LASER Advancement in Dentistry

Laser dentistry is commonly thought of as a substitution of modern equipment for the dreaded drill. But low level laser therapy (LLLT) takes dentistry into new realms, enabling previously impossible procedures and improving upon scalpel and electrocautery operations.

Advancements in dentistry

Taking the global biological effect into consideration, it is logical that LLLT can influence many conditions appearing in the dental area. Following are a few important possibilities.

Laser acupuncture. While few dentists are trained in acupuncture, they could use some safe points–for instance, P6 on the wrist, useful to reducing gagging–for the safety and comfort of patients. Functional magnetic resonance imaging (fMRI) studies have confirmed that lasers and needles actually have similar, although not identical effects. Bone regeneration. Several in vitro and animal studies indicate that LLLT has a positive effect on bone regeneration. This has consequences for both periodontology and implantology. Repeated irradiation can activate osteoblasts and also stimulate the integration of implants. Optimally, the irradiation should start during the surgery and continue during the first two weeks of recovery.

Dental caries. A cavity or crown preparation is a burden for dental pulp, the part in the center of a tooth made up of living connective tissue and odontoblast cells. LLLT applied after preparation and before cementation can reduce postoperative problems and potential endodontic work.

Dentinal hypersensitivity. Several studies have been published regarding the effect of laser phototherapy for dentinal hypersensitivity. While stronger lasers have the ability to seal dentinal canals, the therapeutic lasers do not have any such effect–but they will influence the odontoblasts and the pulp.

The therapeutic effect of the "surgical" lasers has generally not been realized. All used wavelengths apparently have an effect, given the proper dosage. Irradiation has been directed towards the exposed dental necks and sometimes also over the projection of the apices. For this latter approach, infrared is needed, except for the upper incisives.

Herpes Simplex (HSV1). While there are few clinical studies available to prove it, LLLT is reported to be fast and very effective for treatment of mouth sores .When HSV1 is treated in the prodromal (initial) stage, the attack will likely subside: pain relief is immediate and the intermediate period between the attacks is prolonged. The effect is supposed to be similar to that provided by the prescription medication Acyclovir, but without side effects. Interestingly, patients with recurrent herpes attacks can be treated even in the silent periods.

Mucositis. An inevitable effect of radiation and, in many cases, chemotherapy, mucositis is documented to be treated effectively by LLLT for pain reduction and incidence. The HeNe laser was first documented, but red and infrared laser diodes appear to be useful as well. Best results are obtained when LLLT is initiated before the radiation/chemotherapy since LLLT has a radioprotective effect. Intraoral irradiation is rather time-consuming and extra oral application via red LED arrays has been proven effective. Future research may look into the same concept for less staff-intensive laser applications.

Nerve recovery. There are many papers about the effect of LLLT on the function and recovery of peripheral nerves. This therapeutic modality seems very attractive in oral surgery, where injuries of nerves such as the inferior alveolar nerve and the facial nerve are likely to occur in some types of surgery. LLLT can be used as an immediate protective treatment. However, it is also reported that even long-standing aberrations can be influenced.

Orofacial pain. Especially in dentistry, where pain is one of the most feared expectations, pain reduction is a highly desired effect of LLLT. Achieving it requires higher doses than general stimulation, though–so pain reduction and tissue stimulation cannot be achieved at the same time. LLLT can make pain subside gradually by reducing the period of inflammation. However, the dose window for this outcome is lower than that for immediate pain reduction. LLLT stimulates opioid precursors and causes transient axonal vesicles, which reduce neural transmission (see Fig. 5). Trigeminal neuralgia (inflammation of the trigeminal nerve) and postherpetic neuralgia (a complication of shingles) are two indications suitable for LLLT. This therapy is not likely to cure a trigeminal neuralgia, but it will facilitate a reduction of intake of the prescription drug Carbamazepine.

Orthodontics. There is some documentation for the use of LLLT to reduce the pain experienced during tooth movements and also to increase the velocity of tooth movement.Low dosage seems to accelerate the speed of movement, whereas higher dosage appears to slow movement. In the latter case, this could possibly be used for stabilization of a finished orthodontic therapy.

Periodontics. While high-power lasers have received much attention for their ability to reduce pocket microbes and to remove the pocket epithelial lining, therapeutic lasers have received less attention. However, a number of studies suggest that LLLT can reduce pocket inflammation and be useful in combination with traditional methods. Irradiation reduces post-operative pain and discomfort, but several irradiations are needed to produce tissue regeneration. LLLT in itself has no germicidal effect, but if used in combination with a suitable dye, a photodynamic effect can be achieved.

Temporomandibular joint disorders (TMDs). TMDs can be either arthrogenic, myogenic or both in combination. The effect of LLLT on arthritic conditions is well investigated and there is moderate evidence of an effect on myogenic pain and trismus. For arthrogenic conditions, low doses are required, whereas myogenic conditions require infrared laser and high dosage. Pain- and spasm-relieving effects are fast, and trismus–the inability to fully open one's mouth–can be resolved or improved within minutes.⁶² Since the occipital and neck muscles are frequently involved in TMD, the laser will add benefits for the dentist and patient.

Wound healing. The literature contains a multitude of studies on the wound-healing aspect of LLLT. The early studies were performed on healthy test animals and showed moderate results. Modern studies using a diabetic-rat model have proven more successful. The best clinical effects are also seen in long-standing wounds where traditional therapies have failed.^{69, 70} LLLT is, therefore, an excellent adjunct treatment modality in diabetic patients.

Conclusion-

LASER is effective in improving prognosis, painless and bloodless treatment and have wide use in field of dentistry.

 (By Dr. Ajay pandey :BDS-Army Dental college, MBA, General management-IIM-L)