Low-level laser therapy prevents medication-related osteonecrosis of the jaw-like lesions via IL-1RA-mediated primary gingival wound healing.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) is a serious debilitating disease caused by anti-resorption and anti-angiogenesis drugs, significantly affecting patients' quality of life. Recent studies suggested that primary gingival wound healing may effectively prevent the development of MRONJ. This study aimed to evaluate the effects of low-level light therapy (LLLT) on promoting gingival wound healing in extraction sockets of MRONJ-like mice and preventing the occurrence of MRONJ. Furthermore, we explored underlying mechanisms. METHODS: Mice were randomly divided into the Ctrl, Zol, and Zol + LLLT groups. Administration of zoledronate and tooth extraction of bilateral maxillary second molars were used to build the MRONJ model, and LLLT was locally administered into the tooth sockets to examine the effect of LLLT. Next, to explore the function of IL-1RA, we performed LLLT with interleukin-1 receptor antagonist (IL-1RA) neutralizing antibody (named Zol + LLLT + IL-1RA NAb group) or negative control antibodies for tooth extraction in subsequent rescue animal experiments. Stereoscope observations, micro-computed tomography, and histological examination were conducted to evaluate gingival wound healing and bone regeneration in tooth sockets. The effects of LLLT on the migration capacities of zoledronate-treated epithelial cells were assessed in vitro. RESULTS: LLLT promoted primary gingival wound healing without exposed necrotic bone. Micro-computed tomography results showed higher bone volume and mineral density of the tooth sockets after LLLT. Histology analysis showed complete gingival coverage, obvious bone regeneration, and reduced soft tissue inflammation, with down-regulated pro-inflammation cytokines, like interleukin-1 beta (IL-1ß) and tumor necrosis factor-α (TNF-α), and up-regulated IL-1RA expression in the gingival tissue in the LLLT group. The rescue assay further showed that the effects of LLLT promoting gingival wound healing and preventing MRONJ might be partially abolished by IL-1RA neutralizing antibodies. In vitro studies demonstrated that LLLT accelerated zoledronate-treated epithelial cell migration. CONCLUSIONS: LLLT might promote primary gingival wound healing and contribute to subsequent bone regeneration of the tooth extractions in MRONJ-like lesions via IL-1RA-mediated pro-inflammation signaling suppression.

Comparison of Nd:YAG Laser and Surgical Stripping for Treatment of Gingival Hyperpigmentation: A Clinical Trial.

OBJECTIVE: The objective of this study is to evaluate and compare surgical stripping and neodymium-doped: yttrium, aluminum garnet (Nd:YAG) laser techniques for gingival depigmentation and to evaluate their effect on repigmentation. BACKGROUND DATA: Gingival depigmentation is often associated with repigmentation. Recurrence of pigmentation differs according to different treatment modalities. MATERIALS AND METHODS: In this study, 40 maxillary sites from 20 patients presenting bilateral melanin gingival hyperpigmentation were selected. Contralateral quadrants in the maxilla were randomly assigned to receive Nd:YAG laser at 3 W, 30 mJ per pulse, with contact mode, and with a handpiece with a 300 µm diameter optic fiber and surgical stripping. Plaque index, Dummett Oral Pigmentation Index (DOPI), Hedin melanin index, size of pigmented area, time interval and extent of repigmentation, time taken for each of the procedures, assessment of pain, intraoperative bleeding index, and patient preference were compared from baseline to 6 months. RESULTS: Comparison between Nd:YAG laser and surgical stripping group for plaque index, DOPI, Hedin index, size of pigmented area, time interval, and extent of repigmentation, at 6 months was statistically nonsignificant. Intergroup comparison for time taken, pain, and patient preference was statistically significant. Intragroup comparison for Nd:YAG laser and surgical stripping at 6 months for DOPI, Hedin index, and size of pigmented area was statistically significant. CONCLUSIONS: From the present study it can be concluded that Nd:YAG laser can be used as an alternative technique for gingival depigmentation. However, surgical stripping continues to remain as a cost-effective procedure.

Low-level laser therapy in the treatment of mucous membrane pemphigoid: a promising procedure.

BACKGROUND: Mucous membrane pemphigoid is a heterogeneous group of autoimmune, subepithelial, blistering diseases. A combination of topical and systemic steroid treatment is often used when managing patients with mucous membrane pemphigoid. The use of systemic steroids presents an increased risk of adverse side effects. Consequently, effective alternative modalities of therapy should be considered, such as the application of low-level laser therapy (LLLT). METHODS: A patient presented with mucous membrane pemphigoid and was successfully treated with the application of local corticosteroids and LLLT using an 810-nm diode laser. The lesions were treated by LLLT over a period of 7 days using a continuous waveform for 40 seconds and an energy density of 5 J/cm(2). RESULTS: After treatment, a significant improvement in tissue color and consistency was observed. The patient was followed every month for a period of 12 months, and the lesions healed uneventfully. CONCLUSION: The results reported in this case show that the healing of mucous membrane pemphigoid was achieved when LLLT was used as an adjunct to the application of a local corticosteroid.

Use of 532-nm Q-switched Nd:YAG laser for smoker's gingival hyperpigmentation.

Laser treatments using 532-/1064-nm Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers are popular non-ablative and selective photothermolysis therapies for pigmentary disorders. We treated three male Korean patients (aged 23, 27 and 24 years) for smoker's gingival hyperpigmentation using a 532-nm Q-switched Nd:YAG laser. At each treatment session, the laser was delivered at 1.2 J/cm(2) with a 5-mm spot size and appropriate overlap. Clinical improvement as well as complete healing of the treated gingiva was noted within 2 weeks after each treatment. We also observed that the therapeutic effects lasted more than 6 months.

The anti-inflammatory mechanism of 635 nm light-emitting-diode irradiation compared with existing COX inhibitors.

BACKGROUND AND OBJECTIVES: Inhibition of cyclooxygenase (COX) and prostaglandin E(2) (PGE(2)) protects cells against cell injury in specific pathophysiological situations: inflammation and oxidative stress. Although the anti-inflammatory effects have been reported in clinical fields for specific wavelength irradiation during wound healing, the physiological mechanism has not been clarified yet. The aim of the present study is to investigate the anti-inflammatory mechanism of 635 nm light-emitting-diode (LED) irradiation compared with existing COX inhibitors. STUDY DESIGN/MATERIALS AND METHODS: The present study investigated anti-inflammatory effects of 635 nm irradiation on PGE(2) release, COX and phospholipase A(2) (PLA(2)) expression, and reactive oxygen species (ROS) dissociation in arachidonic acid (AA)-treated human gingival fibroblast (hGF). These results were compared with their existing COX inhibitors: indomethacin and ibuprofen. The PGE(2) release was measured by enzyme immunoassay, the COX expression was measured by western blot and reverse transcriptase polymerase chain reaction (RT-PCR), and ROS level was measured by flow cytometry, laser scanning confocal microscope and RT-PCR. RESULTS: Results showed that 635 nm irradiation and existing COX inhibitors inhibit expression of COX and PGE(2) release. Unlike indomethacin and ibuprofen, 635 nm irradiation leads to a decrease of ROS levels and mRNA expression of cytosolic phospholipase A(2) (cPLA(2)) and secretary phospholipase A(2) (sPLA(2)). CONCLUSION: Taken together, 635 nm irradiation, unlike indomethacin and ibuprofen, can directly dissociate the ROS. This inhibits cPLA(2), sPLA(2), and COX expression, and results in the inhibition of PGE(2) release. Thus, we suggest that 635 nm irradiation inhibits PGE(2) synthesis like COX inhibitor and appears to be useful as an anti-inflammatory tool.

Lasers and soft tissue: 'fixed' soft tissue surgery.

Within a general practice setting, there are few benign pathological conditions of the attached or keratinised gingival complex that are not amenable to simple surgical intervention. The majority of surgical procedures are adjunctive to the delivery of restorative dentistry. There is an understandable dogma worldwide towards the management of soft tissues as they interface with restorative procedures. Contemporary teaching, both at undergraduate and postgraduate level, would recognise the need for a period of wound healing and stability, based on scalpel-induced incisional therapy. The use of laser wavelengths, based on predictable evidence-based protocols, has re-defined the surgical management of keratinised mucosa that is bound to the underlying periosteum and bone. This can be seen as being of benefit to the clinician in determining the outcome, and the patient in achieving quality results.