Dental caries and fluoride exposure in Western Australia

Water fluoridation in Australia: A systematic review

Water fluoridation is considered a safe and effective public health strategy to improve oral health. This review aimed to systematically summarize the available evidence of water fluoridation in Australia, focusing on the history, health impacts, cost effectiveness, challenges, and limitations. A systematic search was conducted on the Ovid Medline, Web of Science, Scopus, ProQuest Central, Cinahl, and Informit databases to identify literature on water fluoridation in Australia. A grey literature search and backward snowballing were used to capture additional literature. Primary studies, reviews, letters, and opinion papers were included in the quantitative analysis and summarized based on the year of publication and geographical location. The data were extracted from primary studies and summarized under three subheadings: history, community health impacts and the limitations and challenges. Water fluoridation in Australia was first implemented in 1953 in Tasmania. Most states and territories in Australia embraced water fluoridation by 1977 and currently, 89% of the Australian population has access to fluoridated drinking water. Studies report that water fluoridation has reduced dental caries by 26-44% in children, teenagers, and adults, benefiting everyone regardless of age, income, or access to dental care. It has been recognized as a cost-effective intervention to prevent dental caries, especially in rural and low-income areas. Water fluoridation as a public health measure has faced challenges, including political and public opposition, implementation and maintenance costs, access and equity, communication and education, and ethical concerns. Variations in research activities on water fluoridation across Australian states and territories over the last seven decades can be due to several factors, including the time of implementation, funding, and support. Ongoing monitoring and research to review and update optimal fluoride levels in drinking water in Australia is warranted to ensure sustainable benefits on oral health while preventing any adverse impacts.

Fluoride content of tank water in Australia

BACKGROUND

The aims of this study were to: (1) analyse the fluoride content of tank water; (2) determine whether the method of water collection or storage influenced fluoride content; and (3) survey participant attitudes towards water fluoridation.

METHODS

Plastic tubes and a questionnaire were distributed through dentists to households with water tanks in Victoria. A midstream tank water sample was collected and fluoride analysed in triplicate using ion chromatography

RESULTS

All samples (n = 123) contained negligible amounts of fluoride, with a mean fluoride concentration of <0.01 ppm (range: <0.01-0.18 ppm). No statistically significant association was found between fluoride content and variables investigated such as tank material, tank age, roof material and gutter material. Most people did not know whether their tank water contained fluoride and 40.8% preferred to have access to fluoridated water. The majority thought fluoride was safe and more than half of the respondents supported fluoridation. Fluoride content of tank water was well below the optimal levels for caries prevention.

CONCLUSIONS

People who rely solely on tank water for drinking may require additional exposure to fluoride for optimal caries prevention.

Patterns of attendance of children under 12 years at school dental service in Western australia

The aim of this study was to investigate the patterns of attendance at School Dental Service (SDS) and reasons for attendance (treatment or prevention) for children in the Perth Metropolitan Area, in particular investigating the first year of SDS attendance and attendance until the year the child turned 12. The first 150 SDS records located for children from the Western Australian Pregnancy Cohort (Raine) Study were used for this study. Patterns of attendance of children at SDS were described, as were associated factors (enrolment, age and nature of first visit, general nature of visits and number of visits) until the end of the year that the child turned 12.

The age of the child at the first SDS visit ranged from 4 years 3 months to 14 years 11 months, with a median of 5 years 1 month. First visits were primarily for an examination (98%). Children had a median of 13 visits until 12 years of age, with 10% having less than five visits and 4% having more than 25 visits.

These data provide useful information regarding attendance at the SDS in Western Australia which could provide a basis for oral health promotion programs.

A saúde bucal de adolescentes: aspectos de higiene, de cárie dentária e doença periodontal nas cidades de Recife, Pernambuco e Feira de Santana, Bahia

OBJETIVO: Caracterizar a saúde bucal de adolescentes nas cidades de Recife e Feira de Santana, pela avaliação de higiene bucal, cárie dentária e doença periodontal. MÉTODO: Foram avaliados 40 adolescentes com 10 a 18 anos de idade em Recife, em estudo exploratório, em 2005 e, em Feira de Santana, 971 adolescentes com 12 anos idade, num estudo de prevalência, em 2002. Avaliaram-se: cárie, pelo número de dentes cariados, perdidos e obturados; placa dentária visível, sangramento gengival e condição periodontal. Para análise, utilizaram-se os testes Quiquadrado, Kruskall-Wallis, Exato de Fisher, com intervalo de confiança de 95%. RESULTADOS: A maioria dos adolescentes realizavam higiene oral três vezes ao dia. Os valores do CPOD apresentaram mediana de 1,5 em Recife e médias de 1,89 nas escolas estaduais, 2,17 nas municipais e 2,39 nas particulares, em Feira de Santana. O sangramento gengival em Recife teve mediana de 27% e, em Feira de Santana, a média de sextantes sadios foi de 4,36, 4,08 e 5,16, nas escolas estaduais, municipais e particulares respectivamente. CONCLUSÃO: A freqüência da cárie dentária foi baixa, a maioria dos adolescentes relatou bons hábitos de higiene bucal e a condição periodontal nos adolescentes foi favorável.

Consumption of nonpublic water: implications for children's caries experience

There are concerns that the consumption of unfluoridated bottled and tank water may put children at increased risk of developing caries.

OBJECTIVES

The aim of this study was to investigate the relationship between nonpublic water consumption (either from bottles or rainwater tanks) and socioeconomic status (SES) and both deciduous and permanent caries experience.

METHODS

A random sample of children enrolled in the School Dental Service of South Australia participated in the study (response rate = 71.8%, n = 9988).

RESULTS

Forty-five per cent of children had greater than 50% lifetime consumption of nonpublic water while 36% of children had 0% lifetime consumption. Increased use of nonpublic water occurred for children from lower socioeconomic groups, two-parent families and children from nonmetropolitan areas, with these results most likely a result of the residential location of the children. Multivariate modelling revealed a significant positive relationship between deciduous caries experience and consumption of nonpublic water, even after controlling for the age and sex of the child, SES and residential location. This relationship was significant only for those children with 100% lifetime availability of fluoridated water. The effect of consumption of nonpublic water on permanent caries experience was not significant. It is postulated that these findings may result from the lower caries activity in the permanent dentition of children aged 10-15 and possible dietary confounders.

CONCLUSION

Recommendations are made for the addition of fluoride to bottled water, especially with regard to the oral health of younger children.

Exposure to fluoridated drinking water and dental caries experience in Australian army recruits, 1996

OBJECTIVES

The purpose of this study was to investigate a group of young Australian adults to determine their caries experience and measure associations between caries experience and age, gender, socioeconomic status, education level and lifetime exposure to fluoridated water.

METHODS

This was achieved through a cross-sectional study involving Australian Army recruits seen for their initial dental examination on enlistment into the Australian Army. A total of 499 recruits had a clinical examination with the aid of bitewing radiographs and an orthopantomograph (OPG). Sociodemographic and fluoride exposure data were obtained via a questionnaire.

RESULTS

This study showed that subjects with a lifetime exposure to fluoridated water reported a 23% lower level of caries experience than subjects with no exposure to fluoridated water, with a greater effect on proximal surfaces compared to smooth and occlusal surfaces. Female subjects had a level of caries experience 25% higher than male subjects, while subjects from the lowest socioeconomic background had a level of caries experience 89% times greater than subjects from the highest socioeconomic group.

CONCLUSIONS

Although it is not possible to directly establish a causal relationship from a cross-sectional study such as this, the results from this study show a dose-response relationship which suggests that there are benefits of lifetime exposure to fluoridated drinking water through young adulthood.

Dental fluorosis decline after changes to supplement and toothpaste regimens

In 1989/90, in 659 12-year-olds in Perth (F 0.8 mg/L) and the Bunbury region of Western Australia (WA) (F approximately 0.25 mg/L), dental fluorosis prevalences were 40.2% and 33.0%. Fluoride supplements (OR 4.63) and extended residence in a fluoridated area (OR 4.06) were significant risk factors; toothpaste ingestion variables had ORs greater than unity; in 1990, DMFT for this age group was 0.84. School Dental Service took steps to discourage supplement and toothpaste ingestion and to promote low fluoride toothpaste for children < 6 years of age.

OBJECTIVES

To evaluate the effect of this campaign on fluorosis and caries.

METHODS

Between May-July 2000, 582 10-year-olds were examined for dental fluorosis (TF index) and dental caries (DMFT) in school dental clinics.

RESULTS

Fluorosis prevalence was 22.2% in Perth and 10.8% in the Bunbury region. Overall prevalence was 18.0% and of this, 80.2% was TF 1, 17.9% was TF 2 and just 1.9% was TF 3. In 1989/90, 79 children had used supplements before the age of 4 year; in 2000 only 40 had done so (P < 0.001). Mean DMFT values in Perth and Bunbury were 0.32 and 0.28 (P > 0.05). Low F toothpaste, unavailable in 1989/90, had been used by 24.5%. The only significant risk factor was residence, OR 2.0.

CONCLUSIONS

Fluorosis prevalence seems to have fallen in parallel with a reduction in discretionary intake from supplements and toothpaste. No increase in dental caries experience was recorded. Because the teeth examined in this study were at risk of fluorosis in 1992-95, very soon after policies changed, and because people are slow to change health habits, it seems reasonable to expect a further improvement when teeth mineralised in the late 1990s become visible.

US drinking water: fluoridation knowledge level of water plant operators

OBJECTIVES

We determined the knowledge level of water plant operators who fluoridate drinking water, and we compared small and large water plants.

METHODS

A pretested survey was sent to 2,381 water plant operators in 12 states that adjust the fluoride concentration of drinking water. A z-test for proportion was used to test for statistical difference between small and large plants at alpha = 0.05. Small water plants were those treating less than 1 million gallons of water daily.

RESULTS

Eight hundred small and 480 large water plant operators responded, resulting in a response rate of 54 percent. Two-thirds of water plant operators correctly identified the optimal fluoride level, but more than 20 percent used a poor source for choosing the optimal level. Only one-fourth of operators were able to maintain the fluoride concentration to within 0.1 mg/L of the optimal concentration. A significantly greater proportion of operators at large water plants than at small water plants reported that they were able to maintain a fluoride concentration to within 0.1 mg/L of the optimal concentration (33.5% vs 21.3%, z = 4.74, P < .05).

CONCLUSIONS

Although most operators correctly identified the optimal fluoride level, small water plant operators were less likely to use accurate reasoning for choosing that level and in maintaining fluoride concentrations within 0.1 mg/L of that level than large water plant operators.

The prevalence of dental caries and fluorosis in Japanese communities with up to 1.4 ppm of naturally occurring fluoride

OBJECTIVES

The purpose of this study was to determine the relationship between the concentration of fluoride in drinking water and the prevalence of dental caries and fluorosis in seven Japanese communities with different concentrations of fluoride occurring naturally in the drinking water.

METHODS

A total of 1,060 10- to 12-year-old lifetime residents were examined to determine the prevalence of dental caries and fluorosis in communities with trace amounts to 1.4 ppm fluoride in the drinking water in 1987. Systemic fluorides (drops or tablets) have never been available in Japan and the market share of fluoride-containing toothpaste was 12 percent at the time of the study.

RESULTS

The prevalence of dental caries was inversely related and the prevalence of fluorosis was directly related to the concentration of fluoride in the drinking water. The mean DMFS in the communities with 0.8 to 1.4 ppm fluoride was 53.9 percent to 62.4 percent lower than that in communities with negligible amounts of fluoride. Multivariate analysis showed that water fluoride level was the strongest factor influencing DMFS scores. The prevalence of fluorosis ranged from 1.7 percent to 15.4 percent, and the increase in fluorosis with increasing fluoride exposure was limited entirely to the milder forms.

CONCLUSIONS

The findings of this study conducted in 1987 in Japan parallel those reported by Dean et al. in the early 1940s.

Analysis of fluoride levels retained intraorally or ingested following routine clinical applications of topical fluoride products

A variety of topical fluorides is now used clinically for the prevention and control of dental caries. It is essential for the dental profession to be fully aware of the relative retention rates of fluoride in saliva and thus its contact with the teeth. These may vary following the use of the different categories and concentrations of agents available and with different methods of use. It is also important to be aware of the amounts of fluoride ion ingested following use of the more concentrated forms and of the resultant elevation in total blood fluoride levels. These parameters were investigated in a series of experiments involving human volunteer subjects using a variety of topical fluoride materials commercially available in Australia. Fluoride mouthrinses appeared to provide the highest salivary retention rates per dose of all forms of topical fluoride. Ingestion rates from concentrated gels were acceptable when effective evacuation methods were applied. The use of custom-made trays resulted in a reduction in amounts of fluoride ion ingested, though simple self-application by toothbrush of smaller quantities proved to be an effective alternative in terms of amount of fluoride ion retained in saliva per amount applied and ingested. None of the concentrated gels used resulted in elevations in total blood fluoride levels which were of concern in adults. It is acknowledged that salivary retention rates of fluoride ion do not necessarily reflect the caries inhibitory effects of topical fluorides. However, these data provide some indication of possible advantages of some products and methods of application over others.

The reliability of interview data for age at which infants' toothcleaning begins

A number of studies have reported on the age at which toothbrushing started and drawn important conclusions. Such studies often relied on parental recall of a particular event that occurred some years previously, assuming the quality of retrospectively reported data. The present study aimed to investigate consistency of reporting the age at which toothcleaning began. Mothers from two different cultural backgrounds, 100 Caucasian and 150 Asian living in a deprived inner city area, were interviewed in their homes on two separate occasions, when the sample child was 6-24 months old and again at 3-4 years. Of the 39 Caucasian and 31 Asian mothers who specified an age at which toothbrushing commenced at both interviews, complete agreement occurred among 4 (10%) Caucasian and 2 (6%) Asian mothers, with a variation of +/- 2 months among 12 (31%) and 5 (16%) respectively. Intraclass correlation coefficients were -0.01 for Caucasian and -0.46 for Asian mothers. Kappa values were 0 and -0.09 respectively. Of the 139 mothers who stated that their children's teeth were not cleaned at the time of the first interview, 17 claimed an earlier age than this at the second interview. It was concluded that there was little agreement between the two interviews, although the extent of the variation differed between the two cultural groups. Although these findings represent relatively deprived population groups, caution is recommended in unquestioningly accepting the accuracy of retrospective reporting of oral hygiene practices in dental surveys until evidence of better reliability is available.

New, or biased, evidence on water fluoridation?

The recent review, 'New evidence on fluoridation', by Diesendorf, Colquhoun, Spittle, Everingham and Clutterbuck (Aust N Z J Public Health 1997; 21: 187-90) claims a consistent pattern of evidence pointing to fluoride damaging bone, a negligible benefit in dental caries reduction from ingested fluoride, and any small benefit from fluoride coming from the action of fluoride at the tooth surface. Public health authorities are allegedly reluctant to pursue such evidence. In the interest of scholarly debate, invited by Diesendorf et al., this reaction paper examines six separate areas raised in the original paper: fluoridation and hip fracture; fluoridation and osteosarcomas; pre-eruptive and posteruptive benefits in dental caries reduction; fluoride ingestion; benefit in dental caries reduction for contemporary Australian children; and bias of health authorities and responsible science. Numerous examples of bias in the identification, selection and appraisal of the evidence on water fluoridation presented by Diesendorf et al. are developed. Further, this reaction paper puts forward both studies and appraisal indicating that water fluoridation should continue to be regarded as a safe and effective public health measure.

Dental caries and dental fluorosis at varying water fluoride concentrations

OBJECTIVES

The purpose of this study was to investigate the relationships between caries experience and dental fluorosis at different fluoride concentrations in drinking water. The impact of other fluoride products also was assessed.

METHODS

This study used data from the 1986-87 National Survey of US School-children. Fluoride levels of school water were used as an indicator of the children's water fluoride exposure. The use of fluoride drops, tablets, professional fluoride treatments, and school fluoride rinses were ascertained from caregiver questionnaires. Only children with a single continuous residence (n = 18,755) were included in this analysis.

RESULTS

The sharpest declines in dfs and DMFS were associated with increases in water fluoride levels between 0 and 0.7 ppm F, with little additional decline between 0.7 and 1.2 ppm F. Fluorosis prevalence was 13.5 percent, 21.7 percent, 29.9 percent, and 41.4 percent for children who consumed < 0.3, 0.3 to < 0.7, 0.7 to 1.2, and > 1.2 ppm F water. In addition to fluoridated water, the use of fluoride supplements was associated with both lower caries and increased fluorosis.

CONCLUSIONS

A suitable trade-off between caries and fluorosis appears to occur around 0.7 ppm F. Data from this study suggest that a reconsideration of the policies concerning the most appropriate concentrations for water fluoridation might be appropriate for the United States.

Caries progression in 12- to 16-year-old schoolchildren in fluoridated and fluoride-deficient areas in Brazil

Water fluoridation may reduce the rate of caries initiation, but relatively little is known of its effect on rates of caries progression through the enamel and the dentin.

OBJECTIVE

This longitudinal study was designed to compare rates of caries progression in fluoridated and fluoride-deficient areas.

METHODS

Approximal caries progression was evaluated on two standardized sets of bitewing radiographs taken at a 12-month interval of 290 12- to 16-year-old Brazilian schoolchildren. Pitts' scoring system was used to measure caries progression on conventional bitewing images. Caries progression data on the occlusal, free-smooth, and approximal surfaces of the anterior teeth were collected via clinical visual examinations.

RESULTS

The mean rate of approximal caries progression in school-children living in fluoridated areas (0.54) was found to be 62% lower than that in children from fluoride-deficient areas (1.41). When progression rates were adjusted for the initial number of decayed surfaces per subject, differences were statistically significant for lesions located at the inner half of the enamel at baseline (11% in the fluoridated areas vs. 16.5% in the fluoride-deficient areas). Multivariate logistic regression analysis revealed that residence in a fluoride-deficient area remained a significant risk factor for caries progression after controlling for caries prevalence (D1FS), number of cavitated carious lesions, whether tooth type was molar or premolar, and toothbrushing frequency.

CONCLUSIONS

These results suggest that water fluoridation reduces the rates of caries progression through the enamel and dentin, but the effect was more pronounced for lesions in the inner enamel than for those in the dentin.

Caries experience among children in fluoridated Townsville and unfluoridated Brisbane

Fluoridation of community water supplies constitutes the main public health strategy for prevention of dental caries in Australia. In recent years questions have been raised about the effectiveness of water fluoridation. The aim of this paper was to examine differences in caries experience of children aged 5 to 12 years who were lifetime residents either of Brisbane (the unfluoridated Queensland capital) or Townsville (fluoridated since 1965). Children from each city were sampled from patients of the school dental service. Dental therapists and dentists from the school dental service recorded data describing dental caries experience and parents were asked to complete a questionnaire about their children's residential history and exposure to other fluorides. Of the 18,348 children sampled, 10,195 (55.6 per cent) provided completed questionnaires, and 4588 were lifetime residents of their respective cities. Caries rates were significantly lower (P < 0.01) among children in Townsville than in Brisbane, both in the deciduous dentition (according to age 32 to 55 per cent fewer tooth surfaces affected) and permanent dentition (20 to 65 per cent fewer tooth surfaces affected). Significantly lower rates in Townsville persisted (P < 0.01) in multivariate analyses that controlled for oral hygiene practices, exposure to fluoride supplements and household income. Water fluoridation appears to provide a substantial public health benefit for children in Townsville.

Intra-oral distribution and impact of caries experience among South Australian school children

This report describes the intra-oral distribution of caries and frequency of reported toothache using data from 9690 South Australian children aged 5-15 years. School dental therapists and dentists recorded dmfs and DMFS data and a questionnaire to parents sought information about toothache and its impact. There were higher levels of caries experience in deciduous teeth (mean 6-year-old dmfs = 2.61) compared with permanent teeth (mean 12-year-old DMFS = 1.15). In the deciduous dentition: between 11.4 per cent (9-year-olds) and 37.7 per cent (5-year-olds) of total dmfs was present as untreated decay; between 39.1 per cent (7-year-olds) and 42.8 per cent (10-year-olds) occurred on interproximal surfaces; and between 2.0 per cent (10-year-olds) and 27.8 per cent (5-year-olds) occurred in anterior teeth. In the permanent dentition, the majority of permanent caries experience occurred as fillings in pits and fissures of first molars and involved a single surface. Between 11.8 per cent (5-year-olds) and 31.8 per cent (12-year-olds) of children had a reported history of toothache, although the figure exceeded 50 per cent among children with all three forms of pit/fissure, interproximal and smooth-surface caries experience. The observed pattern of caries provides the basis for continued use of fissure sealants as a preventive measure among school children.

Radiographic caries diagnosis by clinicians in Norway and Western Australia

In connection with continuing education courses in Norway and Western Australia (WA), dealing with caries diagnosis and treatment decisions, pre-tests were conducted. The pre-tests involved 433 dentists in Norway (ND), and 62 dentists (WAD) and 108 dental therapists (WAT) in WA, altogether 603 clinicians. Radiographs of 68 approximal surfaces were to be diagnosed and a treatment proposal was requested for each surface. ND showed the best overall diagnostic quality measured by the area beneath ROC-curve (P < 0.00001). The frequency of false-positive diagnoses (over-registrations) on sound surfaces varied between 7.1% (ND) and 11.9% (WAT) while the frequency of true-positive scores for lesions in the outer half of dentine varied from 57.4% (ND) to 48.1% (WAT). The mean numbers of restorations suggested by the three groups of clinicians were: ND: 14.3; WAD: 13.0; and WAT: 14.5. None of the differences was statistically significant. The proportion of sound surfaces proposed filled varied considerably between the groups, from 4.3% among Norwegian dentists to 10.6% among WAT (P < 0.0001). Of the lesions penetrating the outer half of dentine, the ND group would have restored 34.5% and the Australian clinicians somewhat fewer: WAD 25.6% and WAT 26.5%. The 11.3% of the ND who proposed more than two fillings on sound surfaces were responsible for 51.2% of the total number of filling proposals on sound surfaces. The corresponding numbers in the Australian group were 19.4% (WAD) and 33.3% (WAT) who made 73.6% and 75.7% of the restorative proposals on sound surfaces respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoride supplements: current effectiveness, side effects, and recommendations

A critical review of the literature was conducted to determine the current effectiveness of fluoride supplements in caries prevention and their role as risk factors for dental fluorosis. Use of fluoride supplements by young children is idiosyncratic and all of the studies which investigated the effectiveness of this regimen suffered from a significant drop in the number of participants receiving daily supplements. The scientific evidence supports the efficacy of fluoride supplements in caries prevention but there is weaker support for their effectiveness. Fluoride supplements are a risk factor for dental fluorosis, though their contribution to the increase in fluorosis prevalence is less than that of water fluoridation and fluoridated dentifrices because of their more limited and shorter use. There is also evidence that fluoride supplements are used inappropriately in fluoridated areas. The availability of optimal levels of fluorides in beverages in non-fluoridated communities raises the question of whether fluoride supplements are needed in the 1990s, and whether it is time to consider the total fluoride intake not only from water but also from foods, beverages, and dentifrices, when recommending supplements. A re-evaluation of the need for and dosage schedules of fluoride supplements is warranted.

Factors affecting caries experience in French adolescents

Three hundred French 14-15-yr-old adolescents were randomly selected. They were examined clinically and caries experience was determined by using the DMFS index. The aim of this investigation was to evaluate children's habits using a self-administered questionnaire, to clarify the actual influence of well-known factors such as fluoride exposure, diet, oral hygiene and socioeconomic factors on caries experience and to stress those factors of primary importance. A multiple regression analysis revealed the variables which significantly contributed to explain DMFS scores in a final model: Age, sex, frequency of sweet consumption, use of standard or high fluoride toothpastes, bleeding during toothbrushing, living in St Yorre (F- = 0.45 mg/l). At a time when caries experience is decreasing, it seems that fluoride supply, snacking and oral hygiene are still independent and significant determinants of caries experience in French adolescents.

Fluoride supplements in caries prevention: a literature review and proposal for a new dosage schedule

Fluoride supplements have contributed significantly to caries prevention; however, better information about the dynamic nature of fluoride's effect on caries has made a reappraisal desirable. It seems, from a review of the literature, that the benefit from supplement use that can be expected today in populations in low-fluoride areas is small. Possible reasons include the low caries incidence in children of recent years. Few people are willing to use supplements with sufficient regularity to achieve an effect. The principal mode of action of fluoride in supplements, topical exposure of teeth to fluoride, can be achieved with toothpastes and other means. Supplement use has been associated with dental fluorosis in children. This is displeasing to look at and may put at risk the undoubted benefits of water fluoridation if the public associates fluoride with negative cosmetic effects. This reason alone should be sufficient to compel a reconsideration of existing recommendations. An appropriate new dosage schedule for fluoride supplements should be aimed only at identifiable high caries-risk individuals, not at groups defined by age or residence and should result in much lower fluoride intake in the age span birth-eight years than many current recommendations. It should start at six months or later, expressly recommend lozenges rather than tablets for swallowing to maximize the topical effect, stipulate that the maximum fluoride ion content of a tablet be 0.50 mg to reduce the chances of fluorosis and overconsumption, and have no upper age limit, as caries risk may occur at any age. A dosage schedule meeting these requirements is proposed.

Dental status of 12-year-olds treated in private practice and a school dental service

Different ways of service provision frequently lead to different services being provided. In the School Dental Service (SDS) in Western Australia, all 5-15-yr-olds are eligible for care free of charge and most avail themselves of the service. The parents of some children choose to use private dentists (typically copaying about 50% of the cost) and their children do not attend the SDS. This study aimed to compare the dental status of 12-yr-olds who attended private dentists with that of matched children enrolled in the SDS. Non-enrolled 12-yr-olds in Perth (F- 0.8 mg/l) were identified and asked to provide background information and participate in clinical examinations. Each non-enrolled participant was matched with a classmate of the same sex. Of 184 non-enrolled children, 100 actually participated. Data on caries experience (DMFT and DMFS), fissure sealants and gingival health (CPITN) were collected by clinical examination. Analyses used Wilcoxon's signed rank, categorical and t-tests and simple linear regression. Caries prevalence was lower in non-enrolled children (0.31) than in enrolled (0.47). Caries experience was also lower in non-enrolled children (mean DMFT 0.71 vs. 0.95, ns). Enrolled children had more FT than non-enrolled (Wilcoxon, P = 0.059) but the mean number of DT in each group was 0.14. Enrolled children had somewhat fewer fissure sealants than non-enrolled children but in enrolled children there was an apparent (P = 0.056) inverse relationship between number of fissure sealants and DMFT scores; this was not the case in the non-enrolled group, suggesting better targeting of fissure sealants in the SDS.(ABSTRACT TRUNCATED AT 250 WORDS)

Should the drinking water of Truro, Nova Scotia, be fluoridated? Water fluoridation in the 1990s

An epidemiological assessment of differences in caries and fluorosis prevalences between children in Truro (< 0.1 ppm) and Kentville (fluoridated at 1.1 ppm in 1991), Nova Scotia, Canada, was completed in 1991. Out of a total of 429 children, in grades 5 and 6, in the two towns in 1991, 219 (51%) were examined. Parents answered a self-administered questionnaire investigating the sources of drinking water used by the children since birth, residence history, use of fluoride supplements, dentifrices, and other fluoride products during the first 6 yr of the life. The examination criteria differentiated between non-cavitated and cavitated carious lesions. Dental fluorosis was measured using the TSIF index. Examiner agreement was excellent. Of the children examined, 80 (36.5%) drank water (fluoridated or non-fluoridated) from municipal water systems during the first 6 yr of life. The children were assigned into five groups based upon residence history and exposure to fluoridated water during the first 6 yr of life. The percentage difference in mean DMFS scores between children in the fluoridated and non-fluoridated groups is 17% (delta DMFS1 = 0.7) when non-cavitated carious lesions are included and 39% (delta DMFS2 = 1.1) when they are excluded. The differences are not statistically significant. The significant risk factors associated with the DMFS1 and DMFS2 scores identified by a stepwise multiple regression analysis are: education level of the father, gender, and number of years of reported use of toothpaste during the first 6 yr of life. Dental fluorosis (mainly TSIF score of 1) was present in 41.5% and 69.2% of the children in the non-fluoridated and fluoridated groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental caries and its determinants among recent immigrants from rural Ethiopia

Adults (35-45 yr old) and children (5 and 12 yr old) recently arrived in Israel from rural areas in Ethiopia were examined. Caries levels were low: e.g. DMFT = 0.31 among 12-yr-olds, and 1.27 amongst adults. The 5-yr-olds were 86.8% caries-free, while 12-yr-olds were 81.8% and adults 54% caries-free respectively. According to interview data, the diet in Ethiopia had been based on local agricultural products and was almost sugar-free. The mean total count of salivary bacteria, as determined on blood agar, was 3.4 x 10(8); mean count of Streptococcus viridans, on mitis salivarius, was 6.7 x 10(7); and mean count of S. mutans, as determined on mitis salivarius with bacitracin, was 1.7 x 10(7). These levels were all high and were not significantly different from a control group of 20 Israelis. The mean number of lactobacilli, on Rogosa agar, was 2.75 x 10(4), which was significantly higher than among the controls (3.6 x 10(3). Salivary pH levels were generally similar between the Ethiopian group and the controls. Salivary flow was significantly higher for the Ethiopians (1.93 ml/min) than for controls (1.16 ml/min). Low levels of caries in this population can be attributed to an almost sugar-free diet and high salivary flow, but not to the composition of oral microflora.

How fluoridation affects adult dental caries

Oral assessments conducted to measure caries experience in adults reveal that, on average, each year of exposure to fluoridated water reduced DFS by 0.29 surfaces. Fluoridation appears to have both pre- and post-eruptive benefits.