ABSTRACT
Over the past decade, dramatic progress has been made in dental research areas involving laser therapy. The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster. Additionally, photobiomodulation therapy (PBMT), a non-invasive treatment, when applied in orthodontics, contributes to alleviating pain and reducing inflammation induced by orthodontic forces, along with improving tissue healing processes. Moreover, PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption (OIIRR) during orthodontic treatment (OT) due to its capacity to modulate inflammatory, apoptotic, and anti-antioxidant responses. However, a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement (OTM) in relation to OIIRR, casting doubt on its beneficial effects. In PBMT-assisted orthodontics, delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues. The penetration of light to the root surface is another crucial unknown factor. Both the penetration depth and distribution of light in periodontal tissues are unknown. Thus, advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations. This review explores possibilities for improving the application and effectiveness of PBMT during OTM. The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells, with a special focus on immunomodulatory effects during OTM.
Subject(s)
Humans , Inflammation , Low-Level Light Therapy/adverse effects , Orthodontics , Root Resorption/therapy , Tooth Movement TechniquesABSTRACT
Background: Diabetic wound is a major socioeconomic debilitating problem in this society. Various treatment options are available but still it requires better treatment option. In diabetes mellitus the oxygenation to the tissues is reduced. In this study effects of low level laser therapy were compared with topical application of Streptococcus thermophilus on diabetic wounds that induces formation of new blood vessel and free radical scavenging system, a comparative study to get better treatment option for diabetic wounds.Methods: 18 male rats were selected and divided randomly into three groups. Diabetes was induced in all the rats by using the Alloxan monohydrate at a dose of 120mg/kg of the body weight. Group A was treated with normal saline, group B was treated with low level laser therapy and group C was treated with Streptococcus thermophilus topically. Skin tissues were collected on day three and seven, slides were prepared for microscopic examination to observe the new blood vessels formation.Results: Mean number of new blood vessel formation was observed in group B compared with group A and C. Significant vasculogenesis was seen in group B when treated with Low level laser therapy.Conclusions: In the group of low level laser therapy new blood vessel formation was seen with better wound healing. It means LLLT provides better oxygenation to the tissues by generation of new blood vessels compared with Streptococcus thermophilus and normal saline.
ABSTRACT
BACKGROUND: This study investigates the effect of alendronate-treated osteoblasts, as well as the effect of low-level laser therapy (LLLT) on the alendronate-treated osteoblasts. Bisphosphonate decreases the osteoblastic activity. Various treatment modalities are used to enhance the bisphosphonate-treated osteoblasts; however, there were no cell culture studies conducted using a low-level laser. METHODS: Human fetal osteoblastic (hFOB 1.19) cells were treated with 50 μM alendronate. Then, they were irradiated with a 1.2 J/cm² low-level Ga-Al-As laser (λ = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1 cm²; NDLux, Seoul, Korea). The cell survivability was measured with the MTT assay. The three cytokines of osteoblasts, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF) were analyzed. RESULTS: In the cells treated with alendronate at concentrations of 50 μM and higher, cell survivability significantly decreased after 48 h (p < 0.05). After the applications of low-level laser on alendronate-treated cells, cell survivability significantly increased at 72 h (p < 0.05). The expressions of OPG, RANKL, and M-CSF have decreased via the alendronate. The RANKL and M-CSF expressions have increased, but the OPG was not significantly affected by the LLLT. CONCLUSIONS: The LLLT does not affect the OPG expression in the hFOB cell line, but it may increase the RANKL and M-CSF expressions, thereby resulting in positive effects on osteoclastogenesis and bone remodeling.
Subject(s)
Humans , Alendronate , Bone Remodeling , Cell Culture Techniques , Cell Line , Cytokines , Low-Level Light Therapy , Macrophage Colony-Stimulating Factor , Osteoblasts , Osteoprotegerin , SeoulABSTRACT
O presente estudo avaliou a quantidade de mastócitos após irradiação do laser não cirúrgico λ685 nm. Dezoito ratos machos, linhagem Wistar (250 a 300 gramas), nos quais foram realizadas feridas cirúrgicas padronizadas, foram distribuídos em seis grupos, três experimentais (com quatro ratos) e três controles (com dois ratos). Os grupos experimentais foram irradiados em quatro pontos perilesionais equidistantes (0,5 J/cm², 35 mW, 35 Hz e 17 segundos). Os grupos-controles não foram irradiados. Os animais foram mortos 6, 12 e 24 horas após a irradiação, sendo obtidas peças que seguiram para processamento laboratorial de rotina. O estudo das lâminas foi realizado por meio da contagem absoluta dos mastócitos pelo método esteriológico. Os resultados obtidos demonstraram que, nas primeiras 6 e 12 horas, após a irradiação laser, existe uma diminuição no número total de mastócitos, estatisticamente significante, quando comparados aos grupos controles, porém, após 24 horas, não existem diferenças no número de mastócitos entre os grupos experimental e controle. Baseados nos resultados obtidos com o protocolo de aplicação da luz laser utilizado, para esse modelo animal, pôde-se concluir que a luz laser é capaz de diminuir o número total de mastócitos após uma única irradiação.
This study measured the variation in the total number of mast cells after low level laser therapy (λ= 685 nm) using a stereological method. Eighteen male Wistar rats (250 to 300 grams) with standardized surgical wounds were randomly distributed into 6 groups - 3 study groups with 4 rats each, and 3 control groups with 2 rats each. In the study groups, four equidistant spots around the standardized wound were irradiated (0.5 J/cm², 35 mW, 35 Hz, 17 seconds). The control groups were not irradiated. The animals were killed at 6, 12 and 24 hours after laser therapy. Biological specimens were harvested and routinely processed; slides were prepared and stained with toluidine blue. The total number of mast cells was counted using the stereological method. A statistically significant decrease in the total number of mast cells was observed at 6 and 12 hours after irradiation. However, there was nodifference in the number of mast cells between study and control groups at 24 hours. Our results showed that one single irradiation with laser light reduced the total number of mast cells in the animal model used in this study.
ABSTRACT
O objetivo deste trabalho foi estudar a intensidade do infiltrado inflamatório agudo, presente em tecido conjuntivo perilesional do dorso de ratos submetidos à irradiação laser de baixa potência (λ 685 nm) após uma única aplicação. Foram utilizados dezoito ratos machos, linhagem Wistar, de 250 a 300 gramas, nos quais foram realizadas feridas cirúrgicas padronizadas. A amostra foi constituída de seis grupos, três experimentais e três controles, compostos por quatro e dois ratos, cada grupo, respectivamente. Os grupos experimentais foram irradiados em quatro pontos perilesionais equidistantes, com uma única dose de 0,5J/cm² por ponto, com potência de 35 mW, frequência de 35 pulsos por segundo e tempo de aplicação por ponto de 17 s. Os grupos-controles não foram irradiados. Os animais foram mortos 6, 12 e 24 horas após a irradiação, sendo obtidas peças que seguiram para processamento laboratorial de rotina. O estudo das lâminas foi realizado através da descrição e contagem absoluta dos granulócitos pelo método esteriológico. Os resultados obtidos demonstraram que há uma diminuição no número total de granulócitos, não significante estatisticamente (p≥0,05), quando comparados aos grupos controles. Concluiu-se que a luz laser é capaz de diminuir a intensidade do infiltrado inflamatório após uma única irradiação.
The aim of this work was study the intensity of acute inflammatory infiltrate inconnective tissue after low level laser therapy (λ = 685 nm) irradiation. Eighteen maleWistar rats (250 to 300 grams) with standardized surgical wounds were randomlydistributed into 6 groups - 3 study groups with 4 rats each, and 3 control groups with2 rats each. In the study groups, four equidistant spots around the standardizedwound were irradiated (0.5 J/ cm², 35 mW, 35 Hz, 17 seconds). The control groupswere not irradiated. The animals were killed at 6, 12 and 24 hours after laser therapy.Biological specimens were harvested and routinely processed. The total number of granulocyteswascounted using the stereological method. A non-statistically significant decrease in thetotal number granulocytes was observed in the all study groups. Our results showedthat one single irradiation with laser light reduced the total number of graunulocytesin the animal model used in this study.
ABSTRACT
The concept of biostimulation of wounds by low-level laser therapy (LLLT) is attracting considerable attention. Although its effect on whole tissues has been studied quite extensively, the biological and cellular mechanisms underlying LLLT have not been clarified. In an experimental radius fracture in rabbits, Tang and Chai reported that LLLT enhanced the activity of red blood cells, macrophages, fibroblasts, chondrocytes, and osteoclasts within the fracture area. The purpose of the present study was to evaluate the effect of LLLT with a GaAlAs diode laser device on bone healing in rabbit mandibular fractures. We use 12 rabbits for this study. All rabbits were fractured mandible angle area using saw in anesthetic condition. In control group(n=6), none treatment was performed at fracture site. In experimental group(n=6), LLLT with a GaAlAs diode laser was radiated at fracture site daily for 7 days. All rabbits were sacrificed at 6 weeks later from performed fracture day. We studied the immunohistochemical staining of CD34 and Vimentin and the histochemical analysis for calcium and phosphorus content. The results were as follows. 1. In the histological and immunohistological staining, after 6week, fibroblasts, osteogenic cells and collgen fibers were observed more in experimental group than in control group. 2. In the histochemical analysis, the amount of calcium and phosphorus contents of the experimental group were more than the control group. From the results obtained, we suggest that the bone healing is stimulated by low-level laser irradiation in bone fractures.