Tooth decay has been much in the news in recent months. Shocking headlines about children having rotten teeth removed in hospital have accompanied calls for a national programme to tackle the problem. Into this mix has come the sugar levy, primarily targeting child obesity but with hopes for a dental collateral benefit.

Over 30 years ago, researchers at the University were the first to report a reduction in tooth decay among children in England. Since then, successive national surveys have tracked a remarkable reduction in levels of disease.

Despite this phenomenon, tooth decay is still commonplace, affecting around a quarter of young children with substantial variations linked to social inequality – with less than ten per cent of children affected in some districts in the South East, compared with nearly half in Leicester. Decay is costly to treat and has high impact on individuals. Furthermore, improvements in adult dental health have created a new challenge of ageing cohorts with natural teeth instead of dentures who are at risk of tooth decay. The outrage is justified and sugar is the cause.

The 2012 health reforms in England have created a mix of national and local responsibilities; local authorities for health promotion and NHS England for dental services, including their health-promoting aspects. One area where national government can act is policy such as advertising bans, the new industry levy on sugary soft drinks and work with manufacturers of products such as biscuits, cakes and cereals to encourage reduced sugar content. Much has been written on whether these measures will deliver, though many manufacturers of soft drinks have reduced their sugar content ahead of the levy coming into force this month and others have reduced portion size.

This drive on sugar has child obesity in its sights as part of a basket of measures and only more recently has a dental health bonus been mentioned. Anticipating reduced levels of obesity is logical if these measures prove effective, but realising a matching dental benefit might prove more challenging since it is the frequency of consumption that probably matters for teeth more than the actual amount consumed, though they are strongly associated. If, for example, people consume products containing less sugar but do so just as often then their risk of tooth decay may be unaffected. In addition, neither pure fruit juices nor sugary drinks with high milk content are affected by the soft drink levy though reformulation discussions cover the latter. It’s doubly uncertain therefore.

What are the alternatives? Local authorities are primarily responsible for funding measures to encourage people to look after their teeth better and brush with fluoride toothpaste but the evidence for public health programmes to achieve such behaviour change is sparse, though both PHE and NICE have issued guidance for commissioners. NHS England is piloting ways to use dental treatment funding to achieve a better dental health promotion focus through dental services. Both these approaches are relatively expensive and require sustained effort to maintain reach and impact.

One thing with a sound evidence base is water fluoridation, something adopted by Birmingham City Council in 1964. Only about ten per cent of England’s population is served by this measure, described by the US Centers for Disease Control as one of the ten great public health achievements of the 20th century. It’s also incredibly cheap.

Public Health England has recently, with little fanfare, published a new review of the health effects, reconfirming that there are substantial public health benefits. Perhaps we should be asking how national government can help local government extend coverage to high needs communities rather than hoping for a dental impact from an obesity initiative.