December 1, 2009
by Gerry Ross, DDS and Alana Ross, BScH
Imagine a tool that could reduce pain, improve wound healing, relieve muscle tension and regenerate nerves without the use of pharmaceuticals and the associated side effects. Although it may sound like magic, it’s actually a therapeutic technology that has been used clinically for decades: low level laser therapy (LLLT).
Light therapy has been used for years as a treatment modality for various pathological conditions. Early in the 20th century, many physicians recognized the benefit of using light to improve the health of hospital patients and would frequently take their patients to the roof to sit in the sunlight. To this day, many people suffering from Seasonal Affective Disorder (SAD) utilize light therapy during the winter months to combat depression that can occur when sunlight is at a minimum.
One of the first people to demonstrate the use of light as a therapeutic tool was Dr. Endre Mester in 1966. During an experiment investigating whether a low level laser could cause cancer, he shaved the bellies of two groups of rats and irradiated the skin. He was surprised to see that laser irradiation didn’t cause any cancerous cells and that the hair on the stomachs of the laser group grew back significantly faster. The following year, he treated wounds on rats and saw startling results in the accelerated healing of the wounds.1 These were some of the first indications of the benefits of photobiomodulation and inspired hundreds of research groups to investigate the effects of laser therapy both in the lab and clinic.
Low level laser therapy (LLLT), also referred to as phototherapy or photobiomodulation, uses light energy from lasers or light emitting diodes to elicit cellular and biological responses in the body. Light photons work on various cell processes to stimulate the release of cellular energy, which can be used to facilitate the restoration of normal cell morphology and function.2
This additional energy is also available to power many secondary side effects, which are noted in Table 1.
There have been some extraordinary advancements in the clinical applications of laser therapy in many healthcare fields. Conditions such as chronic back pain, tendon strains, cold sores, burns and strokes are treated regularly in many clinics and the use of LLLT and photodynamic therapy as a treatment for tumours are at the forefront of clinical research. One of the biggest breakthroughs in the medical field has been the treatment of diabetic ulcers and chronic wounds. Diabetic ulcers are very slow to heal and often results in the amputation of digits and limbs. Laser irradiation of the nerve ganglia and around the wound can substantially speed the healing of the ulcers and, often, eliminates the need for an amputation.3
One of the first approvals for LLLT was for the treatment of repetitive strain injury, also referred to as Carpal Tunnel Syndrome (CTS). This condition is incredibly prevalent in Western society as a result of the large amount of time people spend at computers or working in positions that require repetitive movements. CTS can also be a big problem in dental offices due to the position dentists, hygienists, assistants and receptionists work in throughout the day. CTS presents as extreme pain and tingling in the arm, wrist and hand, often requiring people to take large amounts of anti-inflammatory and pain medications. In more severe situations, surgery is required. Laser therapy is very effective in the treatment of CTS and can alleviate the pain and tingling in the arms, hands, and fingers. A study investigating the effect of laser therapy in the treatment of CTS found that laser irradiation completely resolved symptoms in 77% of patients and the nocturnal complaints in 93% of patients.4
When most dentists hear the word laser, they often think of a hard or soft tissue laser that is used to cut enamel or soft tissue. Low Level Lasers are another subset of laser therapy that is a virtually untapped commodity in dentistry, yet which would be a huge asset to a dental practice and its patients. LLLT can benefit almost every aspect of a dental practice, regardless of whether it is a general dental practice or a dental specialist. Stimulation of endorphins; reduction in the conduction of nerve fibres that carry pulpal pain (c-fibres); stimulation of fibroblasts, osteoblasts and odontoblasts; and increased circulation and lymphatic drainage can all aid in improving clinical outcomes and decrease the pain felt by a patient after dental appointments.5
Some of the most frequently used clinical applications in dentistry include:
Laser irradiation will significantly decrease pain, swelling, bruising and inflammation after an extraction thus requiring a decreased (or eliminated) need for post-operative analgesics. The speed of healing of the extraction site will also be increased and there will be a reduced likelihood of a dry socket (although in cases where a dry socket does occur, LLLT will dramatically decrease the pain and stimulate the covering of the exposed bone through the stimulation of fibroblasts).
LLLT is being used by many dentists and pedodontists for analgesia of primary tooth restorations. Application at the apex decreases the conduction of nerve impulses from the pulp and stimulates the release of endorphins, both which contribute to a decreased pain sensation (analgesia).6 Though this technique works best on primary teeth (Figure 2), laser irradiation will allow for comfortable air abrasion treatments and crown & bridge cementations. Without the effect of anesthetic, it is easier to accomplish a proper bite adjustment.
Many patients have a sensitive gag reflex making dental work very stressful for both the patient and dentist. Application of the laser to the P6 acupuncture point of the wrist will decrease the gagging and nausea sensations many patients feel during dental treatments, impressions and x-rays.7 The P6 acupuncture point is one of a triad of points that calms your parasympathetic nervous system (Figure 3). Application of these points is also effective for patients who are anxious and nervous.
In any case of a dental infection, the laser can be applied to the submandibular lymph nodes to increase the lymphatic flow of the infected area, reduce the inflammatory cells and bring neutrophils to the site of infection for faster healing (Figure 4).8 Laser therapy will not preclude the use of antibiotics in most cases but will help to potentiate the uptake of the antibiotic into the blood stream.
Laser irradiation during the preparation and placement of implants will decrease the pain and inflammation of the surgical procedure and improve the integration of the implant into the bone. Many studies investigating the effect of LLLT during implant placement have demonstrated an improved bone formation around the implant with a substantial decrease in post-operative pain.9
In addition to reducing the pain felt during orthodontic treatments, laser irradiation has also been shown to increase the velocity of tooth movement. A recent study demonstrated that over 60 days, the canines on the laser treated side moved 34% more than the control.10 It has been postulated that the increased speed of tooth movement is a result of the stimulation of the osteoblast/osteoclast turnover.
Laser therapy can be used very effectively for facial pain treatment, either acute or chronic. A major complaint a lot of patients have after long dental appointments is facial pain and muscle tension.11 Application of the laser to the masseter muscle after the appointment will reduce or eliminate the muscle trismus and joint pain. In chronic TMJ cases, laser therapy can be used in conjunction with other therapeutic tools to reduce the pain and muscle tension, while stimulating healing within the joint.
LLLT can assist with pain and inflammation after endodontic procedures and surgery, treat pulp hyperemia, help diagnose irreversible pulpitis and reduce the need to post-operative analgesics.Further, laser irradiation is very effective in treating dentine hypersensitivity. A recent study demonstrated that combining laser therapy with a chemical agent produced an average success rate of more than 85%.12
Soft tissue lesions, such as herpes lesions, denture sores, angular chelitis and lichen planus, respond very well to LLLT. Research has indicated that LLLT can prevent cold sores from erupting if treated in the prodromal stage (when the tingling starts) and speed the healing in cases where the sore has erupted.
Clinically, light therapy can be used with ease in a dental office. Because laser therapy is non-invasive and has no significant side effects, the treatments can frequently be done by the auxiliary staff and easily integrated into the practice.
Light therapy uses the body’s own natural resources to provide pain relief, muscle relaxation, wound healing and nerve. Low Level Laser Therapy offers a dentist the opportunity to better manage treatments that are often deemed painful by patients while enhancing their practice with improved clinical treatments and patient satisfaction.
One of the most interesting and useful aspects of LLLT is the safety. Lasers only elicit responses from cells that can utilize the energy produced, thus will have no negative effect on healthy cells.13 In the hundreds of studies done on laser therapy, no clinical side effects have been reported. This puts lasers in the public domain and with very basic training, can be used by the whole dental staff.
A huge benefit of Low Level Laser Therapy is that patients see their dental practitioner doing something extra to reduce the pain or discomfort that may have been caused during the appointment. The very nature of what dentists do causes pain and inflammation. LLLT requires a paradigm shift; instead of using drugs to treat the pain after it has started, a dentist now has the opportunity to treat the pain immediately in the dental office. In an aging population that is becoming wary of the over-prescription of pharmaceuticals which often carry negative and harmful side effects, laser therapy is an effective alternate or adjunctive tool to achieve improved clinical effects. It is a benefit to the patient and dentist to investigate Low Level Laser Therapy, an untapped resource in the dental industry.
Dr. Ross is the president of Laser Light Canada and works with multiple phototherapy equipment manufacturers.
Oral Health welcomes this original article.
References available upon request.
A 58 year old female developed a diabetic complication on her toe that would not heal even with 3 months of conventional wound care. The centre of the lesion was necrotic and the arterial circulation of the forefoot was mpaired. Her doctor recommended the toe be amputated but she decided to visit Meditech Rehabilitation Clinic, a leader in wound care. After completion of laser therapy, the ulcer had healed, arterial circulation restored and an amputation was avoided.
A patient presented with a cracked tooth that had abscessed over time. The patient was sent to an oral surgeon, who sectioned the tooth and removed some bone. The laser was applied immediately after extraction, both in the socket and along the suture line. The oral surgeon offered to prescribe Percocet for pain, but the patient declined and experienced no pain. Over the next 3 weeks, the laser was applied 2 times per week around the extraction site. 3 months later, the patient returned to have an implant placed. At the time of surgery, the surgeon commented on the quality of bone at site. LLLT was applied both after the site was prepared and after the implant was placed, to the buccal and lingual surface. The patient experienced no post-operative pain and took no pain medications.
A 42 year old patient presented with a tooth ache in the upper right quadrant. She was unable to accurately identify which tooth was causing the pain and the x-ray didn’t show anything of significance. The laser was applied to the apex of each tooth until the patient felt a pain response, indicating the affected tooth. The laser was taken away for one minute to allow the inflammatory chemicals to drain and then reapplied to the affected tooth. Patient felt immediate pain, indicating it was a case of irreversible pulpitis. The tooth was removed at the patients request and pain disappeared completely.
A 36 year old patient presented with erosive lichen planus. The patient was in excruciating pain and could not eat or drink without extreme discomfort. The laser was applied along the erosion sites inside the mouth 2 times, a day apart. During the second treatment, the erosion sites were significantly smaller and the patient noted that the pain had decreased enough that he could eat soft foods comfortably. By the end of the first week, the patient was asymptomatic.
A Toronto oral surgeon studied the effect of LLLT on the pain and swelling reduction after wisdom tooth extraction by lasing one side of the mouth and using the contralateral side as a control. The results were so significant that he ended the study after 3 weeks, concluding it would be unethical to continue the study when the laser had such a positive effect.
A 20 month child presented with baby bottle caries in the upper anteriors that needed to be restored. Normally, this patient would have been sent to a paedodontist to have the appointment done under sedation or general anaesthetic. However, in this case, the laser was applied to the apex and the restoration was completed with no anaesthesia. Laser application was well received by the patient and the mother was thrilled that the appointment was so easy.
• Increased lymphatic flow resulting in decreased edema (swelling)
• Stimulation of b-endorphins, which are the bodies natural pain killers
• Reduction in the conduction of c-fibres, which carry pulpal pain
• Reduction in the release of Histamine, Bradykinins, and Acetylcholine, which reduces the pain associated with inflammation
• Stimulation of Osteoblasts, Odontoblasts and Fibroblasts, which stimulate the growth of bone, dentin an soft tissue, respectively
• Increased activity of Neutrophils and Macrophages
• Stimulation of Nerve Regeneration
Surgical Laser Low Level Laser
Power 1-5W 10-500 mW
Diameter of Tip 300-400 m 1 cm
Heat Generated Yes >0.1 C
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