Low-power
lasers reduce pain, promote healing
By Kathy Kincade, Editor in Chief
August 1,
2008 -- Lasers are often portrayed as powerful beams of light that can cut --
even destroy -- missiles, metal, bone, tissue, and, in some sci-fi movies,
aliens from outer space.
Not all
lasers are created equal, however. Most laser devices used in dentistry operate
at power levels around 2-20 watts -- strong enough to cut and cauterize soft
tissue and "drill" hard tissue, yet gentle enough to avoid destroying
the tooth, adjacent tissue, or underlying pulp.
The science of LLLT Generally speaking, low-level laser therapy works by
applying approximately 200 mW of visible or
infrared light for several seconds to the target tissue. Light penetrates
through the tissue and is absorbed by proteins in the cells without damaging
them. In fact, the laser energy has a stimulating chain reaction within the
cells (thus the moniker "biostimulation").
Singlet oxygen (free radicals) are generated, stimulating the production of
adenosine triphosphate (ATP, which is responsible
for transporting chemical energy within cells) in the mitochondria. This in
turn produces a number of physiological affects. According to the World
Association of Laser Therapy (WALT), these affects include: ·
Ion
channel normalization (pain reduction) ·
Increased
beta endorphins (decreased pain response) ·
Increased
nitric oxide production ·
Decrease
in the amount of C-reactive protein neopterin ·
Acceleration
of leukocytic activity ·
Vasodilation stimulation-enhanced lymphocyte response ·
Increased
collagen synthesis in fibroblasts ·
Increased
formation of capillaries by the release of growth factors ·
Transformation
of fibroblasts to myofibroblasts (allows for
increased muscle growth and strength) ·
Stimulation
of osteoblasts (builds bone) |
But an
entirely separate class of lasers is intended not to cut or vaporize tissue but
to stimulate underlying cellular changes. For years, research has shown that
low-level laser therapy (LLLT, also known as phototherapy or biostimulation) can reduce pain and inflammation,
accelerate wound healing, and bring relief to patients suffering from chronic
conditions such as arthritis and carpal tunnel syndrome.
The
concept of using low levels of light-based energy for therapeutic purposes was
first proposed by Albert Einstein in 1917. It wasn't until the 1960s that a
Hungarian surgeon named Endre Mester
first reported on experiments using laser energy to treat infections and
inflammations in rats. This work led to the development of LLLT as an
adjunctive therapy for pain relief and wound healing, with more than 2,500
published studies supporting its use in a spectrum of medical applications.
The first
commercial LLLT product was developed in 1962, and today there are a number of
international suppliers, including Irradia (
In fact,
while the concept of LLLT has been widely accepted by the international medical
community for pain relief and wound healing for more than 30 years, it has yet
to have the same impact in the U.S. According to manufacturers of LLLT devices,
the technology has been well-adopted by physical therapists, veterinarians, and
professional athletes in the
"In
Europe, they are so far ahead of us in biostimulation,"
said Chris Walinski, D.D.S., a private practice dentist
in
LLLT in
dentistry
Similarly,
LLLT has a long history in dentistry -- outside of the
For
example, a Japanese study on the efficacy of LLLT for treating dentine
hypersensitivity found that diode-laser LLLT was effective in reducing dentine
hypersensitivity in all 25 study participants (Journal of Clinical Laser
Medicine and Surgery, October 2003, Vol. 21:5, pp. 291-296). A more recent
study by Brazilian researchers found that diode-laser LLLT accelerates the
recovery of dental structures involved in cavity preparation at the predentine region (Archives
of Oral Biology, September 2007, Vol. 52:9, pp. 899-903). Another
Brazilian study indicated that low-level laser therapy can accelerate tooth
movement during orthodontic treatment and reduce pain, leading to greater
patient satisfaction and compliance (Lasers in Medical
Science, January 2008, Vol. 23:1, pp. 27-33).
On the
commercial side, some companies -- including MedX, HomeHealthCare, and Luminax --
are beginning to offer dental-specific LLLT products to the
|
The Oralase LLLT device by MedX Health. |
"While
LLLT is on the verge of FDA clearance [for dentistry], it has been used for
over 25 years in Europe and Asia and for the last five to six years in
More than
30 different dental indications have been reported in the literature, according
to MedX. Common applications include treating
abscesses, oral herpes, denture sores, and hematomas;
substituting for anesthesia during crown preparation and pediatric procedures;
decreasing dentine hypersensitivity; accelerating nerve regeneration;
decreasing pain and accelerating movement of teeth during orthodontic
procedures; treating joint and jaw dysfunction such as TMJ and arthritis; speeding
the integration of dental implants; and reducing pain and edema following endodontic, restorative, and periodontal surgeries.
Grace Sun,
D.D.S., a private practice dentist in
"My
patients love it," she said. "They think I am a wonderful
doctor."
Gerry
Ross, D.D.S., of
"I
use it on everybody," he said. "To me, it is the standard of
care."
Dr. Walinski first became a LLLT "convert" after
twisting his knee while traveling in
"He
treated me for about two minutes and, at first, I didn't feel anything,"
he said. "But about two minutes later, I started feeling this pop, pop,
pop in my thigh and I said, 'What is that?' And he said, 'That's your lymphatics opening up.' And I walked out of there with less
swelling and pain."
Today, Dr.
Walinksi has at least 10 different lasers in his
practice, including a 10-watt diode laser intended for tooth bleaching that he
also uses for LLLT. He has developed specific protocols in the range of 1-2
watts for dental treatments such as for TMJ, and he uses the laser after every
surgical procedure as a pain management tool.
"I am
definitely a believer, but it took a personal experience to make that
happen," he said.
Seeing is believing
At this
point, it is still unclear what role LLLT will play for the majority of
“My patients love it. They think I am a wonderful doctor.”
— Grace Sun, D.D.S.,
"I
haven't used LLLT on my patients and only know basic information about
it," Dr. Coluzzi said. He also pointed out that
the phrase "low-power" can be misleading since a lot of dental
surgery is performed at 1 or 2 watts, which is low power. "The current
phrase for LLLT is being replaced by 'photobiomodulation,'
which is more descriptive of the mechanisms and results," he said.
Dr. Ross
says education is, in fact, the key to making more people in the dental
community aware of the benefits of LLLT. But even that could be a challenge,
noted Craig Gimbel, D.D.S., former president of the
"You
will always have skeptical people who will criticize technology because they
are not open to learning about it and the science behind it," he said.
"When it comes to LLLT, although there has been so much research done on
it, there has been little published about it. Those dentists who are educated
about lasers want to know more about low-level lasers."
For the
time being, personal experience and word of mouth may be the best educational
tools.
"Everyone
claims there aren't enough studies, but there are more studies on this than
there are studies of higher-power lasers," Dr. Ross said. "We need to
get it into the mainstream media. But eventually everyone in dentistry will be
using LLLT."
For
more information about LLLT and how it can and should be used, go to www.walt.nu, www.laser.nu, www.laserdentistry.org, or www.laserlightcanada.com.