Fluoride and oral health

Transcription

1 Fluoride and oral health Key points In communities with a reticulated water supply, water fluoridation is the most effective and efficient way of reducing the prevalence of dental caries. In 1998, 57 percent of New Zealanders receiving reticulated water had their water fluoridated. Water supplies serving a total of about people will need to commence fluoridation if the target is to be met. This is unlikely to be achieved by Fluoride toothpaste In percent of toothpaste sold contained fluoride. The target of at least 97 percent market share by toothpastes containing fluoride by 2000 will possibly be achieved. In 1997 the mean missing or filled permanent teeth (MFT) scores among Form 2 children were slightly higher at 1.6 compared to 1.5 in Form Two (MFT) scores appeared to worsen in 1994?97, ending a sustained period of improvement. An improvement of 15 percent per year during is required to meet the target for all children. Targets To increase the size of the population receiving fluoridated water to 70 percent of the population on reticulated water supplies by Fluoride toothpaste To increase the percentage of fluoride toothpaste out of all toothpaste sold in New Zealand to 97 percent or more by To reduce the average number of missing or filled permanent teeth in Form 2 children to one per child or less by To reduce the average number of missing or filled permanent teeth in Form 2 Mäori children to 1.4 per child or less by Progress on Health Outcome Targets

2 Progress towards the target In May percent of New Zealanders received their water from a reticulated supply included on the Water Information New Zealand (WINZ) database (Figure 1). Of these 57 percent had their water fluoridated. This is similar to the 1997 estimate of 56 percent (Ministry of Health 1998). Figure 1: Percentage of the population on a reticulated water supply and receiving fluoridated water, % 36% 48% Population receiving reticulated fluoridated water* Population receiving reticulated non-fluoridated water Population not receiving reticulated water Source: Institute of Environmental Science and Research 1999 * This corresponds to 57 percent of the total population receiving fluoridated water. WINZ includes data on many small community supplies that were not previously included. Therefore, although the 1997 and 1998 estimates of 56 and 57 percent fluoridation of reticulated supplies are significantly lower than earlier estimates, they are considered to be more reliable (Ministry of Health 1998). Fluoridation of supplies serving about people is required to meet the target. This figure represents one-third of the population currently receiving reticulated but nonfluoridated drinking-water. It will require approximately an 11 percent increase in the percentage of the population on a reticulated water supply and receiving fluoridated water. The target level appears very unlikely to be achieved by 2000 given that very few large supplies have changed fluoridation practice in recent years. Both domestic and international research have shown that the benefits of water fluoridation tend to be greatest for people most at risk of dental caries such as those groups who do not brush their teeth daily or who do not always use a fluoride toothpaste. 46 Progress on Health Outcome Targets 2000

3 Fluoride toothpaste The estimated proportion of toothpaste sold that contains fluoride is 96 percent for the 52 weeks to mid-april 1999, up from 95 percent in the 26 weeks to mid-april These estimates are higher than the estimates of between 85 and 92 percent for 1991 and 1996 (Figure 2). However estimates prior to 1997 were probably too low due to incomplete information on which brands of toothpaste contained fluoride. Figure 2: Percentage (by volume) of toothpaste containing fluoride, 1991? Percent Target * 1999** 2000 Year Source: Ministry of Health 1999 Note: 1998* refers to 26 weeks to mid-april 1998, 1999** refers to 52 weeks to mid-april The 2000 target of 97 percent will be met with a less than a 1 percent increase. In 1997 the mean score of MFT in Form 2 children was 1.6 compared to 1.5 in The average number of MFT in Form 2 children decreased from 5.1 in 1980 to a low of 1.3 in 1994 but since then the MFT score has been rising slowly but steadily (Figure 3). There are, however, some questions about the quality of the current data. MFT scores improved steadily through the 1980s. The rate of improvement slowed in the early 1990s and has now reversed. An improvement of 15 percent each year for the period 1998? 2000 is required to meet the target for all children, and of 8 percent per year for Mäori children. Progress on Health Outcome Targets

4 Figure 3: Average number of missing or filled permanent teeth, Form 2 children, ; Mäori Form 2 children, 1995? 97 6 Percent Targets Year Mäori children All children Source: Ministry of Health 1999 Note: Data for Mäori children are available only from 1995 (not all regions). The data for 1997 for Mäori children refer to the Central region only. In recent years there has been greater use of radiography, which has enhanced sensitivity for detecting caries in school dental services. This is likely to be at least a partial explanation for the recent rise in MFT scores. If this is the case, the downward trend may possibly resume, albeit from a higher baseline level. An alternative hypothesis is that socioeconomic marginalisation of substantial sections of the New Zealand population has caused MFT scores to worsen (Thomson 1994). With the target indicator moving in the wrong direction, the target for all Form 2 children appears unlikely to be met. Whether the target for Mäori children is likely to be met cannot be assessed at this stage because a sufficient time series of consistent data does not exist and the data for Mäori children are incomplete. Indicators?? Size of population receiving fluoridated water as a percentage of the population on reticulated water supplies.?? Percentage (by volume) of toothpaste sold that contains fluoride.?? Average number of MFT in Form 2 children. Data sources Information on all public drinking-water supplies is collected by local public health services and is held in the WINZ database maintained by the Institute of Environmental 48 Progress on Health Outcome Targets 2000

5 Science and Research Limited (ESR) on behalf of the Ministry of Health. WINZ includes data on the number of people served by each supply and the supply s fluoridation status. Both the quality and usefulness of data about fluoridated water supplies in New Zealand have improved in recent years through the replacement of earlier databases with the WINZ database system. Since 1996 this database has provided reliable estimates of the target indicator and a time series is being developed. The target indicator does not capture use of fluoride among populations without reticulated water supplies? that is, those with private supplies or with very small community supplies (approximately 16 percent of the total population). Neither does the indicator capture discretionary use of fluoride at the household level in the form of tablets added to water in areas supplied with non-fluoridated water. Fluoride toothpaste The percentage of toothpaste sold that contains fluoride is calculated by matching the Ministry of Health s data on fluoride content of toothpastes with data on sales obtained from a market research company (AC Nielsen Ltd). Sales data used in this target refer only to sales through supermarkets. Some toothpastes, especially non-fluoride brands, are sold through pharmacies and health product shops or by direct distribution. For this reason the true consumption of fluoride toothpastes is probably overestimated to some extent. However supermarkets still account for the vast majority of sales and these data are of sufficiently high quality to monitor trends from year to year. The percentage of toothpaste sold that contains fluoride is a good indicator of exposure to fluoride from toothpaste for the whole population. However, significant proportions of some age groups do not use any toothpaste on a regular basis (Hunter et al 1992). Information on the number of MFT for children aged five years and in Form 2 (approximately 12 years old) is collected by Hospital and Health Services school dental services. The most recent data available are for Information provided by school dental services on the dental health status of children is of high quality. About 95 percent of Form 2 children are seen by school dental services. Separate data for Mäori children have only been reported for some regions each year. The MFT score for all Mäori children is estimated from these limited data. The indicator used for this target, MFT, does not include decayed unfilled teeth since data for these are not available. Progress on Health Outcome Targets

6 References Institute of Environmental Science and Research Limited Unpublished data from Water Information New Zealand database. Wellington: Institute of Environmental Science and Research Limited. Hunter PBV, Kirk R, de Liefde B The Study of Oral Health Outcomes. Wellington: Health Research Services, Department of Health. Ministry of Health Progress on Health Outcome Targets: Te Haere Whakaimua ki ngä Whäinga Hua mö te Hauora. The state of the public health in New Zealand Wellington: Ministry of Health. Ministry of Health The Oral Health Strategy. Wellington: Ministry of Health. Thomson WM Social class and socioeconomic status (letter). NZ Medical Journal 107: Progress on Health Outcome Targets 2000