A dental 'gel' for gum disease has been developed by scientists. The topical therapy combats inflammation - potentially revolutionising treatment of a condition that affects almost half of over-30s.
It blocks the receptor for a metabolic byproduct called succinate - changing the makeup of mouth bacteria. First author Dr Yuqi Guo said: "No current treatment for gum disease simultaneously reduces inflammation, limits disruption to the oral microbiome, and prevents bone loss. There is an urgent public health need for more targeted and effective treatments for this common disease."
Gum disease is caused by bugs attacking tissue. Teeth become loose and prone to abscesses - and can fall out. In many patients the infection is so deeply lodged it can't be cleaned out by brushing or antibacterial mouthwashes.
Uncontrolled it can lead to painful and bleeding gums, difficulty chewing, and tooth loss. The lotion has been tested on mice and human cells and plaque samples cultured in the lab. It lays the groundwork for a non-invasive therapy people could apply at home to prevent or treat gum disease.
Previous studies have linked succinate to gum disease and inflammation. Guo and her Five years ago the same US team discovered elevated levels stimulate bone loss. They hope targeting it will stop the condition, known medically as periodontitis, in its tracks.
Analysis found higher levels in dental plaque and blood samples from humans and mice with gum disease, respectively. The New York University team also saw the succinate receptor was expressed. Knocking it out in genetically engineered lab rodents reduced gum inflammation and bone loss.
They also found different bacteria in their mouths. Mice with gum disease had a greater imbalance of than did 'knockout' peers Extra succinate worsened gum disease in normal mice. But the GM group were protected against inflammation, increases in unhealthy bacteria and bone loss.
Co first author Dr Fangxi Xu said: "Mice without active succinate receptors were more resilient to disease. While we already knew there was some connection between succinate and gum disease, we now have stronger evidence elevated succinate and the succinate receptor are major drivers of the disease."
The gel formulation contains a small compound that attacks the succinate protein and prevents it from being activated. Experiments on human gum cells found it reduced inflammation and processes that lead to bone loss.
Applied as a topical gel to mice with gum disease, it dampened local and systemic inflammation and bone loss in a matter of days. Treatment every other day for four weeks halved bone loss compared to peers who did not receive the gel.
It also significantly changed the community of bacteria in their mouths. Notably, the Bacteroidetes family - which include pathogens dominant in gum disease - were depleted. Senior author Professor Deepak Saxena said: "We conducted additional tests to see if the compound itself acted as an antibiotic, and found it does not directly affect the growth of bacteria. This suggests that the gel changes the community of bacteria through regulating inflammation."
Currently, dentists can clean infected areas but the tissue is often so damaged by the time it begins healing, new infection has set in. Accelerating healing could cure a chronic and recurrent disease. Further animal tests are being carried out to identify the right doseage - and any possible toxicity - before any human trials can begin.
The ultimate is a gel and oral strip that can be used at home by people with gum disease or those who are at risk. It is hoped dentists will even be able to apply a stronger, slow-release formulation to pockets that form in the gums.
Added lead author Prof Xin Li: "Current treatments for severe gum disease can be invasive and painful. In the case of antibiotics, which may help temporarily, they kill both good and bad bacteria, disrupting the oral microbiome. This new compound that blocks the succinate receptor has clear therapeutic value for treating gum disease using more targeted and convenient processes."
The study was published in the journal Cell Reports.
