Autoimmune disorders often get talked about in biological dentistry. Usually, it’s in reference to things like “silver” mercury amalgam fillings, infected root canal teeth, or areas of osteonecrosis in the jaw — all factors that may add stress to an already stressed-out immune system that’s struggling to maintain balance.
But that’s not the only potential link between dental conditions and autoimmune disorders. In fact, new research shows that it could also involve some very common oral problems.
Recently published in BMC Oral Health, the study drew on data from more than 451,000 participants in the UK Biobank, a long-running research project that follows the health of selected UK residents over time. Participants were classified by whether they’d reported any of five oral health problems — painful/bleeding gums, mouth ulcers, toothache, dentures, and loose teeth — or not. The research team then looked at who had gone on to develop any of 39 autoimmune conditions.
That last part is key. The study wasn’t just documenting how often dental problems and autoimmune disease showed up in the same people. By looking at oral health first and then tracking autoimmune diagnoses over time, the researchers could ask whether those oral health problems were associated with later risk.
And they were. Those who reported at least one oral health problem had a 11% greater risk of developing an autoimmune disorder later. The more oral problems, the greater the risk.
Painful gums showed the strongest association of all. Those reporting gum problems had a 39% higher risk of developing an autoimmune condition. Mouth ulcers and toothaches were also linked with a higher risk — just not as high as painful gums.
Of course, painful or bleeding gums are a common sign of gum disease, as are gums that are puffy, red, or tender. In that early stage — gingivitis — the inflammation is confined to the gums and can still be reversed. Not so once gingivitis has progressed to periodontitis. At that point, inflammation affects the tissues and bone that support the teeth. As it worsens, gum tissue can pull away from the teeth. Bone can be lost. The teeth may loosen in their sockets.
A good deal of other research has already highlighted one particular link between periodontitis and the autoimmune condition of rheumatoid arthritis, or RA. People with RA are more likely to have periodontitis than people without it, and researchers have been investigating the biological connections between the two for years.
The two diseases have some important things in common. Both involve chronic inflammation and the progressive destruction of tissue and bone. But researchers have also been looking at more specific mechanisms that could help explain the relationship.
One of the most intriguing involves Porphyromonas gingivalis, a bacterium strongly associated with periodontitis. P. gingivalis produces an enzyme that can citrullinate proteins, changing their structure. In someone susceptible to RA, those altered proteins may contribute to the production of autoantibodies — antibodies that mistakenly target the body’s own tissues.
While this doesn’t mean that periodontitis actually causes RA, it does suggest why the current study found such elevated autoimmune risk in people with painful or bleeding gums.
And RA isn’t the only linked condition. The new study found that oral health problems were associated with seven specific conditions, including Sjögren’s disease, psoriasis, pernicious anemia, and lichen planus.
Again, it’s not that the research is showing that poor oral health can cause such systemic issues. In fact, the relationship can run the other way, too. Autoimmune disease can affect the mouth, and some of the same underlying processes may contribute to both.
What it does reinforce is something we see every day in biological dentistry: Symptoms in the mouth don’t exist apart from the rest of the body. Pain, inflammation, bleeding, and other changes are signals that something is going on. The question is what those signals may be telling us about the bigger picture.
For someone living with an autoimmune condition — or dealing with symptoms that haven’t yet yielded clear answers — that makes oral health another piece of information worth considering. Existing dental conditions, inflammation, past dental work, health history, and what’s happening elsewhere in the body can all help us understand the bigger picture.
And if we find periodontitis? Then, of course, we need to treat it.
The good news is that periodontal treatment has come a long way. Today, we have options that can target diseased tissue and bacteria much more precisely while supporting the body’s own healing response.
But we’re getting ahead of ourselves. We’ll save that conversation for next time.