Laser therapy is not a foreign concept in most dental practices, as many dental practitioners include soft tissue surgical lasers in their arsenal of high-tech equipment. Low-level lasers are a subset of the laser family that elicit a cellular response from the cell, as opposed to a photothermal effect, resulting in improved healing, pain reduction and a reduction in inflammation. Low-level lasers frequently use wavelengths similar to surgical lasers; however, they use a significantly reduced power and a larger tip diameter.
TABLE 1.
As with surgical lasers, low-level laser devices require Health Canada approval (or FDA approval in the US) to be used in a clinical setting. This ensures that the applications are supported by extensive scientific research and assures patients that the therapy is safe.
Low-level lasers are generally sold as independent devices; however, Zolar Soft Tissue Dental Diode Laser have recently released a Health Canada approved device that houses two low level laser heads in their 810nm, 3Watt diode laser. Each head has settings to produce either a stimulatory or inhibitory effect, depending on the dosage used. This will be discussed in further detail below (Fig. 1).
FIGURE 1.
Mechanism of Action
Low-level laser therapy (LLLT) works at the cellular level to stimulate the production of cellular energy in the form of adenosine triphosphate, or ATP. ATP can be thought of as the gasoline of the cell–it provides the energy needed to help a cell function effectively and repair itself. Table 2 outlines some of the secondary and tertiary effects of Low-level laser therapy.
TABLE 2.
History of Laser Therapy
The use of light for healing and physical well-being is not a modern concept. For centuries, people have valued the healing nature of light and have historically used it in different forms of clinical therapies. Hospitals frequently took patients to their rooftops to help improve patient health. Light therapy has been studied and used for decades to combat winter depression (Seasonal Affective Disorder). One of the early pioneers of light therapy was Dr. Niels Finsen. He founded clinics that used sunlight and arc lamp light to successfully treat Lupus Vulgaris, Tuberculosis, and to prevent the scarring from smallpox, earning the Nobel Prize in medicine in 1903. When studies on light began in earnest in the 50s, many researchers were skeptical of the safety of light devices, often proposing that any wavelength in the electromagnetic spectrum might have negative effects (much like UV radiation) such as cancer. One such researcher, Dr. Endre Mester, set out to investigate whether this hypothesis was correct and found that the laser did NOT cause cancer or cellular damage in his animal models; it actually stimulated the healing of wounds and hair growth. This was one of the first documented demonstrations of the biostimulatory effects of light. Since then, thousands of in vitro and in vivo studies have been conducted on the use of laser therapy, many published in esteemed journals such as Nature, Pain and The Lancet. Further, laser therapy has been included in a number of evidence based clinical guidelines for neck pain, Achilles tendinitis and rotator cuff injuries.
Safety
It is only cells that are deficient in, or incapable of, producing optimal amounts of ATP that will be affected by LLLT. Once the optimal amount of ATP is being produced, our cells use the enzymes called ATPases to cease the ongoing production of cellular energy. As such, laser light will not negatively affect healthy cells and thus, there are no detrimental side effects to LLLT. This has been demonstrated repeatedly in the published literature and is a key factor in making it such an appealing treatment modality to an increasing number of healthcare professionals.
Using the Appropriate Dose
Treatment dose is probably the most important variable in laser treatment. Dose is measured in joules per square centimeter (J/cm2) and is a measure of the amount of energy that is conducted into the tissue. Clinicians should be aware of the optimal dose for each application to maximize the beneficial effects of laser therapy. Clinical effects of lasers, such as wound healing, pain relief or muscle relaxation, are all sensitive to different irradiances or doses. An example of using this principle would occur with the treatment of a dry socket. A dry socket occurs when then blood clot falls out and the bare bone is exposed, causing severe pain. At the first appointment, a high dose (16 to 64J/cm2) is used to mitigate the acute pain; when the patient returns for a dressing change, a low dose (4J/cm2) is applied to stimulate epithelial growth in the socket. This is best described by the Arndt Schultz principle: a weak stimulus increases the physiological processes and a strong stimulus abolishes physiological activity (Fig. 2).
FIGURE 2.
Clinical Effects of LLLT
LLLT has been used effectively in dentistry for more than four decades, though the magnitude of the positive clinical effects has just started to be documented in double blind placebo-controlled studies in the past decade. Clinically, LLLT can be used as an adjunct to surgical laser procedures as well as a treatment modality for a number of conditions and applications, some of which are noted below.
Post-Extraction
Effects of LLLT:
• Reduction of post-op pain
• Reduced need for analgesics
• Increased circulation for faster healing
• Reduced post-operative edema
• Reduced probability of dry socket as a result of improved epithelial healing (Fig. 3)
FIGURE 3.
Dry Socket
Effects of LLLT:
• Significant reduction in the acute and severe pain of the exposed socket nerves
• Subsequent appointments: stimulation of fibroblasts for the production of an epithelial layer in the socket
Soft Tissue Lesion (Herpes Lesions, Aphthous Ulcers and Denture Sores)
Effects of LLLT:
• Reduction in pain
• Prevention of lesion if caught in early stages
• Faster healing
• Decreased recurrence
Restorative and Crown Cementation
Effects of LLLT:
• ANALGESIA for small tooth preparations and crown cementations reducing the need for local anesthetic in these cases
• Reduction of post-op sensitivity
• Faster uptake and elimination of anesthesia
• Production of secondary dentin in deep restorative situations
Nausea and Gagging
Effects of LLLT:
• Application to the P6 acupuncture point decreases nausea and gagging (Figs. 4 & 5)
FIGURE 4.
FIGURE 5.
Endodontics (following root canals, pulpotomies, endodontic surgery)
Effects of LLLT:
• Reduction of post-op pain and inflammation
• Reduced need for post-op analgesics
Case Study: Diagnosis of irreversible pulpitis
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 radiograph was inconclusive. The low-level laser was applied to the apical region 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 that this was a case of irreversible pulpitis. The tooth was removed at the patient’s request and the pain disappeared completely.
Dentine Hypersensitivity
Effect of LLLT:
• Reduction in the conduction of c-fibres, which carry pulpal pain
• Stimulation of β-endorphins
• Reduced inflammation
• Stimulation of soft tissue healing
• This can accomplished used the Intraoral Handpiece at the apex and CEJ or with the Wand Handpiece, which can cover several teeth at both apex and CEJ.
• Using the Wand can be extremely valuable for hygienist to give analgesia to and arch in two to three minutes and in many prevent the need for the use of local anaesthetics. This application alone can be a practice builder (Figs. 6, 7 & 8) LLLT dentin hypersensitivity application
FIGURE 6.
FIGURE 7.
FIGURE 8.
Orthodontics
Effect of LLLT:
• Reduces intensity of pain
• Increases speed of tooth movement because of stimulation of osteoblasts
Implants
Effects of LLLT:
• Reduction of pain after surgery
• Faster integration of implant
Case Study: Implants
A patient presented with a cracked tooth that had abscessed over time. The patient was referred to an oral surgeon, who sectioned the tooth and removed some bone. The low-level 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. The patient experienced no pain, despite refusing both prescription and over-the-counter medications. Over the following three weeks, the laser was applied twice weekly around the extraction site. At three months, the patient returned for implant placement, again without pain medication or any discomfort. At the time of surgery, the surgeon commented on the quality of bone at site. Photobiomodulation was applied during both procedures to the buccal and lingual surface. (Author’s note: I can attest to the accuracy of this case study, as I was the patient.)
Sinusitis
Effects of LLLT:
• The laser can help to reduce the inflammation and congestion within the sinuses, which significantly reduces pain
• The lymphatic system is also treated (Fig. 9): Treatment of sinus problems
FIGURE 9.
Nerve Regeneration
Effect of LLLT:
• Return of sensation after traumatic damage or severing of a nerve
Treatment Tip:
• Apply twice weekly
• May take up to 20 sessions
• When the patient feels tingling or burning of nerve, stop laser treatment and monitor progress
Preventing Trismus after Long Appointments
• Apply superiorly, cover the top of the masseter being sure it goes over the TM Joint (this ensures you are treating the joint and the lateral pterygoid)
• Treat the rest of masseter until you reach the lower border
TMJ Protocols
Submandibular lymphatics (Fig. 10): Submandibular Lymph Nodes
Temporomandibular Joint (Fig. 11): Temporomandibular Joint Application
FIGURE 10.
FIGURE 11.
Styloid Process
The joint capsule is being treated in the superior position and in all three positions; the styloid muscles and ligaments, as well as the posterior digastric muscle, are being treated (Fig. 12): Application to Styloid Process Temporalis–Anterior and Posterior (Fig. 13): Application to Temporalis Muscle Masseter – Superior and Inferior (Fig. 14): Application to Masseter Muscles Sternocleidomastoid – Treat at sternal clavicular junction and anterior to mastoid area (see diagram C)
FIGURE 12.
FIGURE 13.
FIGURE 14.
If there are any trigger points in the body of the muscle, these should be treated, carefully angling the beam away from the thyroid gland (Figs. 15 & 16): Application to the Sternocleidomastoid Muscle
FIGURE 15.
FIGURE 16.
Other Applications
The applications of low-level laser therapy extend well beyond the dental chair. Groundbreaking research on wound healing, stroke, heart disease, neurological conditions and cancer are showing extraordinary results that could have a remarkably positive impact on medicine in the future.
Low-level laser therapy is common in many other healthcare practices, with chiropractors, massage therapists, tissue injuries utilizing these devices as an adjunct to their current regime or as a prime treatment modality to ease the strain of these very physical endeavours. Clinical research on muscle repair and fatigue is of great interest to many athletes and their trainers; extensive research to enhance the athletic performance is increasing.
Conclusion
Healthcare practitioners have few options for pain relief, reduction of inflammation and swelling and wound healing stimulation that don’t involve pharmaceuticals with many detrimental side effects. Low-level laser therapy is non-invasive and non-toxic, making it an attractive alternative to pharmaceuticals. Dental practitioners are often unaware of how to utilize their existing surgical laser devices to offer the amazing effects of low-level laser therapy.OH