Abstract
In my acquisition of knowledge, I have had several paradigm shifts that have dramatically changed how I treat patients and practice dentistry.
The first was having a thorough understanding of the mechanisms of LLLT. By understanding these mechanisms, any condition or pathology can be treated optimally and efficiently.
The second was achieving a better understanding of the effect of light on the lymphatic and immune systems. This has led to a totally different and much more successful treatment sequence. The combination of the lymphatic and circulatory systems makes almost every area of the body accessible to light, directly or indirectly. This paradigm shift has been instrumental in the improved successes seen in a number of clinical cases.
Finally, an understanding the principles of biostimulation and bioinhibition, or the biphasic response, has allowed for tailoring of treatment dose based on the physiological response required by the cell. 3 Many associate inhibition with negative connotations, when in fact it can be beneficial, depending upon the pathology being treated. The utilization of the principles of the biphasic response will be demonstrated subsequently.
Among the benefits of photobiomodulation in dentistry are:
• My use of analgesics and pharmaceutical pain management has decreased by ∼90%.
• The reduction in postoperative pain without the use of medications has dramatically changed the way patients view their dental procedures, and makes dentistry a more pleasant experience. Whereas dentistry has always been closely associated with pain and has even been feared, its reputation is now changing dramatically, especially in the younger generations that experience this type of “pain-free dentistry.”
• In cases where there is postoperative pain from a procedure, it can be managed and eliminated quickly and effectively.
• The number of root canals required has been reduced by ∼50%, primarily because the significant inflammation caused by deep cavities that leads to a root canal treatment can be modulated by laser irradiation. Managing the inflammation at the cavity stage decreases the probability that it will cause pulpal death and ultimately necessitate a root canal.
• In a number of conditions, the results seen with laser therapy have superseded those that are seen with traditional methods. Some examples of this include the treatment of facial pain, nerve regeneration, and the treatment of postoperative pain.
• Laser therapy is noninvasive and with no reported cases of it causing harm, treatments can be performed by the trained members of a dental auxiliary staff and easily integrated into a practice.
Dental Procedures Using Photobiomodulation
Dental surgery
Following extractions as well as bone surgery, LLLT can be used to effectively eliminate postoperative pain, stimulate lymphatic flow, which effectively reduces edema, modulate inflammation, and stimulate osteoblasts. 4,5 Pain is the primary concern immediately following dental surgery; therefore, a high dose (8–16 J/cm2) is used immediately and preferably directly into the socket. In cases in which a soft tissue flap is involved in the procedure, a low dose (2–4 J/cm2) is applied after suturing to stimulate the fibroblasts and obtain faster wound healing. 6
Restorative procedures
Laser therapy has been shown to reduce the conduction of nerve fibers. C fibers, which carry pain sensations from the dental pulp, have a very thin myelin sheath and respond to light very dramatically. 7 Clinically, laser irradiation applied at a higher dose (8–16 J/cm2) can provide significant pulpal analgesia, which allows for a number of dental procedures to be performed without the need for “freezing.” Laser therapy used in conjunction with appropriate patient management techniques is very useful for pedodontic procedures, which eliminate the issues that normally come with providing primary tooth restorations (fear, misbehavior, biting of the lips and tongue while area is frozen). Both red and infrared light have shown success in this area, and the use of different doses has allowed me to treat teeth with larger pulps without local anesthetic.
Endodontic procedures
LLLT can assist with endodontic procedures by reducing postoperative pain and swelling, eliminating the need for analgesics, and reducing pulp hyperemia. Following root canal treatment, a high dose (8–16 J/cm2) is applied at the apex of each root to reduce postoperative pain and modulate the inflammatory response.
Soft tissue lesions
Using laser therapy for soft tissue lesions (herpes simplex, aphthous ulcers, and, most dramatically, oral mucositis) can reduce pain and speed tissue healing. The lymphatic system is treated first, followed by the direct application to the lesion in a noncontact mode. Pain relief is almost instantaneous, and healing is dramatically improved. A study by Munoz Sanchez et al. recently showed the laser irradiation can, in some cases, prevent lesion eruption when applied at the prodromal (tingling) stage as well a causing a decrease the recurrence of lesion outbreaks. 8
A number of studies have demonstrated the effectiveness of laser irradiation on both the prevention and treatment of oral mucositis. This can be a very debilitating condition for patients undergoing chemotherapy and radiation treatments, and medicine has few options that can successfully manage the problem. The successes demonstrated by Whelan et al., 9 as well as in numerous other studies, strongly indicate that laser therapy should be included in the standard of care for all patients undergoing chemotherapy or radiation treatment.
Dental implants
Photobiomodulation has proven to be an invaluable tool in the placement of implants by both improving the quality of the bone and giving faster implant integration. 10 A number of studies have demonstrated the effectiveness of laser irradiation on the stimulation of osteoblasts, which is useful both in implants and bone grafting procedures associated with implants. 11 Clinically, a high dose is used at the time of implant placement for pain and inflammation control. Subsequent visits, every 2–3 days for 2 weeks, uses a lower dose (2–4 J/cm2) for stimulation of osteoblasts. 12
Orthodontics
In addition to reducing pain intensity after orthodontic adjustments, laser therapy can also increase the velocity of tooth movement through the stimulation of the osteoclasts and osteoblasts. 13,14 A 2004 study by Cruz et al. demonstrated that the canines on the laser-treated side retracted 34% faster than those on the control side. 15
Facial pain
Photobiomodulation has been shown to have a significant effect on a number of musculoskeletal conditions, including craniofacial pain and osteoarthritis of the jaw. This area of treatment is a very large component of my practice, largely on a referral basis from other practitioners. Prior to using laser therapy in temporomandibular joint disorder (TMJ) cases, I primarily used muscle relaxants, anti-inflammatories and anti-depressants, all of which had numerous negative side effects. Currently, I have almost totally eliminated the use of these medications and the results are superior.
Acute cases, such as facial pain after long dental appointments, can be treated quickly, often only requiring one to three treatments. However, many patients have chronic craniofacial pain and will require multiple sessions over a longer period of time. The greatest success seems to be treating the affected joint/area for 2–3 weeks and then halting treatment before the patient is reassessed to determine the level of improvement. The goal of the break in treatment is to let the body continue to heal itself. Dostalova et al. demonstrated that laser irradiation showed positive results in the treatment of TMJ. After laser irradiation, pain on the visual analogue scale (VAS) reduced from 27.5 to 4.16 and the mouth opening improved from 34 to 42 mm. 16
Neuropathic pain and trigeminal neuralgia continue to be debilitating for patients and frustrating for the healthcare practitioners who are trying to treat it. The pharmaceuticals prescribed as treatments for these conditions frequently bring with them as many problems as they are trying to fix. With a uniquely tailored treatment course with each case, I have repeatedly seen laser therapy to be both more effective and substantially safer than any medications I have used in the past.
Conclusions
Photobiomodulation continues to be an incredible asset to a dental practice. It is no longer necessary for patients to fear a visit to the dentist, and gone are the days when patients would leave the office wincing in pain. With laser therapy as a prominent tool in practice, clinicians will be able to provide a higher level of care, with reduced stress for both the patient and the doctor. It is my profound hope to see photobiomodulation become one of the standards of care in dentistry.