used only in Kibosho. Users of kiborou (36%) were at significantly higher risk (OR = 3) of developing fluorosis at severity TFI > or =4 than the users of lishe, another type of weaning food. All children in Moshi and 64% in Kibosho used lishe, which is cooked without magadi. Magadi and kiborou were significant risk indicators. Thus, it seems that the unexpectedly high prevalence of dental fluorosis and the observed differences in fluorosis prevalence and severity may be partly explained by F exposure from magadi.

Some factors associated with the caries decline among Norwegian children and adolescents: age-specific and cohort analyses.

The purpose of this study was to evaluate factors related to the caries decline in children between 1966 and 1983. The decline started in the late sixties for the 8- to 11- and the 17-year-olds, and after 1971 for the remaining age groups. Regression analyses confirmed a significantly different start of the decline. Fluorides in school-based programmes, lozenges, and toothpaste, as well as education and sale of antibiotics were significantly (p< or =0.01) related to the caries decline in partial correlation analyses. Fluoride toothpaste was only significantly related to the decline in the last part of the period of observation. Supervised fluoride rinsing and brushing programmes at school may explain most of the decline before 1971. The later decline may be related to all fluoride agents and to education. Use of fluorides and other preventive efforts aimed at pre-school children may have contributed to the continual decline in the number of fillings in the permanent teeth of the youngest cohorts.

An attempt to explain why Tanzanian children drinking water containing 0.2 or 3.6 mg fluoride per liter exhibit a similar level of dental fluorosis.

The aim of this study was to identify factors that might explain the similar level of prevalence and severity of dental fluorosis in two neighboring areas in Tanzania: Kibosho; 0.2 mg fluoride/l, n = 96 and Arusha; 3.6 mg fluoride/l in drinking water, n = 80. Subjects aged 8-16 years were examined for dental fluorosis using the Thylstrup and Fejerskov Index (TFI). Based on the score on the upper left central incisor, the prevalence was not significantly different between the communities (TFI > or = 1). The severity, however, was significantly higher in Arusha. The areas had different food habits, e.g., type of weaning food used, and the use of magadi, a fluoride containing salt. In Arusha, 99% of the children had been given lishe, which is a magadi-free weaning food. Conversely in Kibosho, 61% used lishe while 39% used the magadi-containing weaning food kiborou. Magadi was used as food tenderizer in 'adult food' by 98% in Kibosho and 45% in Arusha. Residential area and use of magadi explained 5% of the variance in TFI scores in inter-area analyses. In intra-area analyses, weaning food in Kibosho and use of magadi in Arusha had a significant effect, but the total explained variance was only 5 and 4%, respectively. Apart from fluoride in the drinking water, other sources of fluoride such as use of magadi in weaning food (kiborou) and in the adult food may partly explain the high prevalence and severity of dental fluorosis in the community with 0.2 mg fluoride per liter in the drinking water.

Dental variables associated with differences in severity of fluorosis within the permanent dentition.

The aim of this study was to assess the influence of age at start, duration, and completion of enamel formation, as well as of tooth-eruption age and enamel thickness on the severity of dental fluorosis within the permanent dentition. The material comprised Ugandan children (n = 219), aged 10-14 years, with 28 teeth and at least 1 tooth with fluorosis. The children were permanent residents in districts with either 0.5 mg or 2.5 mg fluoride/l in the drinking water. Fluorosis was assessed on the vestibular surfaces of all teeth using the modified Thylstrup and Fejerskov (TF) index. In order to relate fluorosis to the dental variables, the material was divided into a test group (n = 103), with fluorosis on all teeth, and a reference group (n = 116), with fluorosis on up to 27 teeth. The reference group was used to confirm or refute the findings in the test group. Paired comparisons showed significantly higher median TF scores for the late than for the early mineralizing and erupting teeth. In multiple regression analyses, the age at start, duration, and completion of enamel formation as well as tooth eruption was significantly related to the severity of fluorosis after controlling for enamel thickness (P < 0.05, n = 14). The effect (R2change) of the dental variables on the variation in severity of fluorosis within the dentition was in decreasing order: the duration of enamel formation, age at completion of enamel formation, tooth-eruption age, and the start of enamel formation.

Vegetarianism and dental fluorosis among children in a high fluoride area of northern Tanzania.

OBJECTIVE: The purpose of this study was to compare the prevalence and severity of dental fluorosis among vegetarian and nonvegetarian children and adolescents living in an area where dental fluorosis is endemic. DESIGN: An analytical cross-sectional retrospective study. SAMPLE AND METHODS: Children (n = 165) aged 6-18 years, from five schools in Arusha town were examined. The children had a life-long exposure to drinking water with 3.6 mg F/litre. The severity of dental fluorosis was assessed using the Thylstrup & Fejerskov Index (TFI). RESULTS: In the vegetarian group (n = 24), the prevalence of dental fluorosis (TFI score > or = 1) was 67%, while 21% had severe fluorosis (TFI score > or = 5). In the nonvegetarian group (n = 141) the prevalence of fluorosis and severe fluorosis was 95% and 35%, respectively. In bi-variate correlation analyses age, vegetarianism and a series of other factors related to childhood nutrition (meals per day, the use of home-made porridge, the use of fish, etc.) were significantly associated with the tooth prevalence of dental fluorosis (TPF, P < 0.05). Stepwise multiple linear regression analyses explained 30% of the variance in TPF; age 15% points and vegetarianism 13% points. Multiple logistic regression analysis showed that the risk of developing dental fluorosis was seven times higher among nonvegetarians than among vegetarians. CONCLUSION: The significantly lower prevalence and severity of dental fluorosis among the vegetarian group compared to the nonvegetarians would seem to be related to diet.

Caries and dental fluorosis in a 0.25 and a 2.5 ppm fluoride area in the Sudan.

The purpose of this study was to assess the caries prevalence of children living in areas with either 0.25 or 2.5 ppm fluoride in the drinking water, and to relate caries experience to the severity of dental fluorosis. The children, aged 6-16 years (mean 11.3 years), were lifelong residents of their rural villages. The severity of dental fluorosis in the maxillary central incisors, assessed by Deans index, was 1.4 +/- 0.9 (n = 59) and 2.3 +/- 0.9 (n = 65) in the 0.25 and 2.5 ppm areas, respectively. There was no significant difference in DMFT between children from the two areas (2.6 +/- 2.3 n = 59 versus 2.1 +/- 2.3, n = 65). In the low-fluoride area 75% of the children had decayed permanent teeth compared to 66% in the high-fluoride area. In the primary teeth, however, both the caries prevalence and the dmft were significantly lower in the 2.5 ppm area than in the low-fluoride area. Stepwise, multiple, linear regression analyses, including all children, showed a significant effect of age on DMFT (30% of the variance explained), but no explanatory effect of fluoride in drinking water, severity of dental fluorosis, or gender. Regression analyses based on children in the 2.5 ppm area alone, showed significantly higher DMFT by increased severity of dental fluorosis. In children with a mixed dentition (n = 66), there was no association between caries in the primary and permanent teeth.

Fluorosis of deciduous teeth and first permanent molars in a rural Kenyan community.

The severity and distribution of fluorosis in the deciduous dentition of 76 children in a low-income community near Nairobi were studied. Seventeen children comprised a low-F (fluoride) group (water less than 0.7 ppm F) and 59 a high-F group (water approximately 9 ppm F). The high-F group had scores greater than or equal to 5 in the Thylstrup & Fejerskov classification system for 29% of the deciduous tooth surfaces, compared with 7% in the low-F group. Comparison between the scores of the second deciduous and the first permanent molars showed no significant difference in the high-F group (p greater than 0.001), whereas the deciduous molar was significantly less severely affected in the low-F group (p less than 0.001). The deciduous molars of the two groups differed significantly (p less than 0.002), but not the permanent molars (p greater than 0.10). Early introduction of tea might have been a major contributor to the distributions of fluorosis, particularly in the low-F group.

Intake of fluoride and excretion in mothers' milk in a high fluoride (9 ppm) area in Kenya.

In 27 nursing mothers a study was made on breast milk fluoride (F) levels and the 24-h intake of F through foods and beverages. The daily F intake averaged 22.1 mg (range 9.5-37.2 mg); cooked food contributed 11.7 mg, water 4.5 mg and tea 5.8 mg. The breast milk F concentration averaged 0.033 mg/l (range 0.011-0.073 mg/l). No significant correlation could be established between the milk F level and the intake of F. The milk F level was, however, correlated positively to mothers' age and negatively to mothers' weight. It is concluded that the milk fluoride level was only moderately increased by the high intake of F, and that the children's intake of F through mothers' milk was negligible compared to the very high F intake through complementary foods and beverages.

An 11-year follow-up study of dental caries after discontinuation of school-based fluoride programs.

The purpose of the present study was to determine whether the caries-preventive effect of school-based programs with fluoride (F) mouthrinsing or toothbrushing was evident at the end of a post-treatment follow-up period of 11 years. Two groups of subjects examined at 14 years of age (born in 1960), who had participated in fortnightly F rinsing (n = 52) or in F brushing 4-5 times a year at school (n = 50), were re-examined radiographically and completed a questionnaire at age 25 years. A comparison group of 25-year-olds (n = 51) was also included. Analyses of variance showed that the benefits of participation in school-based F programs seem to have been lost. It appears that these caries-preventive programs have delayed rather than prevented caries and that F toothpaste and other caries-preventive efforts have been insufficient to avert a substantial caries activity during the follow-up period.

Continual highly significant decrease in caries prevalence among 14-year-old Norwegians.

The MFS of 14-year-old children in Lillehammer, Norway, were recorded in 1959, 1969, 1979, and 1984. The data were extracted from dental records of random samples of 76 children. The mean MFS was 34.1 in 1959 and 28.0, 13.8, and 7.5 the following years. The caries prevalence was reduced by 78% from 1959 to 1984. In 1959, 16.6 approximal surfaces were filled, but in 1984 only 1.3. Significantly fewer radiographically initial lesions were observed in 1984 than in 1979. The continual decrease in caries prevalence is related to various fluoride programs, fluoride dentifrices, decreased caries prevalence among preschool children, and an assumed decreased challenge.

Relationship between caries prevalence and incidence among adolescents.

The purpose of this study was 1) to determine the strength and direction of the association between caries prevalence at 13-14 years of age and subsequent caries increments and 2) to assess the goodness of fit of a multivariate model to caries increments from age 13 1/2 to 20. Two sets of data were used. The first consisted of treatment records for 114 children from an incremental dental care program. They were divided into high and low caries prevalence groups at ages 13 and 14 and 2-and 3-year caries increments were calculated. Unstandardized regression coefficients and Pearson's r were used to determine the relationship between baseline caries prevalence and subsequent caries increments. This relationship was consistently positive in the low prevalence group, but changed to negative in the high prevalence group. This change of direction is most likely attributable to saturation with regard to caries. The second material comprised 20-year-old military recruits for 90 of whom treatment records were available from age 13 1/2. Caries prevalence at 13 1/2 years of age was by far the most important predictor of caries increment from age 13 1/2 to 20. The multivariate model provided a good fit to the empirical data (R2 = 37.4%). It was concluded that the interpretation of the results of clinical and field trials of anticaries agents may be complicated due to a saturation phenomenon if adolescent subjects with high caries prevalence of baseline are used.