Fluoride and Oral Health.

The discovery during the first half of the 20th century of the link between natural fluoride, adjusted fluoride levels in drinking water and reduced dental caries prevalence proved to be a stimulus for worldwide on-going research into the role of fluoride in improving oral health. Epidemiological studies of fluoridation programmes have confirmed their safety and their effectiveness in controlling dental caries. Major advances in our knowledge of how fluoride impacts the caries process have led to the development, assessment of effectiveness and promotion of other fluoride vehicles including salt, milk, tablets, toothpaste, gels and varnishes. In 1993, the World Health Organization convened an Expert Committee to provide authoritative information on the role of fluorides in the promotion of oral health throughout the world (WHO TRS 846, 1994). This present publication is a revision of the original 1994 document, again using the expertise of researchers from the extensive fields of knowledge required to successfully implement complex interventions such as the use of fluorides to improve dental and oral health. Financial support for research into the development of these new fluoride strategies has come from many sources including government health departments as well as international and national grant agencies. In addition, the unique role which industry has played in the development, formulation, assessment of effectiveness and promotion of the various fluoride vehicles and strategies is noteworthy. This updated version of 'Fluoride and Oral Health' has adopted an evidence-based approach to its commentary on the different fluoride vehicles and strategies and also to its recommendations. In this regard, full account is taken of the many recent systematic reviews published in peer reviewed literature.

Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

OBJECTIVES: To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five. DESIGN: A prospective cohort study. METHODS: At follow-up to a previous study complete data were available for 123 children; fieldwork was conducted in the child's primary school. Measurement of tooth wear used a scoring system modified from the Smith and Knight Tooth Wear Index (TWI). Tooth wear which had progressed to dentine was assessed on the occlusal surfaces of the four first permanent molars, the labial, lingual/palatal and incisal surfaces of the six upper and six lower anterior teeth; a total of 40 scoreable surfaces. Demographic data were collected from the parents, and a questionnaire on oral hygiene habits, diet and behaviours was completed by each child. RESULTS: In total 38% (n = 47) of subjects had tooth wear, if incisor teeth only were included, 33% (n = 40) had tooth wear and similarly if the occlusal surfaces of molar teeth only were included 10% (n = 12) had signs of tooth wear. Gender was significantly associated with tooth wear: males had more tooth wear. The presence of tooth wear with dentine exposed in the primary dentition was significantly associated with tooth wear on the occlusal surfaces of the first permanent molars. CONCLUSION: Males had more tooth wear than females. An association existed between tooth wear recorded at age 5 and molar tooth wear recorded at age 12. Tooth wear is a lifelong cumulative process and should be recorded in both the primary and permanent dentitions.

A lacticin 3147 enriched food ingredient reduces Streptococcus mutans isolated from the human oral cavity in saliva.

AIMS: To isolate and characterise Streptococcus mutans from Irish saliva samples and to assess their sensitivity to a food-grade preparation of the lantibiotic, lacticin 3147, produced by Lactococcus lactis DPC3147. METHODS AND RESULTS: Saliva samples collected from children with varying oral health status were screened on Mitis Salivarius agar for the presence of pathogenic streptococci. Following selective plating, 16S rDNA sequencing and Pulsed Field Gel Electrophoresis (PFGE), 15 distinct strains of Strep. mutans were identified. These were grouped according to their relative sensitivity to lacticin 3147 which ranged from 0.78 to 6.25%; relative to a sensitive indicator strain, Lactococcus lactis ssp. lactis HP. Inhibition of indicator Strep. mutans strains from sensitive, intermediate and tolerant groupings were assessed in microtitre plate assays with increasing concentrations of lacticin 3147. The concentration of lacticin 3147 required to give 50% growth inhibition correlated with their relative sensitivities (as assayed by well diffusion methodology) and ranged from 1280 to 5120 AU ml(-1). Concentrated preparations of lacticin 3147 caused a rapid killing of Strep. mutans strains in broth. Moreover, in human saliva deliberately spiked with Strep. mutans, the pathogen was eliminated (initial inoculum of 10(5)) in the presence of 40,000 AU ml(-1) of lacticin 3147. Furthermore, a food-grade lacticin 3147 spray dried powder ingredient was assessed for the inhibition of Strep. mutans in human saliva, spiked with a strain of intermediate sensitivity, resulting in up to a 4-log reduction in counts after 20 min. CONCLUSION: A food grade preparation of lacticin 3147 was effective in the inhibition of oral Strep. mutans. SIGNIFICANCE AND IMPACT OF THE STUDY: The inhibition of oral streptococci by food grade preparations of lacticin 3147 may offer novel opportunities for the development of lacticin 3147 as an anti-cariogenic agent particularly in the area of functional foods for the improvement of oral health.

Primary tooth fluorosis in 5-year-old schoolchildren in Ireland.

AIM: This was to determine the prevalence of primary tooth fluorosis in the dentitions of 5-year-old schoolchildren. A subsidiary aim was to investigate whether an association existed between the presence of primary tooth fluorosis, fluoridation status, infant feeding practices or the oral hygiene practices of the child. STUDY DESIGN: A cross-sectional and stratified by fluoridation status study. METHODS: Fluorosis was recorded using a modification of the Tooth Surface Index of Fluorosis (TSIF). Demographic data, information on infant feeding practices and oral hygiene practices were collected via a parental questionnaire. STATISTICS: Stepwise logistic regression analysis. RESULTS: Fluorosis prevalence in the fluoridated group (n=208) was 32%; 29.3% (n=61) had a modified TSIF score of 1; 2.4% (n=5) had a modified TSIF score of 2; and 1% (n=1) had a modified TSIF score of 5. In the non-fluoridated group (n=86) one child had a modified TSIF score of 1. Primary tooth prevalence of fluorosis in the entire sample (n=294) was 23%. Factors that were associated with primary tooth fluorosis were: fluoridation status (p= 0.0003, 95% CI = 5-281) and the age at which toothbrushing with toothpaste commenced (p = 0.016, 95% C.I. 1.1 - 3.8). No association with infant feeding practices was identified. CONCLUSION: The overall prevalence of primary tooth fluorosis was 23%. Lifetime residence in a fluoridated area and commencement of toothbrushing with toothpaste between 12 and 18 months of age were associated with primary tooth fluorosis. No association with infant feeding practices was identified.

Dental erosion in 5-year-old Irish school children and associated factors: a pilot study.

OBJECTIVE: To determine the prevalence of dental erosion in a stratified sample of 5-year-old children and to investigate whether demographic and dietary factors were associated. DESIGN: Cross sectional study in Cork City and County. METHODS: A sample of 202 5-year-old children stratified on fluoridation status was selected. Measurement of erosion used a scoring system and criteria based on those used in the UK. Wear on the palatal and labial surfaces of primary maxillary teeth considered to be predominantly erosive was assessed. Demographic and dietary details were collected via a parental questionnaire. Statistical analysis was stepwise logistic regression. RESULTS: In lifetime residents of fluoridated areas (n = 114) 47% had evidence of erosion; in 21% erosion had progressed to the dentine or pulp. The corresponding figures in non-fluoridated areas (n = 76) were 43% and 21% respectively. The variables significantly associated with erosion to dentine or pulp were low socio-economic status, measured by low family income and the frequency of fruit squash and carbonated drink consumption. CONCLUSION: The prevalence of dental erosion overall was 47%, in 21% erosion affected the dentine or pulp. Levels in fluoridated and non-fluoridated areas were similar. Low socio-economic status and frequency of fruit squash and carbonated drink consumption were associated with erosion extending to dentine or pulp.

Factors affecting caries levels amongst 5-year-old children in County Kerry, Ireland.

OBJECTIVE: To investigate the factors associated with high caries levels in 5-year-old children in the Kerry Community Care Area of the Southern Health Board in Ireland. DESIGN: Cross-sectional study. SETTING: County Kerry, Ireland in 1997. SUBJECTS: A random sample of 5-year-old children. METHOD: Six hundred and thirty-six 5-year-old children were examined for caries following WHO diagnostic criteria. Information on possible caries risk factors was collected by means of a parental questionnaire. RESULTS: Using multivariate logistic regression analysis the variables most significantly associated with the presence of caries were water fluoridation status, whether or not the child took the baby feeding bottle to bed, the age at which tooth brushing started and the number of sweet snacks and drinks taken in a day. While there was a wide variation in caries levels between nine geographic areas in Co. Kerry the only significant geographic variation found was between fluoridated and non-fluoridated areas. CONCLUSION: The prevalence of dental caries amongst 5-year-old children in Co. Kerry was highest in those residing in non-fluoridated communities, in those who took a baby feeding bottle to bed, in those who did not commence tooth brushing until after two years of age and in those who had sweet snacks or sweet drinks between meals three or more times per day.

A re-analysis of a caries clinical trial by survival analysis.

The decline in caries prevalence, the increases in the level of fluoride exposure, and the lack of placebo control subjects have complicated caries clinical trials in recent times. There has been a substantial increase in the numbers of subjects required for the detection of statistically significant differences between dental products, and hence, the cost of these trials has grown enormously. This study uses a new statistical approach to the analysis of the data from these trials with the ultimate aim of providing a more sensitive method of analysis. The new approach uses survival analysis, where the outcome measure is the survival time of an individual tooth surface. It exploits recent developments in the analysis of clustered survival data where survival times within the same cluster or subject are correlated. To illustrate, the new method of analysis was used for the North Wales, UK, caries clinical trial. It is concluded that survival analysis uses most of the data available in a caries clinical trial, an outcome measure that is easily understood and may lead to a more sensitive method of analysis.

A caries susceptibility classification of tooth surfaces by survival time.

Individual tooth surfaces have vastly different susceptibilities to caries and this susceptibility also varies over time. The aim of this study was to develop a method of grouping tooth surfaces into a caries susceptibility classification based on their survival experience. The data used in the study were from a 3-year caries clinical trial. The definition of survival time was taken to be the time from the start of the trial to when a surface is recorded as decayed or filled. Cluster analysis was used to divide the tooth surfaces into groups in such a way that surfaces in the same group have similar survival time distributions. The 13 groups identified were ordered from 1 to 13 starting with the group with the shortest survival time, i.e. the occlusal surfaces of the four first molars. Approximately 80% of symmetrical pairs of tooth surfaces were in the same group. The groups obtained using cluster analysis were compared to groups defined using dental/anatomical criteria. It is concluded that the cluster analysis method developed for grouping the tooth surfaces cn provide a useful descriptive measure of caries susceptibility which can be applied to data from any longitudinal study of caries.

Variation of salivary flow rate in adolescents.

Forty-three children living in North Wales, an area with a temperate climate, were involved in this study from September 1990 until June 1991 inclusive. By standardizing the method and timing of collection the effect of external factors on the salivary flow rate was minimized. Flow rate was assessed once a month. Of the original group of 43, 18 attended at each occasion; these were termed the "regular attendees". Repeated-measures analysis of variance indicated that unstimulated salivary flow rate varied within an individual over time in both the total (43, p < 0.001) and the regular groups (18, p < 0.001). This relation remained when the initial September and October measurements were excluded (p < 0.05, n = 43). When the subgroup, the regular attendees (n = 18), was considered, this relation almost reached statistical significance when September was excluded (p = 0.052) and when both months were omitted the association was no longer evident (p = 0.094). Similar to previously published results from a study of individuals in a subtropical climate, salivary flow-rate variation was inversely associated with ambient temperature in both the total (n = 43) and the subsection of regular attendees (n = 18) (p < 0.05).

Anti-calculus activity of a toothpaste with microgranules.

OBJECTIVE: The objective of the trial was to determine the efficacy of the proven anticalculus active system (zinc citrate trihydrate [ZCT] and triclosan), when the ZCT is delivered from microgranules incorporated in a silica-based toothpaste containing 1450 ppm F as sodium fluoride. DESIGN: A monadic, single-blind, two phase design clinical trial was used to compare the effect of the test and a negative control fluoridated toothpaste on the formation of supragingival calculus. SUBJECTS AND METHODS: Male and female calculus-forming volunteers, aged 18 or over, were recruited for the study following a 2-week screening phase. All subjects were given a scale and polish of their eight lower anterior teeth at the start of both the pre-test and test phases. Subjects were supplied with a silica-based 1450 F ppm fluoridated toothpaste with no anti-calculus active for use during an 8-week pre-test phase. Calculus was assessed at the end of the pre-test and test phases using the Volpe-Manhold index (VMI). Subjects were stratified according to their pre-test VMI score (8-10, 10.5-12, > 12) and gender and then allocated at random to test or negative control toothpaste groups. Subjects with < 8 mm of calculus were excluded from further participation. MAIN OUTCOME MEASURE: The outcome variable was the mean VMI score for the test and negative control groups. RESULTS: The test toothpaste caused a statistically significant 30% reduction in calculus compared with the control paste after a 13-week use. No adverse events were reported during the study. CONCLUSION: The incorporation of the ZCT in microgranules did not adversely affect the anticalculus activity of the new formulation.

A three-year clinical trial of a combination of trimetaphosphate and sodium fluoride in silica toothpastes.

The relative efficacy of NaF silica toothpastes containing 1000 ppm fluoride and 1500 ppm fluoride in the control of dental caries is not clear-cut. Also, it has not been established that incorporation of trimetaphosphate (TMP) improves the anticaries activity of NaF toothpastes. A three-year clinical trial was conducted to test the hypotheses that: (i) the anticaries activity of NaF toothpastes containing 1500 ppm F was greater than that of NaF toothpastes containing 1000 ppm F, and (ii) inclusion of TMP improved the efficacy of NaF silica pastes. Subsidiary aims included determination of whether frequency of toothbrushing and method of rinsing after brushing were correlated with caries increments. The study involved 4196 children aged 11 to 12 years at outset. These participants had been selected from a pool of 7374 potential subjects on the basis of caries experience and dental eruption pattern. They were stratified by sex, examiner, and presence of calculus and caries, and were allocated at random to one of the four toothpastes under study. Using mirror and probe and also FOTI, we carried out clinical examinations at baseline and annually thereafter for 3 yrs. Bitewing radiographs of a subset of children were taken at baseline and at the end of the study. The outcome measure for the study, DMFS increment, was defined as the increase in caries over 3 yrs, taking into account changes occurring on individual tooth surfaces. Data for 3467 subjects were available for analyses at both baseline and year 3 examinations. Radiographs were taken for 1942 subjects at both baseline and year 3 examinations. The mean three-year clinical-only DMFS increment for the subjects using 1500-ppm-NaF pastes was 3.93, which was 6% lower than the corresponding mean of 4.19 for the 1000-ppm-NaF pastes. There was no significant difference between the mean DMFS increment for those using paste with or without TMP. Subjects who claimed to brush more frequently or who claimed not to use a tumbler to rinse after toothbrushing had lower three-year DFMS increments.

Costs in providing facilities for treatment of handicapped patients under general anaesthesia.

The cost of providing dental treatment for severely mentally/physically handicapped patients under general anaesthesia in a specially designed unit are investigated in this study. The costs involved in the provision of such treatment were found to be high at 613 IR Pounds per patient. It is recommended that the full potential of primary care services for handicapped patients be developed in order to reduce the use of these necessary, but expensive secondary care facilities. It is also recommended that such facilities should be shared with other services in order to reduce overall costs.

Water fluoridation in Ireland.

The basis for the constitutional challenge to the Health (Fluoridation of Water Supplies) Act 1960 in the Republic of Ireland and the judgements of the High Court and Supreme Court are described. Pre-fluoridation baseline surveys and various surveys conducted over the last 30 years in the Republic of Ireland show, that amongst of fluoridated communities, children experience lower levels of dental caries and adults retain more of their natural teeth when compared with residents of non-fluoridated communities.

A photographic study of developmental defects of enamel in Brazilian school children.

The aims of this study were, to record developmental enamel in three areas of Brazil with a range of fluoride concentrations in their drinking water and to consider the association between clinical and photographic methods of recording enamel defects. A total of 457 subjects were examined from areas with less than 0.01, 0.7 and 2-3 ppm F in their drinking water. From the photographs, the prevalences of subjects with TF scores of one or more for the upper permanent central incisors were 7 per cent, 52 per cent and 92 per cent respectively for the three areas. The prevalence of demarcated opacities decreased with increasing fluoride levels in the drinking water (p < 0.008). There was substantial agreement between the Thylstrup Fejerskov (TF) scores using clinical and photographic methods (kappa = 0.63). However, prevalences of TF scores of one or more were higher using the photographic (44.9 percent) than clinical (41.4 percent) method (p < 0.01). The results of this study were compared with one undertaken in the United Kingdom and Ireland which also used the same photographic method. Although the prevalences of TF scores of one or more were similar in the areas with near 'optimal' levels of fluoride in the drinking water, in the groups with levels of fluoride less than 0.1 ppm the prevalence of subjects with TF scores of one or more was higher in the United Kingdom population than in Brazil. This study demonstrates the utility of photographic methods of collecting information on enamel opacities over a wide range of fluoride exposure. Results suggest that for the groups from areas with low levels of fluoride in the drinking water the overall fluoride exposure of the UK children was greater than the Brazilian.

A photographic study of developmental defects of enamel in Brazilian school children / Um estudo fotografico do crescimento dos efeitos do esmalte em crianças estudantes brasileiros

Los objetivos de este estudio fueron los de registrar los defectos de desarrollo del esmalte en tres áreas de Brasil con diferentes concentraciones de fluoruros en el agua de bebida y considerar la asociación entre los métodos clínicos y fotográficos en el registro de defectos del esmalte. Se examinó un total de 457 individuos de zonas con menos de 0,01, 0,7 y de 2-3 ppm de F en el agua de bebida. En el estudio fotográfico, la prevalencia de sujetos con un índice de Thylstrup Fejerskov (TF) de uno o más en los incisivos centrales superiores fue de 7 por ciento, 52 por ciento y 92 por ciento respectivamente, en cada una de las tres zonas. La prevalencia de opacidades demarcadas disminuyó con el aumento del nivel de fluoruros en el agua de bebida (p<0,008). Hubo un acuerdo sustancial entre los valores del índice TF al usar métodos clínicos y fotográficos (kappa=0,63). Sin embargo, la prevalencia de los valores TF mayores de uno fue más alta al usar el método fotográfico (44,9 por ciento) que el clínico (41,4 por ciento) (p<0.01). Los resultados de este estudio se compararon con los de uno realizado en el Reino Unido y otro en Irlanda en los que se usó el miesmo método fotográfico. Aunque la prevalencia de los valores del indice TF de uno o más fue similar en las zonas con niveles casi óptimos de fluoruro en el agua de bebida, en los grupos con niveles de fluoruro menores de 0,1 ppm, la prevalencia de sujetos con valores TF de uno o más fue mayor en la población del Reino Unido que en la de Brasil. Este estudio demuestra la utilidad de los métodos fotográficos para el registro de datos sobre opacidades del esmalte en casos de exposición a un amplio rango de concentraciones de fluoruro. Los resultados sugierem que en los grupos provenientes de zonas con bajos niveles de fluoruro en el agua de bebida, la exposición total a fluoruros fue mayor entre los ni±os del Reino Unido que en los de Brasil

Identification of areas with high levels of untreated dental caries.

In order to examine the geographical variation of dental health within 10 county districts in North Wales, 3538 children were examined. The associations between three demographic indicators, based on the 1981 OPCS census, and dental health outcomes were assessed for electoral wards within the county districts. The Townsend and Jarman indices were the first two indicators employed and the third was based on a mathematical model representing the variation in the mean number of untreated decayed surfaces per person for the wards. This model was developed using the children examined in the five most westerly county districts. Using the data derived from the five most easterly county districts, the three indicators were assessed. All three showed strong correlations (r > or = 0.88) with dental health. These results indicate that measures of dental health based on large administrative units may obscure variation within them. It is concluded that geographical methods of this type may be useful for targeting dental resources at small areas with high levels of need.

Drinking water fluoride levels, dental fluorosis, and caries experience in Brazil.

OBJECTIVES: The main aim of this study was to consider the association between water fluoride levels and caries prevalence in three Brazilian populations. METHODS: A total of 457 6-12-year-old lifetime residents from three economically deprived groups with 2-3, 0.7, and less than 0.01 ppm F in their water supplies were examined. Dental caries was recorded on permanent upper central incisors and first molars and all primary teeth (dmft). RESULTS: There was a significant trend (P < 01) for the mean dmft to decrease with increasing levels of fluoride in the drinking water. Caries experience in the six permanent teeth was significantly lower (P < 01) in the area with 0.7 ppm F than in the other two groups For the 2-3 ppm F group significantly more caries was found in subjects with higher TF scores (P < 05). CONCLUSION: Optimization of fluoride levels in the drinking water remains a valuable dental public health measure in Brazil.

The prevalence of dental caries in Europe 1990-1995. ORCA Saturday afternoon symposium 1995.

Caries prevalence data from recent studies in all European countries showed a general trend towards a further decline for children and adolescents. However, in several countries with already low caries prevalence in primary teeth, there was no further decrease. Regarding the permanent dentition, further reductions were observed in the 12-year age group, these being even more evident at the ages of 15-19 years. In some Central and Eastern European countries, caries prevalence in children and adolescents was still high. Few data were available on young adults, but the benefits of prevention are becoming manifest. The available data on the use of toothbrushes, fluorides and other pertinent items provided few clues as to the causes of the decline in caries prevalence.

The association between area deprivation and dental caries in groups with and without fluoride in their drinking water.

In order to determine the association between social background and dental caries for subjects living in areas with and without fluoride in the drinking water, lifetime residents from Anglesey (0.7 mg/l F-, n = 196) and Chester/Bala (< 0.1 mg/l F-, n = 267) were examined. The mean age overall was 14.1 (+/- 0.3) years. For the Anglesey group, when differences in material deprivation were controlled, the mean DMFS was 2.9 compared with 4.3 in Chester/Bala, a difference of 33 per cent. Using multiple linear regression it was found that there was no interaction between material deprivation and water fluoridation. This suggested that absolute differences in dental caries between these areas with and without fluoride in the drinking water were similar for different strata of deprivation. It follows that percentage reductions in dental caries resulting from fluoridation of water supplies tended to be less in deprived than non deprived groups.