This week, a BBC investigation found that nine in 10 NHS dental practices were not accepting new patients, one third of council areas were not taking on any patients and only approximately 20% of practices were taking on children.

The fact that there is a shortage of dentists at the moment in the setting of a national shortage of doctors, nurses and other allied healthcare workers should not come as a surprise to anyone, particularly as dentists were not offered the same protections that we, as medical professionals, received during the pandemic. However, it raises the question: so what?

Don’t get me wrong a displaced filling or a broken crown can cause a tremendous amount of pain, and temporary fixes can in the long term exacerbate the problem. But in the grand scheme of things, how does a brighter smile compare with four-hour waits outside emergency departments?

Dental hygiene, however, is considerably more than just cosmetics and attractiveness. Functioning teeth are essential to good nutrition. Unhealthy teeth and gums can contribute to chronic pain, bad breath and low self-esteem.

There is also a clear association between poor dental hygiene and systemic health. For many the assumption is that this is a result of systemic disease, or at least confounded by self-neglect. It is easy to imagine as a patient’s cognitive decline progresses towards dementia that forgetting to brush one’s teeth would be possible, indeed expected.

An individual whose competing lifestyle commitments reduce their adherence to anti-hyperglycaemic or blood pressure tablets, is also likely to skip their oral health routine more frequently. Periodontal disease is seen as a barometer for self-care.

But could it be a causative step in systemic disease?

It has been widely published that there are more bacteria in our mouths than under the seat of the public toilets in Camden Lock (and this was before Camden was gentrified…).

On average there are 20 billion bacteria in your mouth at this moment in time. With a doubling time of only five hours, skipping brushing your teeth for just one day will result in this number topping 100 billion by tomorrow. That compares with a toilet seat having only 1,200 bacteria per square inch.

This melting pot of bacteria, cytokines and other inflammatory mediators has systemic implications. Our periodontal capillaries share a similar structure to those in the renal glomerulae.

They are fenestrated to allow better nutrition to the roots, from an evolutionary time when our teeth were continuously growing and required this support, and change through different points in life. While facilitating the rapid growth, particularly around the periodontal ligaments at the point of eruption, the holes in the capillary structure and glycocalyx do not have a one-way valve.

They allow access of the bacteria and the associated inflammatory mediators into the systemic circulation. General systemic inflammation, irrespective of source, has been implicated with higher rate of incident diabetes, and poorer glycaemic control once diagnosed, increased myocardial infarction and stroke risk and higher prevalence of dementia.

Not cleaning one’s teeth can see a five-fold increase in oral inflammatory mediators within 24 hours. These mediators serve to antagonise endogenous insulin thus tipping an individual with impaired glucose tolerance into the diabetes realms. The inflammatory response triggers amyloid deposition, implicated in the onset and progression of Alzheimer’s type dementia in a dose dependent manner.

The greater the degree of periodontal disease, the greater the risk of these associated diseases. Good oral health reduces systemic inflammation and sees a reduction in surrogate markers such as HbA1c and adverse lipid profiles, whilst the historic treatment of periodontal disease by complete enucleation (removing all of the teeth) sees a reduction in risk of incident of stroke, myocardial infarction and all-cause mortality.

While this is purely observational, and no one is suggesting we should return to the days of complete enucleation, in the absence of randomised controlled trials it would appear reasonable that we should be recommending good oral hygiene as part of a multifactorial health check. Indeed, modelling suggests a twice-daily schedule of brushing teeth and flossing will generate a similar benefit to stopping smoking or initiating a statin, at a much lower cost to the healthcare system.

Which brings us back to the absence of NHS dentists, and importantly the geographic constraints. A map of the UK, highlighting poor availability of NHS dentists, mirrors the well-established socio-economic disparities in health.

Those regions with the least access to subsidised oral hygiene expertise have some of poorest outcomes for stroke, heart disease, diabetes and other diseases associated with inflammation. This needs to be addressed as part of the UK levelling-up agenda.

The reasons are complex, our counterparts in the British Dental Association attribute the loss to private practice on the austerity squeeze on their budgets, and a change in the terms of the NHS contract that exacerbates, rather than reverses, health inequalities.

Without investment, NHS dental services will continue to falter, and this will come at the expense of our patients’ health and the services we are required to provide. It appears the confidence that a good smile pro vides is more than just the cleanliness of the teeth, but an indicator of overall bodily health.

David Strain is chair of the BMA board of science. He co-supervised a dental PhD fellowship sponsored by Colgate Palmolive approximately 15 years ago. He didn’t get so much as one tube of toothpaste himself out of it