In 2009 the Ministry of Health carried out an oral health survey to look at dental health across the nation. The results were published in 2010 in the MoH publication Our Oral Health
The Ministry of Health have been claiming the fluoridation reduces dental by 40%. Under the Official Information Act, the MOH admitted that they got this figure from the 2009 Oral Health Survey.The online “key findings” say water fluoridation reduced dental decay and did not increase dental fluorosis rates.
However, within the publication itself it states:
“It is important to note that it was not one of the objectives of the 2009 NZOHS to compare the oral health status of people by fluoridation status, and therefore the survey cannot be taken as a fluoridation study. The following results are a snapshot in time and constitute an ecological analysis based on current place of residence. As such they do not take into account lifetime exposure to fluoridated and non-fluoridated water supplies. Individuals who currently live in fluoridated areas may have spent time in non-fluoridated areas, and the reverse is also true. Furthermore, there may be other confounding factors that haven’t been taken into account.”
It may have been valid for the Ministry of Health to take a snap shot in time if they were looking at a large population. But the 2009 Oral Health Survey only contained about 60 children in each age group. In comparison, the New Zealand School Dental statistics that are collected every year, and freely available on the MoH website have about 45,000 children in each age group.
Therefore, it is misleading for the MoH, or anyone else, to use data from the 2009 Oral Health Survey.
Read the Oral Health Survey.