New Tooth Decay Bacteria Identified by Dentists

According to research at the University of Pennsylvania, Streptococcus and Selenomonas sputigena are important partners in pediatric cavity formation.

By Genni Burkhart

Discovered through a collaboration between researchers at the University of Pennsylvania School of Dental Medicine and Adams School of Dentistry and at the Gillings School of Global Public Health at the University of North Carolina, a bacterium known as Selenomonas sputigena appears to play a significant role in tooth decay.

According to researchers, S. sputigena, previously associated with gum disease, can work as a partner for S. mutans, greatly enhancing its cavity-making capacity.

The study, published in Nature Communications, provides new insight into the development of tooth decay and the importance of oral health care from an early age.

Unexpected Findings

"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," says co-senior author Hyun (Michel) Koo, a Penn Dental Medicine professor of Orthodontics and Pediatrics and Community Oral Health and co-director of Penn Dental Medicine's Center for Innovation and Precision Dentistry.

Koo and the team of researchers hope to use this new knowledge to develop better ways of preventing and treating cavities, such as more effective tooth-brushing methods, among other techniques.

The study was co-authored by Kimon Divaris, a professor at the Adams School of Dentistry at UNC, and Di Wu, an associate professor at the Adams School and the Gillings School of Global Public Health at UNC.

Excellence in Collaborative Science

As Divaris explains in an article for Penn Today, "This was a perfect example of collaborative science that couldn't have been done without the complementary expertise of many groups and individual investigators and trainees."

The UNC researchers collected plaque samples from 300 children aged 3-5 years, half of whom had caries, and analyzed the samples using advanced tests with the help of Koo's lab.

In addition to sequencing bacterial genes, analyses of the biological pathways implied by the bacterial activity and even direct microscopic imaging were conducted on the samples. Furthermore, the researchers validated their findings by examining 116 plaque samples obtained from children aged 3-5.

As shown in the data, S. sputigena, although only one of several caries-linked bacteria in plaque along with S. mutans, does not cause caries on its own but has the distinctive ability to boost the caries process by collaborating with S. mutans.

Research Sparks Further Interest

As scientific research often does, this study has opened up "broad interest to microbiologists," as Koo states.

Researchers plan to investigate in greater detail how this anaerobic motile bacterium can survive in the aerobic environment of the tooth surface. This research could show how this bacterium adapts to its environment and how its presence affects oral health.

As Koo explains, this fascinating phenomenon in which a bacterium from one type of environment moves into a new environment and interacts with the bacteria living there can build remarkable superstructures. By creating these "superstructures," the bacteria can thrive in their new environment and provide an incredible example of adaptation and evolution.

If you're not yet subscribed to receive the Incisor newsletter, filled with cutting-edge dental news sent directly to your inbox twice a month, you can do so here.

Author: With over 13 years as a published journalist, editor, and writer Genni Burkhart's career has spanned politics, healthcare, law, business finance, technology, and news. She resides on the western shores of the idyllic Puget Sound, where she works as the Editor in Chief for the Incisor at DOCS Education out of Seattle, WA.


  1. The University of Pennsylvania. (2023, June 8). Dentists identify new bacterial species involved in tooth decay: Large study in children reveals Selenomonas sputigena as a key partner of Streptococcus in cavity formation. ScienceDaily. Retrieved June 22, 2023 from
DOCS Membership

Upcoming Events
Atlanta, GA skyline
August 23- 24, 2024
October 04- 05, 2024
February 28- 01, 2025

More Articles