Scientists used to believe that a bacteria called Streptococcus mutans, or S. mutans, was the main culprit causing tooth decay and cavities. But researchers have discovered a new bacteria called Selenomomas sputigena that also contributes to decay. This finding opens new paths of cavity prevention programs, say the study authors.
According to Study Finds, researchers at the University of Pennsylvania School of Dental Medicine and the Adams School of Dentistry and Gillings School of Global Public Health at the University of North Carolina discovered that S. sputigena, which was previously linked to gum disease, significantly enhances the cavity-causing power of S. mutans. This unexpected partnership of the two bacterial species calls for more research into how tooth decay develops and what we can do to prevent it.
After studying plaque samples from more than 400 children between the ages of three and five, the researchers discovered that while S. sputigena does not directly cause tooth decay, it becomes trapped by the sticky structures of S. mutans and forms a protective coating on that bacteria, intensifying acid production and worsening the severity of cavities.
Dr. Hyun Koo, one of the study’s senior authors, said that the findings suggest that we need to look at ways to disrupt the protective superstructures by perhaps improving brushing techniques.
“This was an unexpected finding that gives us new insights into the development of caries, highlights potential future targets for cavity prevention, and reveals novel mechanisms of bacterial biofilm formation that may be relevant in other clinical contexts,” Koo said, in a university press release.
The findings revealed a more complex interaction between oral bacteria than was previously thought and may provide a better understanding of how childhood cavities develop. S. mutans uses available sugar in the mouth to build sticky structures called glucans that are part of the protective plaque environment. The researchers observed that S. sputigena, which has small appendages that allow it to move across surfaces, can become trapped by these glucans. Once trapped, s. sputigena proliferates rapidly, using its own cells to create superstructures that encapsulate and protect S. mutans. The result of this partnership is a greatly increased and concentrated production of acid which worsens cavities.
“Disrupting these protective S. sputigena superstructures using specific enzymes or more precise and effective methods of tooth-brushing could be one approach,” Koo says.