North Texas Dentistry Volume 6 Issue 5 North Texas Dentistry Volume 6 Issue 5 | Page 5

Texas A&M College of Dentistry

Order in
Chaos

Exploring the role of stigmergy in biofilm

I

by Jennifer Eure Fuentes

n a split second, a flock of birds
alters its flying pattern, darting
across a different swath of sky. Fish
school in the ocean beneath, the silvery
glint of their scales reflecting the sunlight
all at once. Social insects such as ants
march with purpose in sudden unison toward a newfound food source.

This phenomenon is known as stigmergy,
when small entities indirectly communicate with one another. The result is selforganization, in which the system appears
to spontaneously organize. The surrounding environment has minimal control on
this process. Rather, group behavior and
shared memory cause these changes to
take place in the system itself.

One endodontics professor at Texas A&M
College of Dentistry has a hunch that stigmergy might also play a role in oral biology, through bacteria that spontaneously
organize to form biofilm, or dental plaque,
that when left uncontrolled can lead to
root canal infection or gum disease.
Dr. Poorya Jalali, clinical assistant professor, shared this hypothesis with peers during the table clinic competition at the 2016
American Association of Endodontists
Annual Session, garnering first place.
“In that table clinic we discussed how bacteria, which are very simple-minded

organisms, can
work and communicate together to create complex systems,” explains Jalali. “This indirect
communication, or stigmergy, results in
emergence, a process in which a larger existence and pattern come out from smaller
parts, and the whole pattern becomes
greater than the sum of its entities. An example of this is the emergence of consciousness and memory from a complex
system of small neurons. In other words,
biofilm is the bacterial consciousness,
which makes the colony more efficient in
resisting external forces, such as antimicrobial medicaments.”

Jalali, who joined the College of Dentistry
faculty in August 2015 and oversees
the advanced endodontics course for
third-year dental students, began developing this hypothesis with his mentor,
Dr. Gunnar Hasselgren, while obtaining
his endodontics certificate at Columbia
University College of Dental Medicine. He
even had a related concept — explaining
the unpredictable occurrence of root canal
flare-ups with chaos theory — published in
Dental Hypotheses that same year.
Further study on the topic of stigmergy
could involve growing multibacterial
biofilm, and using 3D optical techniques

Dr. Poorya Jalali
to analyze bacterial behavior, something
Jalali surmises could be likened to bees
building a hive. While grant proposals and
deeper investigation on the subject aren’t
in the works at this time, the concept still
merits takeaways.

“This stigmergic theory may not have a
clinical application for now,” says Jalali,
“but it can help us to understand the behavior of biofilm bacteria, not to target it
as a single bacteria but to target the whole
community of bacteria and how they behave together.”

“Our goal is to develop a predictable treatment approach that can be used on a broad
patient base, and to have endodontists perform these procedures in the future.”

Founded in 1905 as State Dental College, Texas
A&M University College of Dentistry in Dallas is a
nationally recognized center for oral health sciences education, research, specialized patient
care and continuing dental education.

Jennifer Eure Fuentes is a communications
specialist at Texas A&M Health Science Center
Baylor College of Dentistry. A 2006 graduate of
Texas Christian University, she has worked in the
communications and editorial field for more than
10 years.

www.northtexasdentistry.com

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