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.

A Randomized Comparative Clinical Study to Evaluate the Longevity of Esthetic Results of Gingival Melanin Depigmentation Treatment Using Different Laser Wavelengths (Diode, CO2, and Er:YAG).

Background: Gingival melanin hyperpigmentation is due to excessive deposition of melanin granules. The duration of pigmentation reappearance after treatment using different laser wavelengths remains controversial. Objective: The study aims to assess the longevity of gingival depigmentation (GD) and the consistency in esthetic results as three laser wavelengths (Er:YAG laser, CO2 laser, and diode laser, 980 nm) were used in two different groups (smokers and nonsmokers). This is attained by comparing the periods of time in each group before pigmentation reappearance. Methods: Seventy-two subjects were divided into daily smokers (S) and nonsmokers. Subjects underwent a randomized GD with: Erbium laser (Er), CO2 laser (CO2), and Diode laser (Diode). The subjects were divided into six groups: S and nonsmokers were treated with three different wavelengths. Irradiation was performed until there was no visible pigmentation. For qualitative measurement, Hedin Melanin Index (HMI) was used, before treatment, after 2 weeks, and until 60 months. Pigmentation reappearance of degree 1 or above of the HMI was noted. Descriptive statistics were also calculated. Results: HMI showed a 0 in all groups after 14 days of treatment. The time before pigmentation rebound was: Diode > CO2 > S-Diode > S-CO2 > Er > S-Er. The first signs of relapse shown among all groups were seen in the group S-Er group. The longest time before rebound was observed with the Diode group for the nonsmoker. Conclusions: Diode laser provides the longest-term stability in treatment. Smoking negatively affects the longevity of GD. Er laser gives the shortest time before the reappearance of gingival pigmentation.

Gingival depigmentation using Er:YAG laser and scalpel technique: A six-month prospective clinical study.

OBJECTIVE: To compare the 6-month clinical efficacy of Er:YAG laser and standard scalpel technique in treating gingival hyperpigmentation. METHOD AND MATERIALS: Patients requesting treatment for moderate to severe gingival hyperpigmentation in the maxilla were enrolled in this split-mouth study. The contralateral maxillary sides were randomly assigned to receive either Er:YAG laser (continuous wavelength of 2,940 nm) with a noncontact tip or the standard scalpel technique. Dummett oral pigmentation index (DOPI) and Hedin melanin index (HMI) were compared at the baseline and at 1 and 2 weeks, and 1, 3, and 6 months following the treatment. Bleeding Index, total treatment time, patient preference, pain perception at the first 3 days, wound healing, and level of satisfaction were also compared. Mann-Whitney test, Kruskal-Wallis test, and chi-square test were used to test the significance between variables. A P value of less than or equal to .05 was considered statistically significant. RESULTS: Of the 22 patients enrolled, 20 completed this study. After assessing DOPI and HMI at 1 and 2 weeks, and at 1-, 3-, and 6-month follow-up appointments, both Er:YAG laser and scalpel were significantly effective in treating gingival hyperpigmentation when compared to baseline (P < .001) but with no statistically significant difference between the two treatment methods (P > .05). More patients preferred the scalpel technique as it was associated with slightly shorter treatment time and less postoperative pain when compared to Er:YAG laser, but with no statistical significance (P > .05). Er:YAG laser sites showed minimal bleeding and more rapid wound healing (P < .001). CONCLUSION: Both Er:YAG laser and scalpel technique achieved similar outcomes regarding the efficacy of gingival depigmentation, postoperative pain perception, and the time required for the treatment. Laser therapy requires more advanced technology and is associated with higher financial costs. Therefore, the scalpel technique is still considered the gold standard treatment for gingival depigmentation.

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.

Gingival depigmentation by erbium:YAG laser: clinical observations and patient responses.

BACKGROUND: Melanin, carotene and hemoglobin are the most common natural pigments contributing to the normal color of the gums. Although physiologic and ethnic melanin pigmentation is not a medical problem, complaints about "black gums" are common. Gingival depigmentation has been carried out using non-surgical and surgical procedures. Recently, laser ablation has been recognized as a most effective, pleasant and reliable technique. METHODS: The study included 10 patients who requested cosmetic therapy for melanin pigmented gums. Treatment was carried out using an erbium:YAG laser. The laser beam was set at 500 mJ/10 pulses/second. The beam was defocused to produce a 3 mm diameter circle, thus reducing the beam penetration to 2 to 4 microm/pulse while increasing the treated surface. The "brush" technique was applied until the gingival surface appeared clinically free of pigmentation. Patients were observed for 6 months. Each patient filled out a personal evaluation questionnaire for clinical analysis. RESULTS: Between 500 to 1,100 pulses/cm2 were recorded and a total of 800 to 2,200 pulses were required per patient, depending on the epithelium thickness and pigmentation. Treatment required only topical anesthesia. Healing was uneventful and required no supportive therapy. None of the patients experienced severe pain during or post-operatively. Mild pain or itching was common during the first week. Treatment was reported as generally pleasant. Follow-up during the 6 months showed no recurrences. CONCLUSIONS: Depigmentation of gingival melanin pigmentation by erbium:YAG laser radiation in a defocused mode was a safe and effective procedure. The esthetic results were pleasing and healing was uneventful. Since the erbium:YAG laser is available in the dental office, it seems to be the laser of choice for this procedure.

Láser Er:YAG en Periodoncia. Revisión bibliográfica / Er: YAG laser in periodontic. A review

Diferentes láseres, como el COZ, Nd:YAG y ArF se han propuesto en la terapéutica periodontal. La mayor parte de ellos no han alcanzado relevancia clínica, debido a los resultados insatisfactorios obtenidos en las superficies radiculares tratadas, la generación de efectos colaterales o la ausencia de terminales de aplicación adecuados. Sin embargo, el nuevo láser Er:YAG se muestra como una prometedora alternativa en la remoción de placa bacteriana y cálculo de las superficies radiculares afectas, gracias a su mecanismo de ablación termomecánica y a la ausencia de efectos térmicos secundarios. El propósito de este artículo es revisar las actuales aplicaciones del láser Er:YAG en la práctica periodontal (AU)

Different lasers, such as CO2, the Nd:YAG and the ArF have been proposed for use in periodontal therapy. Most systems have not reached clinical significance because of the unsattisfactory results of laser treated root surfaces, emergence of severe side effects, or the lack of suitable delivery systems. However, the recently introduced Er:YAG laser radiation appears to be a promising alternative means of removing microbial plaque and calculus from diseased tooth root surfaces, due to its thermo-mechanical ablation properties and the lack of thermal side effects. The purpose of this article is to review current applications of laser Er:YAG to periodontal practice (AU)

Radiation therapy for long-term control of odontogenic tumours and epulis in three cats.

Orthovoltage radiation was used to treat odontogenic tumours in three cats following incomplete surgical resection. Cats received a total radiation dose of 48-52 Gy over a period of 26-29 days. Acute toxicities were mild, consisting of hair loss within the radiation field in all cats, and mild mucositis in one cat. All cats had long-term (>35 months) control of their tumour, and two cats are still alive without recurrence of tumour 60 and 39 months, respectively, after completing treatment. Radiation therapy should be considered to be an adjuvant to incomplete surgery in cats with odontogenic neoplasms or epulides.

A clinical study on the removal of gingival melanin pigmentation with the CO(2) laser.

BACKGROUND AND OBJECTIVE: In a previous study, the possibility of removal of dog gingival melanin pigmentation with CO(2) laser therapy was reported. The present study was designed to investigate the effect of the CO(2) laser on human gingival pigmentation and evaluate the clinical outcome. STUDY DESIGN/MATERIALS AND METHODS: A CO(2) laser (output: 6-8 W, pulse duration: 0.2 seconds) was irradiated on the melanin pigmented gingival surface of 10 patients, aged 20-49 years. Follow-up clinical and histopathological evaluations were performed. RESULTS: The CO(2) laser was effective in removing melanin pigmentation in all patients. In the histopathological study, no pigmented-laden cells nor any inflammatory cell infiltration was observed following laser irradiation. No re-pigmentation was seen in any case in the first year. However, four of seven cases showed re-pigmentation at 24 months. The re-pigmentation was almost equal to the preoperative state. CONCLUSIONS: The CO(2) laser has proved to be another effective, safe, and easily applicable therapy for the removal of gingival melanin pigmentation.

Analysis of prognostic factors and patterns of failure in dogs with periodontal tumors treated with megavoltage irradiation.

OBJECTIVE: To determine quality and duration of progression-free survival (PFS) time in dogs with periodontal tumors after definitive megavoltage irradiation and to analyze prognostic factors for PFS time and patterns of treatment failure. DESIGN: Prospective clinical trial. ANIMALS: 47 dogs with acanthomatous, fibromatous, or ossifying epulis. PROCEDURE: Dogs were treated with 48 Gy over 4 weeks on an alternate-day schedule of 4 Gy/fraction. Multivariate analysis was done by use of Cox's proportional hazards regression model to determine prognostic factors for PFS time. RESULTS: The only independent prognostic factor for PFS time was tumor T stage. Pattern of local tumor recurrence (marginal vs infield regrowth) was independent of clinical stage, tumor location, and site. In 4% of the dogs, severe acute radiation reactions in the final week of treatment resulted in treatment discontinuation. In 6.4% of the dogs, chronic radiation reactions included bone necrosis. CLINICAL IMPLICATIONS: Irradiation was a safe and effective treatment of small (T1 and T2 stage) periodontal tumors. The usefulness of the radiation protocol in this study is limited in dogs with large (T3) tumors, particularly those located in the caudal half of the oral cavity, because of poor results and high risk of acute radiation toxicoses.

Treatment of melanotic spots in the gingiva by argon laser.

Dark colored areas, ranging from light blue to black, often occur in the gingiva as a result of the abnormal deposition of melanin. These can develop at any age, creating an unesthetic appearance. The effective elimination of these melanotic areas can be accomplished by treatment with monoline 514 nm green light (1.5 W, 300 milliseconds, 0.5-mm spot size) produced by an argon laser. Restoration of the mucosa is optimal, giving excellent esthetic results.

A study on the removal of the melanin pigmentation of dog gingiva by CO 2 laser irradiation.

Removal of melanin pigmentation of the gingiva with CO 2 laser irradiation was investigated. The melanin-pigmented gingiva of 5 dogs were classified according to the degree of gingival pigmentation (slight, moderate, severe) and its extent (local, extensive). CO 2 laser was irradiated on the surface of the pigmented gingiva under the following conditions; defocused beams of spot size 4 mm, irradiation time 0.2(S), output 6-8(W)). That is, the irradiation energy density was 9.6-12.8 J/cm 2. The irradiated gingiva was examined macroscopically and histopathologically. The histopathological changes were investigated by hematoxylin-eosin staining and Masson staining for the differential diagnosis of melanin pigmentation cells. These examinations were done one week and three weeks after the laser irradiation. Immediately after irradiation, the gingiva surface showed white color and bulla-like appearance. One week after irradiation, the pigmentation of the lased gingiva disappeared in all cases macroscopically. Histologically, the pigmented-laden cells could not be found and no inflammatory cell infiltration was observed. Three weeks after irradiation, no reappearance of pigmentation was observed in either macroscopical or microscopical investigations excluding severe/extensive cases. These findings suggested that it is possible to remove gingival melanin pigmentation by CO 2 laser irradiation.

Adverse effects of pregnancy on multifocal eosinophilic granuloma.

An unusual case of a patient diagnosed as having the histiocytic proliferative disorder characterized by the lesion eosinophilic granuloma (histiocytosis X) is presented. Fifteen-year follow-up revealed a progression from a solitary eosinophilic granuloma of the bone to multifocal involvement of many body structures including the vulva, vagina, and cervix. This progression occurred after nine asymptomatic years and was temporally related to the patient's first pregnancy. After successful treatment and remission, rapid appearance and growth of observable genital lesions were noted during a second pregnancy. Pregnancy termination in the first trimester was advised due to signs of dissemination and local symptoms.