Scientists have made an important discovery that could change the way we understand and prevent tooth decay.
Researchers from the University of Pennsylvania School of Dental Medicine and the University of North Carolina found that a bacterial species called Selenomonas sputigena—previously known only for its role in gum disease—also plays a major role in causing cavities.
For years, the main bacteria blamed for tooth decay has been Streptococcus mutans. This bacteria forms a sticky layer called plaque on the teeth.
The plaque traps sugars from food and turns them into acid, which damages tooth enamel and causes cavities. But this new study shows that S. mutans isn’t working alone.
The researchers discovered that S. sputigena helps make the process worse. This bacteria has long been linked to gum problems, but it wasn’t thought to be involved in tooth decay.
Now, using advanced tools to study dental plaque, the team found that S. sputigena often appears in the mouths of children with cavities—alongside S. mutans.
What’s especially interesting is how the two bacteria work together. S. mutans builds sticky structures using sugars, and S. sputigena gets caught in these structures.
Once it’s trapped, it grows fast and creates a protective environment that helps S. mutans survive longer and produce more acid. This teamwork leads to deeper and more damaging tooth decay.
This discovery gives scientists a clearer picture of how cavities form and may explain why some cases of tooth decay are more aggressive than others. It shows that the problem isn’t just about one kind of bacteria—it’s about how different bacteria work together.
Understanding this partnership opens the door to new ways of preventing cavities. For example, future treatments could focus on breaking up the structures that S. sputigena helps build, or on targeting both bacteria at the same time. Even improving brushing techniques to better remove this sticky plaque could help.
The researchers now plan to explore how S. sputigena, which normally lives in places with no oxygen (like under the gums), ends up on the tooth surface, where there is oxygen. This may help scientists learn more about how bacteria adapt and interact in different parts of the mouth.
Tooth decay remains one of the most common health problems in the world, affecting people of all ages. Better understanding of the bacteria behind it could lead to smarter treatments, better dental products, and healthier smiles for millions.
The study was published in Nature Communications and highlights the power of collaboration between different scientific teams. It’s a reminder that even common problems like cavities still hold secrets—and solving them can lead to major improvements in public health.
If you care about tooth health, please read studies about an important causes of tooth decay and gum disease, and common tooth disease that may increase risks of dementia.
For more health information, please see recent studies about mouthwash that may increase your tooth damage, and results showing this diet could help treat gum disease.
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