In humans, actual bacterial colonies in gum tissue can cause gingivitis, or gum
inflammation. Gingivitis can develop into periodontal disease, which
involves a more serious infection that breaks down the bones and tissues
that support teeth.
Now, researchers have developed computer simulations showing how lasers
attack oral bacterial colonies, suggesting that benefits of using lasers
in oral debridement include killing bacteria and promoting better
‘Computer simulations showing how lasers attack oral bacterial colonies have been developed by researchers.’
In a study published in the journal Lasers in Surgery and Medicine
the researchers show the results of simulations depicting various laser
wavelengths aimed at virtual bacterial colonies buried in gum tissue.
"The paper verifies or validates the use of lasers to kill bacteria
and contribute to better health following periodontal treatments," said
co-author Lou Reinisch, associate provost for academic affairs at New York Institute of Technology.
Drawing on his background in physics, optics, and calculus,
Reinisch, an expert in laser surgery and an associate editor with the
journal, created mathematical models based on optical characteristics of
gum tissues and bacteria. He then produced simulations of three
different types of lasers commonly used in dentistry and their effects
on two types of bacterial colonies of various sizes and depths within
the gum models.
"One of the questions we asked is how deep could the bacteria be and
still be affected by the laser light," said Reinisch. The simulations
indicate that 810 nm diode lasers, when set to short pulses and moderate
energy levels, can kill bacteria buried 3 mm deep in the soft tissue of
the gums. The 1064 nm Nd:YAG laser is also effective with similar
penetration depth. Both lasers spare the healthy tissue with the
simulations showing minimal heating of the surrounding tissue.
Minimizing the thermal damage leads to faster healing, says Reinisch.
"The findings are important because it opens up the possibility of
tweaking the wavelength, power, and pulse duration to be the most
effective for killing bacteria," Reinisch says. "The doctors will look
at this and say, 'I see there is a possible benefit for my patients in
using the laser.'"
"The study reveals what's going on in the tissue, so I hope that
we're educating the medical professionals by demonstrating that you can
do a good job of killing bacteria with certain lasers," says co-author
David Harris, Ph.D., director of Bio-Medical Consultants, Inc., which
specializes in medical laser product development. "When you do this
treatment, you remove an infection and allow tissue to regenerate.
Getting rid of the infection means the tissue can heal without
The cost of dental lasers can range from $5,000 to over $100,000,
according to Reinisch, and health care professionals require extra
training to use them. These costs are passed on to the patient so
Reinisch notes there must be a definite benefit for the patient to
justify these costs.
Harris noted that the Academy of Laser Dentistry estimates that at
least 25% of US dental offices have dental laser capability for
periodontal treatment as outlined in the paper, along with a host of
other soft tissue surgical procedures and hard tissue procedures like
removal of dental decay.
Harris said the video simulations demonstrate what happens when lasers hit buried bacterial colonies.
"This is a great way to present to the doctor esoteric scientific
findings in a clinically meaningful format," he said. "The model is a
great tool for making predictions of what can happen in the tissue. Our
study confirms its use as a way to determine the most effective laser
parameters to use clinically."
In a first for the journal, the published results include video
depictions of the computer simulations. The journal readers can
actually see the soft tissue of the virtual gums and bacteria heat up
and cool down as the simulated laser is scanned over the tissue.
The study's methodology of simulating how laser light interacts with
tissue has implications beyond dentistry; physicians and surgeons use
lasers in various treatments, including vocal cord procedures and
dermatological treatments, including those for toenail fungus.
Guided by the results presented in this study, both Reinisch and
Harris expect that clinical trials will be designed to validate the
The study, entitled "Selective Photoantisepsis", is published in the October issue of Lasers in Surgery and Medicine