Longitudinal study of prevalence of enamel lesions in a fluoridated and non-fluoridated area

The aim of this study was to examine longitudinally the effect of water fluoridation on the prevalence of enamel lesions in children 7-18 yr of age. 93 children in Tiel (1 ppm F-) and 103 children in Culemborg (0.1 ppm F-) were examined every other year at 7, 9, 11, 13 and 15 yr of age. A supplementary examination was carried out when these children reached the age of 18. Children in Tiel had access to water fluoridation from birth. The total number of lesions, including enamel lesions, on the buccal as well as on the occlusal surfaces was approximately the same in both areas in children 15 and 18 yr of age. Approximal lesions were scored on standardized bitewing radiographs. A large proportion of enamel lesions could not be detected on radiographs. In a fluoridated area a high percentage of all lesions remain in the stage of enamel caries lesions. On buccal surfaces 93% and on approximal surfaces 86% of all lesions had not progressed into the dentin. In Culemborg these percentages were 65 for approximal as well as for buccal surfaces. At the initiation of lesions, at younger ages, only a small retardation of the process was observed, but caries progression beyond the stage of enamel caries was markedly reduced in the fluoridated area. No pre-eruptive effect could be observed if the total number of lesions, including enamel lesions, from Tiel and Culemborg were compared.     

Dental health in schoolchildren 5 years after water fluoridation ceased in south-west Scotland

A follow-up study of the dental health of children resident in two towns in south-west Scotland, one of which had fluoridated water until 1983, was carried out at the end of 1988. Comparison with an identical 1980 study allowed trends in the prevalence of caries to be examined. In 1988, the mean, decayed, missing and filled deciduous teeth (dmft) score for 5-year-old children in Stranraer, the formerly fluoridated town, was 3.08, 24 per cent worse than the score of 2.48 reported in 1980. In Annan, mean dmft for 5-year-old children was 3.18 in 1988, 27 per cent lower than the 1980 dmft score of 4.38. The difference in caries prevalence between the two towns in 1988 was a non-significant 3.1 per cent compared with the 44 per cent difference found in 1980. Similar trends in caries prevalence were also found in 10-year-old children with mean DMFT scores of 2.28 in Stranraer and 2.56 in Annan in 1988, a 10.9 per cent difference compared with the 50 per cent difference reported in 1980. The Stranraer DMFT score was 37.4 per cent higher than the DMFT of 1.66 recorded in 1980, while in Annan, the mean DMFT of 2.56 was 23.6 per cent lower than the 1980 score of 3.35. The comparison confirms a trend to lower caries levels in Annan children in line with the general trend in caries prevalence in much of western Europe. However, despite the almost universal use of fluoride toothpaste, caries prevalence in Stranraer children has increased since fluoridation ceased to almost parity with children in the non-fluoridated area. This study shows that there is still a benefit to be gained in terms of lower caries rates by implementing water fluoridation despite the general decline in dental caries.     

Enamel defects and dental caries in 9-year-old children living in fluoridated and nonfluoridated areas of Auckland, New Zealand

Abstract – Objectives: This epidemiological study aims to investigate the developmental enamel defects and dental caries among 9‐year‐old children resident in fluoridated and nonfluoridated regions in Auckland, New Zealand. Methods: A stratified, two‐stage random selection design where strata were defined by fluoridation status, school size, and school decile. After informed consent was obtained, parents completed oral health questionnaires and children underwent dental examinations at school clinics. Results: 612 children from 38 schools participated in the study. Overall, 175 (29%) children had lived continuously in fluoridated areas, 149 (24%) had lived continuously in nonfluoridated areas, and 288 (47%) had resided intermittently in fluoridated areas. Diffuse opacities were present in 117 (19%) children and deciduous teeth dental caries was seen in 370 (60%) children. After adjustment for covariates, a strong dose–response relationship between diffuse opacity and fluoridation status was found, with children who lived continuously in fluoridated areas being 4.17 times as likely to have diffuse opacities as children who lived continuously in nonfluoridated areas (P < 0.001). Conversely, a strong protective dose–response relationship between caries experience and fluoridation status was seen, with children who lived continuously in fluoridated areas being 0.42 times as likely to have dental caries as children who lived continuously in nonfluoridated areas (P < 0.001). Conclusions: Reticulated water fluoridation in Auckland reduces the risk of dental caries but increases the risk of diffuse opacities in 9‐year‐old children. Guidelines and health‐promotion strategies that enable children to minimize their risk to diffuse opacities yet reduce their risk of dental caries should be reviewed.     

Prevalence of caries and developmental defects of enamel in 9-10 year old children living in areas in Brazil with differing water fluoride histories

AIMS: To assess the prevalences of caries, of developmental defects of enamel and their interrelationship in Brazilian 9-10-year-olds from areas of contrasting fluoridation histories. METHODS: Systematic random sampling procedures were used to select children from an area where water had been fluoridated in 1963 and from a second area where water had been fluoridated since 1998. Clinical examinations for caries were carried out using the DMFT index and WHO diagnostic criteria. Developmental defects of enamel on upper incisors were diagnosed using the DDE index. RESULTS: A difference of 40% in DMFT was observed, with a lower prevalence of disease in the area fluoridated since 1963. Diffuse opacities affected 14.3% of the children from the area fluoridated since 1963 compared with only 2.4% in the area fluoridated in 1998. Children living in the area fluoridated in 1963 who had diffuse defects had twice the chance of being free from caries compared with those living in the same area who had no defects or who had only demarcated or hypoplastic defects. CONCLUSIONS: This study confirms previous ones in showing the benefits of water fluoridation. Diffuse opacities of upper incisors affected relatively few subjects in either of the two areas.     

Incisor caries in Western Australian children

In a comparison of caries of the incisor teeth of ten year old children living in a fluoridated area and those living in a non-fluoridated area, the prevalence of proximal lesions was found to be low (three teeth per 100 children) in the fluoridated area.     

The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers,environmental registers and administrative registers

Kirkeskov L, Kristiansen E, Bøggild H, von Platen‐Hallermund F, Sckerl H, Carlsen A, Larsen MJ, Poulsen S. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Community Dent Oral Epidemiol 2010; 38: 206–212. © 2010 John Wiley & Sons A/S Abstract – Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children. Methods: The study linked registry data on fluoride concentration in drinking water over a 10‐year period with data on dental caries from the Danish National Board of Health database on child dental health for 5‐year‐old children born in 1989 and 1999, and for 15‐year‐old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used to assess the correlations, adjusting for gender and taxable family income as a proxy variable for socioeconomic status. Results: Fluoride concentration in drinking water varied considerably within the country from very low (<0.10 mg/l) to more than 1.5 mg/l. Only little variation was found over the 10‐year study period. Dental caries in both 5‐year‐olds and 15‐year‐olds decreased over the study period. An inverse relation between the risk of dental caries and fluoride concentration in drinking water was found in both primary and permanent teeth. The risk was reduced by approximately 20% already at the lowest level of fluoride exposure (0.125–0.25 mg/l). At the highest level of fluoride exposure (>1 mg/l), a reduction of approximately 50% was found. Similar findings were found if analysis was limited to children residing in the same place during the entire study period. Conclusions: The study confirmed previous findings of an inverse relation between fluoride concentration in the drinking water and dental caries in children. This correlation was found in spite of the extensive use of fluoridated toothpaste and caries‐preventive programs implemented by the municipal dental services in Denmark. Linking Danish health registers with environmental and administrative registers offers an opportunity for obtaining sample sizes large enough to identify health effect, which otherwise could not be identified.     

Dental caries among 12-year-old children in northern Poland between 1987 and 2003.

AIM: In 1987, 1995 and 2003 dental surveys were carried out in the Gdansk region of Poland investigating the prevalence of dental caries in 12-year-old school children. MATERIALS AND METHODS: Sampling and examination were performed according to WHO standards. A sample of 180 children in each year were selected from different living environments: a large city, a small town and a rural area. RESULTS: The caries prevalence (ratio of caries-free children) and caries experience (mean DMFT scores) changed significantly in some groups in the period from 1987-2003. However, there was no change in caries experience in children living in a large city. The average DMFT score of all 12-year-olds dropped from 4.07 in 1987 to 3.20 in 2003. CONCLUSION: The remarkable improvement of dental health may be explained by the oral health education and increased availability of fluoridated toothpaste.     

Dental caries experience in Australian Army recruits 2002-2003

BACKGROUND: Recent data have suggested that the trend of decreasing caries experience in Australian children is slowing with increasing dmft and DMFT scores seen in children. However, there are limited data on dental caries experience in young Australian adults. METHODS: A cross-sectional study of 973 Australian Army recruits was conducted between November 2002 and March 2003. A clinical examination with bitewing radiographs was conducted and a questionnaire was used to elicit socio-demographic information. RESULTS: Mean DMFT scores were 2.43, 3.44, 5.48, 7.02 and 10.77 for subjects aged 17-20, 21-25, 26-30, 31-35 and 36-51 years respectively. Subjects with a lifetime exposure to fluoridated drinking water had a mean DMFT of 2.80 while subjects with no exposure to fluoridated drinking water had a mean DMFT of 3.91. Multivariate Poisson regression found that age, level of educationand lifetime exposure to fluoridated drinking water had a statistically significant effect on caries experience. CONCLUSIONS: It appears that there has been a continual decline in caries experience and prevalence in young Australian adults between 1996 and 2002-2003. Lifetime exposure to fluoridated drinking water conferred an appreciable benefit for subjects in this study compared with subjects with no exposure to fluoridated drinking water.     

Risk-benefit balance in the use of fluoride among young children

This study aimed to evaluate the risk-benefit balance of several fluoride exposures. Fluoride exposure history of randomly selected children was collected for calculation of exposure to fluoridated water, toothpaste, and other fluoride sources. We evaluated the risk-benefit balance of fluoride exposure by comparing dental fluorosis on maxillary central incisors, recorded at the time of the study with the use of the Thylstrup and Fejerskov Index, and deciduous caries experience, recorded at age six years, of the same group of South Australian children who were from 8 to 13 years old in 2002-03. Population Attributable Risk for fluorosis and Population Prevented Fraction for caries were estimated. Fluorosis prevalence was found to be 11.3%; caries prevalence, 32.3%; mean dmfs, 1.57 (SD 3.3). Exposure to fluoridated water was positively associated with fluorosis, but was negatively associated with caries. Using 1000-ppm-F toothpaste (compared with 400- to 550-ppm-F toothpaste) and eating/licking toothpaste were associated with higher risk of fluorosis without additional benefit in caries protection. Evaluation of the risk-benefit balance of fluoride exposure provides evidence to assist in the formulation of appropriate guidelines for fluoride use.     

Dental caries experience in young Australian Army recruits 2008

Background: Recent studies have shown a substantial decline in caries experience in Australian Army recruits between 1996 and 2002–2003, and in Australian adults between 1987–1988 and 2004–2006. However, studies in children have reported an increasing trend in caries experience between 1998 and 2002. The aim of this study was to investigate caries experience in Australian Army recruits in 2008. Methods: A cross‐sectional study involving 1084 Australian Army recruits was conducted from January to May 2008. Data were obtained from a clinical dental examination with bitewing radiographs, and a questionnaire elicited socio‐demographic data and history on lifetime exposure to fluoridated drinking water. Results: Mean DMFT scores were 3.16, 4.08, 5.16 and 7.11 for recruits aged 17–20, 21–25, 26–30 and 31–35 years, respectively. Recruits with a lifetime exposure to fluoridated drinking water had a mean DMFT of 3.02, while recruits with no exposure had a mean DMFT of 3.87. Conclusions: Caries experience in Australian Army recruits aged 17–25 years increased between 2002–2003 and 2008. Recruits with lifetime exposure to fluoridated drinking water had 25 per cent less caries experience compared with recruits who had no exposure to fluoridated drinking water after adjusting for the effects of age, gender, education and socio‐economic status.     

Dental caries and enamel fluorosis among the fluoridated and non-fluoridated populations in the Republic of Ireland in 2002

BACKGROUND: A national survey of oral health of children and adolescents was carried out in the Republic of Ireland (RoI) in 2001/2002. AIMS: To compare the prevalence of caries between child and adolescent residents in fluoridated and non-fluoridated communities in the RoI whilst controlling for disadvantage. To compare caries levels amongst disadvantaged and non-disadvantaged groups with and without water fluoridation. To report the changes in caries levels between the 1960s and 2002 in RoI. To report the changes in dental fluorosis levels between 1984 and 2002. METHODOLOGY: Cross sectional oral health survey of a representative, random, stratified sample of 17,851 5-, 8-, 12- and 15-year-old children and adolescents in RoI. WHO examination criteria with the addition of visible, non-cavitated dentine caries were used for recording caries. Fluorosis was measured using Dean's Index. RESULTS: In the RoI the mean dmft/DMFT scores for 5-, 8-, 12-, and 15-year-olds were 1.2, 0.3, 1.1 and 2.3. For those with domestic water fluoridation since birth the scores were 1.0, 0.3, 1.1 and 2.1 respectively. In non-fluoridated areas of RoI the mean dmft/DMFT scores for 5-, 8-, 12-, and 15-year-olds was 1.7, 0.3, 1.3 and 3.2, respectively. For 5-, 12- and 15-year-old age groups dental caries levels were lower amongst children with fluoridated domestic water supplies (all p<0.0001). The prevalence of dental fluorosis has increased in RoI since 1984. 23% and 36% of 8- and 15-year olds respectively in fluoridated areas had Dean's Index scores at the questionable or greater level in 2002, compared with 6% and 5% respectively in 1984. CONCLUSIONS: Caries levels are lower among children with fluoridated domestic water supplies. Decay levels are much lower in 2002 than they were in 1984 and in the 1960s. The oral health of the less well off is worse than that of the rest of the population. The prevalence of dental fluorosis is higher amongst children and adolescents with fluoridated water supplies. Comparisons with 1984 data show an increase in the prevalence of fluorosis since that time.     

Enhanced anticaries action from drinking water containing 5 ppm fluoride.

Dental examinations were conducted on 1,878 adolescent schoolchildren native to seven US cities in five states, where the water was fluoride-deficient, fluoridated, or contained approximately 5 ppm of naturally occurring fluoride. Dental caries experience was considerably lower in all the communities with fluoridated water than in Boston, which had water deficient in fluoride, and ranged from 38% to 83% fewer mean DMF for the children in the regions with fluoridated water than for the children in Boston. Moreover, dental caries experience was significantly lower in Midland, Tex (5 to 7 ppm fluoride) than in each of the four cities with fluoridated water, and approximately 50% of the children in Midland had no caries. This report provides strong evidence that a much greater protection against human dental caries can result from a higher concentration of fluoride than is customarily recommended as best for prevention of caries. Fluoridating community waters to concentrations higher than 1 to 2 ppm fluoride, however, is not suggested because of the high risk of producing unesthetic enamel fluorosis.     

Caries prevalence in 6-, 11- and 14-year-old children in the Cyclades Islands, Greece

Following the World Health Organization criteria, a total of 1,604 out of 3,225 children aged 6, 11 and 14 years living on the 20 islands of the Cyclades complex were examined. Recordings showed that in the 6-year-old children, the mean dmft index was 2.21 (SD=3.00) with 46% caries free. In the 11-year-old children, the DMFT averaged 1.39 (SD=1.78) with 46% caries free. In the 14-year-old children, the mean DMFT was 2.62 (SD=2.83) with 32% caries free. Statistically significant differences were found in the DMFT of the 11- and 14-year-old subjects living in naturally water fluoridated and non-fluoridated areas. According to these data, it appears that the first two WHO targets for the year 2000 are almost fulfilled.     

Community fluoridation status and caries experience in children

OBJECTIVE: This study compares dental caries experience in fluoridated and nonfluoridated communities. METHODS: A dental health survey designed to collect data on caries experience and treatment needs for community-specific public health planning purposes was conducted in public elementary schools during the 1996-97 school year. Oral examinations of 17,256 children were completed, representing 93 percent of children residing in 62 East Tennessee communities. RESULTS: The analysis showed that water fluoridation was significantly related to caries experience in the primary (dfs) and permanent (DMFS) dentitions and to the proportion of caries-free children in the primary and permanent dentitions. When the data were adjusted for socioeconomic status, race, and age, caries levels were 21 percent lower in the primary dentition and 25 percent lower in the permanent dentition in fluoridated communities than in nonfluoridated communities. In addition, the proportion of children who were caries free was larger in fluoridated as compared with nonfluoridated communities by 19 percent in the primary dentition and 6 percent in the permanent dentition. CONCLUSION: Although the design of the study prevented the collection of individual fluoride and residency histories, findings suggest there was substantially lower caries experience in fluoridated communities than in nonfluoridated communities.     

Association between infant formula feeding and dental fluorosis and caries in Australian children

Objective: The objective of this study was to evaluate associations between patterns of infant formula feeding and dental fluorosis and caries in a representative sample of Australian children. Methods: A population‐based study gathered information on fluoride exposure in early childhood. Information on infant formula feeding and fluoridation status was used to group children: three groups in nonfluoridated areas (formula nonuser, user for ≤6 months, and user for 6+ months) and four groups in fluoridated areas (nonuser, user with nonfluoridated water, user with fluoridated water for ≤6 months, and user with fluoridated water for 6+ months). Children aged 8‐13 years were examined for fluorosis using the Thylstrup and Fejerskov (TF) Index. Primary tooth caries experience recorded at age 8‐9 years was extracted from clinical records. Fluorosis cases were defined as having TF 1+ on maxillary incisors. Fluorosis prevalence and primary caries experience were compared across formula user groups in multivariable regression models adjusting for other factors. Results: Total sample was 588 children. Children in fluoridated areas had higher prevalence of very mild to mild fluorosis, but lower caries experience than those in nonfluoridated areas. Among children in nonfluoridated areas, formula users for 6+ months had significantly higher prevalence of fluorosis compared with nonusers. There was no significant difference in fluorosis prevalence among the formula users in fluoridated areas. Among children in fluoridated areas, formula users with nontap water had higher caries experience. Conclusion: Infant formula use was associated with higher prevalence of fluorosis in nonfluoridated areas but not in fluoridated areas. Type of water used for reconstituting infant formula in fluoridated areas was associated with caries experience.     

A comparison of dental caries levels in two communities with different oral health prevention strategies stratified in different social classes

OBJECTIVES: To compare dental caries levels of schoolchildren stratified in different social classes whose domestic water supply had been fluoridated since birth (Dublin) with those living in an area where fluoridated salt was available (Freiburg). METHODS: A representative, random sample of twelve-year-old children was examined and dental caries was recorded using World Health Organization criteria. RESULTS: A total of 699 twelve-year-old children were examined, 377 were children in Dublin and 322 in Freiburg. In Dublin the mean decayed, missing, and filled permanent teeth (DMFT) was 0.80 and in Freiburg it was 0.69. An examination of the distribution of the DMFT score revealed that its distribution is highly positively skewed. For this reason this study provides summary analyses based on medians and inter-quartile range and nonparametric rank sum tests. In both cities caries levels of children in social class 1 (highest) were considerably lower when compared with the other social classes regardless of the fluoride intervention model used. The caries levels showed a reduced disparity between children in social class 2 (medium) and 3 (lowest) in Dublin compared with those in social class 2 and 3 in Freiburg. CONCLUSIONS: The evidence from this study confirmed that water fluoridation has reduced the gap in dental caries experience between medium and lower social classes in Dublin compared with the greater difference in caries experience between the equivalent social classes in Freiburg. The results from this study established the important role of salt fluoridation where water fluoridation is not feasible.     

Effectiveness of acidified fluoride solutions in prevention of dental caries in school children

The purpose of the study was assessment of the influence of locally applied acidified fluoride solutions on the condition of teeth of school children living in a town district with fluoridated drinking water and in another district without fluoridation of drinking water. Acidified fluoride solutions were applied locally by brushing--5 procedures at two-week intervals in the first and second year of the experiment. The condition of teeth was assessed calculating the indices CMF and CMFp. In the light of the obtained results it may be said that the externally applied acidified solutions of fluorides had an approximately evident effectiveness in prevention of caries both in children drinking fluoridated or non-fluoridated water.     

Exposure to water fluoridation and caries increment

OBJECTIVE: The objective of this cohort study was to examine the association between exposure to water fluoridation and the increment of dental caries in two Australian states: Queensland (Qld)--5 per cent fluoridation coverage; and South Australia (SA)--70 per cent fluoridation coverage. METHOD: Stratified random samples were drawn from fluoridated Adelaide and the largely non-fluoridated rest-of-state in SA, and fluoridated Townsville and non-fluoridated Brisbane in Qld. PARTICIPANTS: Children were enrolled between 1991 and 1992 (SA: 5-15 yrs old, n = 9,980; Qld: 5-12 yrs old, n = 10,695). Follow-up caries status data for 3 years (+/- 1/2 year) were available on 8,183 children in SA and 6,711 children in Qld. MAIN OUTCOME MEASURES: Baseline data on lifetime exposure to fluoridated water, use of other fluorides and socio-economic status (SES) were collected by questionnaire, and tooth surface caries status by dental examinations in school dental service clinics. RESULTS: Higher per cent lifetime exposure to fluoridated water (6 categories: 0;1-24; 25-49; 50-74; 75-99; 100 per cent) was a significant predictor (ANOVA, p < 0.01) of lower annualised Net Caries Increment (NCI) for the deciduous dentition in SA and Qld, but only for Qld in the permanent dentition. These associations persisted in multiple linear regression analyses controlling for age, gender, exposure to other fluorides and SES (p < 0.05). CONCLUSIONS: Water fluoridation was effective in reducing caries increment, even in the presence of a dilution effect from other fluorides. The effect of fluoridated water consumption was strongest in the deciduous dentition and where diffusion of food and beverages from fluoridated to non-fluoridated areas was less likely.     

Dental caries and enamel fluorosis among the fluoridated population in the Republic of Ireland and non fluoridated population in Northern Ireland in 2002

BACKGROUND: An all Ireland/North South survey of Oral Health was carried out in 2001/2002. AIMS: To compare levels of dental caries and enamel fluorosis among children and adolescents in the fluoridated Republic of Ireland (RoI) with those in the non fluoridated North of Ireland (NI). METHODOLOGY: Cross sectional oral health survey of a representative, random, stratified sample of 5-, 8-, 12- and 15-year-olds in Rol and in NI (N = 19,950). WHO examination criteria with the addition of visible, non cavitated dentine caries were used for recording caries. Fluorosis was measured using Dean's Index. RESULTS: In the RoI, the mean d(3c)mft / D(3c)MFT for 5-, 8-, 12-, and 15-year-olds with full domestic water fluoridation (n = 9,975), was 1.0, 0.3, 1.1 and 2.1 respectively. The corresponding means in non fluoridated NI (n = 1,475) were 1.8, 0.3, 1.5 and 3.6 respectively. (p < 0.0001, NS, p < 0.0005 and p < 0.0001). The prevalence of enamel fluorosis has increased in RoI since 1984, 23% and 36% of 8- and 15-year olds respectively in fluoridated areas had Dean's Index scores at the questionable or greater level in 2002 compared with 6% and 5% respectively in 1984. CONCLUSIONS: In 2002 apart from 8-year-olds, caries levels were lower amongst children resident in fluoridated communities in RoI than amongst corresponding age groups in non-fluoridated NI. Caries has declined in fluoridated and non fluoridated groups in both jurisdictions since the early 1960s. In RoI fluorosis levels were higher amongst lifetime residents of fluoridated communities and have increased since 1984.     

Dental caries experience of 16–17-year-old naval recruits related to the water fluoride level in their home town

Abstract Out of 6694 recruits who joined the Royal Navy between September 1979 and February 1981. 1983 (30%) had lived all their lives in one locality. Information on the fluoride level, between 1963 and 1980, in the water supply to each of the recruits' homes was obtained. The examiner recording the dental status of each recruit did not know where the recruit had lived. Some of the information on fluoride levels was imprecise or of variable quality so the final analyses were restricted to 1332 16–17-year-old subjects. The overall mean DMFT for the 1332 recruits was 9.72. There was a consistent fall in caries experience with increasing water fluoride level although the difference between the caries experience of recruits from low and high fluoride areas (about 20% for mean DMFT) was smaller than that observed in other studies. A possible explanation for this smaller difference is that some of the subjects did not receive fluoridated water early in life.