In undertaking a new project on kids in this country, finding out what makes life good for all of them (not just some) we are looking at some of the policies that affect kids disproportionality, especially in health. Earlier we covered immunisation, in this blog we look at community water fluoridation. Today’s blog will look at why fluoride is so effective, particularly for our kids in need. In the next blog we will look at why letting local councils decide upon and deliver water fluoridation is just plain crazy.
Fluoride occurs naturally in our ground water
Fluorine is the naturally occurring element that forms the basis of fluoride. Throughout NZ fluoride is found to naturally occur in our ground water at between 0.1 – 0.3 parts per million (ppm). It also occurs in black tea at 1 – 3 ppm and in seawater at 1.3 ppm.
At slightly higher levels, fluoride in water prevents tooth decay
When fluoride is present in water at between 0.4 and 1 ppm (about 1 cup in a swimming pool full of water or 7 drops in a full bath tub), it prevents and reverses dental decay.
The fluoride in water helps teeth in 3 ways:
- It promotes remineralisation of teeth. Where decay is present fluoride helps draw in minerals (eg. Calcium) to rebuild the decayed area.
- It creates a better, stronger tooth surface. Where remineralisation has occurred the new area is actually harder and more resistant to decay
- It helps reduce the production of acid in the mouth by bacteria.
High quality international research shows water fluoridation reduces the number of decayed, missing and filled teeth by, on average, two and a quarter teeth per child and on average increases the proportion of children completely free from tooth decay by 15%. Evidence from NZ shows significantly less decay (30–40 percent less) in the teeth of children living in fluoridated areas, compared to those living in non-fluoridated areas.
About half of our population lives in areas with fluoridated water
Despite this strong evidence, only half our population has fluoride to the necessary level in their drinking water. Fluoridated community water supplies (fluoridated to between 0.7 and 1 ppm) are found throughout NZ, but mainly in our more densely populated areas.
Fluoridating our water to the levels we do is safe (cosmetic mottling of the teeth enamel is the one side effect that is observed in a small number of people), cheap to the taxpayer, and has no burden on individual families – ESR research for NZ shows it is cost effective for communities as small as 1000 people.
Rotten teeth are mainly a poor kid’s problem, which has a cost-effective solution.
Poor kids and Maori and Pacific kids suffer more tooth decay than other kids in NZ. However fluoridated water – a cheap, universal intervention not only reduces dental decay equally for all kids, but it actually works to close the gap in tooth decay between kids1. This is one of the great benefits of water fluoridation (as opposed to other types of fluoridation such as toothpaste) – it’s equal impact. It is an intervention that costs the kids nothing and requires no behavioural changes from them or their parents.
The kids that need fluoridation most are the ones missing out
Kids living in poorer families have more rotten teeth and are much more likely to be without fluoridated drinking water. This is sometimes due to the cost and practicalities of fluoridating smaller water supplies in less populated areas. Sometimes it is down to vocal (but often minority) opposition. We will look at both issues in a forthcoming blog when we review the silly way we make decisions on fluoridation. The point to focus on here is that regardless of the reason, these are precisely the kids that should not be missing out on fluoridated water.
To give everyone choice can’t we just educate kids to brush their teeth?
Education does not work to change tooth brushing behaviour in kids, and while fluoridated toothpaste is an important part of good oral health, along with limiting sugary drinks and food, community water fluoridation is the backbone of a population with good oral health.
Rotten teeth get pretty expensive down the track for all of us
So poor kids in this country are at greater risk of tooth decay, but are less likely to receive the benefits of fluoridated water, which could improve their plight. This is bad news for all of us because tooth decay in childhood becomes a problem in adulthood. When baby teeth decay it actually increases the chance of getting decayed teeth as an adult, and these are expensive to fix. Hands up who hates the dentist not just because of the drilling in the teeth but the drilling into your bank account?
For poor kids who become poor adults, they are doubly disadvantaged by a lack of fluoridation – they are much more likely to have dental problems and much less likely to be able to afford to pay for them. Recently we heard that WINZ has stopped advancing those on a benefit to help them pay for dental procedures over $300, and the public system only subsidises one tooth extraction per person (after a $40 fee). This means there are a lot of people out there suffering with painful, abscessed teeth because they just don’t have the cash. We have traditionally underestimated the economic impact of serious tooth problems. Yet for kids bad teeth can cause developmental problems, school performance and behaviour issues, and sometimes serious disability. For adults it causes stress in families, diminished quality of life and reduced participation in work due to chronic pain. Eventually it costs all of us quite directly via emergency care in hospitals.
Community water fluoridation should be a basic right and it should be expanded
Rotten teeth in both children and adults are debilitating and humiliating. Fluoridating in water is not only a lot more cost effective than fixing stuffed teeth but it is much fairer. Is New Zealand the type of place where we think it is okay for those without money to have to suffer the pain and indignity of untreated rotten and abscessed teeth when there is a simple cost effective preventive measure?
What we need to do, as the Prime Minister’s Chief Science Advisor, and the NZ Dental Association has advised is to expand our community water fluoridation. The current system is not working, and is not fair, but there is a way to fix it: we will look at this and the convoluted issue of ‘local choice’ in the next blog. McDonagh M, Whiting P, Bradley M, Cooper J, Sutton A, Chestnutt I, et al. A systematic review of public water fluoridation. York: NHS Centre for Reviews and Dissemination, University of York, 20  Royal Society of New Zealand & Office of the Prime Minister’s Chief Science Advisor. Health effects of water fluoridation: A review of the scientific evidence Royal Society of New Zealand, Office of the Prime Minister’s Chief Science Advisor, 2014. http://www.pmcsa.org.nz/wp-content/uploads/Health-effects-of-water-fluoridation-Aug2014.pdf