Low-level Laser Irradiation Research Articles

The proliferation and viability of human periodontal ligament stem cells cultured on polymeric scaffolds can be improved by low-level laser irradiation.

This study assessed the impact of low-level laser irradiation on the viability and proliferation of human periodontal ligament stem cells (hPDLSCs) cultivated on polylactic acid (PLA) scaffolds. hPDLSCs were obtained, characterized, and grown on the surface of PLA films produced via the solvent casting technique. The study involved two groups: the control group, which was not exposed to radiation, and the laser group, which was irradiated with a diode laser (InGaAIP) with a power of 30 mW, a wavelength of 660 nm, and a single dose of 1 J/cm² emitted continuously. Cell viability was assessed 24 and 48 hours after irradiation using the Alamar blue and Live/Dead assays. Flow cytometry was used to assess cell cycle events, and scanning electron microscopy (SEM) was used to evaluate the interaction between cells and the biomaterial. The results revealed a statistically significant increase in cell metabolic activity in the laser group compared with the control group at 24 hours (p <0.05) and 48 hours (p <0.001), as indicated by the Alamar blue assay. The Live/Dead assay also revealed a greater density of viable cells in the laser group. The cell cycle analysis revealed a significant increase in the number of cells in the proliferative phase (G2/M) in the laser group compared with the control group (p <0.001). The SEM images demonstrated that the irradiated group had a greater concentration of cells while still maintaining their cell shape and projections. This study demonstrated that photobiomodulation can increase the viability and proliferation of periodontal stem cells cultured on PLA scaffolds, suggesting the potential of this protocol for future studies on periodontal tissue engineering.

A comparative study of 589 and 532 nm low level laser irradiation effects on normal human peripheral blood mononuclear cells viability.

To assess how laser light affects blood lymphocyte viability in vitro. The comparative study was conducted from November 2021 to April 2022 at the Department of Medical Physics, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples collected from healthy adults with no medical history of major illnesses or history of taking medications for major diseases.Low-level laser 589nm and 532nm was used at 30 J/cm², 50 J/cm² and 70J/cm² energy intensities and three different post-exposure time; immediately, 1h and 2h after radiation exposure. The viability of normal human lymphocytic cells of the blood was noted. Data was analysed using SPSS 24. The blood samples were drawn from 6 adult male voluteers. The percentage of cells that showed apoptosis post-exposure to 589nm laser was significantly lower than that following exposure to 532nm laser (p<0.05). However, the proportion of apoptotic cells was significantly higher following irradiation with 532nm at varying doses than after irradiation with 589nm (p<0.05). A low-level laser could promote and prevent apoptosis in human peripheral blood cells in a dose- and time-dependent manner.

The effect of a diode-pumped solid-state laser with a wavelength of 589 nm on T-lymphocyte proliferation.

To assess how low-level laser irradiation affects T cells. The case-control interventional study was conducted from November 2021 to April 2022 after approval by the ethics review committee of the College of Medicine, Mustansiriyah University, Baghdad, Iraq, and comprised healthy individuals. Phlebotomy was used to collect 4ml of blood. A portion of each sample was exposed to 589nm laser radiation, while the other portion was used as a control. The irradiated sample was divided into whole blood and in-plate subgroups. Phytohemagglutinin was used for mitotic stimulation of T-lymphocytes, and cell proliferation assay was used to stimulate T lymphocytes measured using MTS assay (3-(4,5-dimethylthiazol-2-yl)-5- (3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium). Optical density was measured using enzyme-linked immunosorbent assay. Data was analysed using GraphPad prism software. There were 35 subjects, 17(49%) males and 18 (51%) females, with an age range between 19-25 years, all without any disease or medication. Laser irradiation stimulated T-lymphocyte proliferation to levels that depended on the dose of laser used. At energy 30J/cm2 there was a significant increase in the in-plate subgroup of irradiated samples compared to controls and between the two irradiated subgroups (p<0.05). At 50J/cm2 dose, there was a significant increase in the whole blood subgroup compared to the controls (p<0.05). At 70J/cm2 dose, there was a significant difference in the whole blood subgroup compared to the controls, and between the two irradiated subgroups (p<0.05). The stimulation of T lymphocyte proliferation by the application of a 589nm laser could have medical applications in the field of immune system enhancement.

Effect of 532nm and 589nm Diode-Pumped Solid-State (DPSS) Lasers with Different Doses on Concentration of Total Protein and Albumin in Vitro.

To test the effects of Low-level laser irradiation at 532nm and 589nm with different doses and exposure times on total protein and albumin in blood plasma. This experimental study was conducted from November 2021 to April 2022 at Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy adults. The samples were stored in tubes containing anticoagulant ethylenediaminetetraacetic acid. Photoradiation was managed using green laser 532nm and yellow laser 589nm diode-pumped solid-state lasers with different doses. For total protein test and albumin test, each sample was divided into 3 equal aliquots. The first was control without radiation, the second was irradiated by a laser at 532nm, and the third was irradiated at 589nm with 30J/cm², 50J/cm², 70J/cm² and 90 J/cm² doses of irradiation. All samples were examined by using a spectrophotometer device. Data was analysed using SPSS 25. There were 24 samples from healthy adults in all.The most significant difference in total protein concentration occurred at dose 70J/cm² for both wavelengths compared to the controls (p<0.05). When this optimal dose was applied to the albumin test, a clear decrease in the albumin concentration was found for both 532nm and 589nm lasers (p<0.05). At wavelengths of 532nm and 589nm, the laser light induced processes that caused a reduction in total protein and albumin.

A comparison study of 589 and 650 nm on improving stored whole blood stability by irradiation with a low-power diode pumping solid-state laser.

To assess the effects of diode-pumped solid-state laser irradiation with 589nm and 650nm wavelengths on the stability of stored red blood cells in vitro. This is an intervention study that was conducted from April to July 2021 at the Physiology and Medical Physics Laboratory, College of Medicine, Mustansiriyah University, Baghdad, Iraq, and comprised samples of healthy, adult human blood that were put in tubes with citrate-phosphate dextrose-adenine as an anticoagulant. The blood sample was divided into eight equal aliquots and stored for 21 days at 4ºC. The stability test was done on days 0, 7, 14 and 21 of storage time for non-irradiated and radiated aliquots. For 15 minutes, the irradiated aliquots were subjected to a diode-pumped solid-state laser with a wavelength of 589nm or a laser with a wavelength of 650nm at frequencies of 30, 50 and 70 J/cm². Data was analysed using SPSS 24. Exposure of the whole blood to 589nm and a radiation dose of 70J/cm², 50J/cm² and 30J/cm² was associated with a significant reduction in the percentage of haemolysis that ranged 23-42% throughout the whole storage time. Exposure of the whole blood to 650nm wavelength low-level laser therapy and a radiation dose of 70J/cm², 50J/cm² and 30J/cm² was associated with much less reduction in the percentage of haemolysis that ranged 5-9% throughout the whole storage time. Both 589nm and to some extent 650nm low-level laser irradiation generally reduced haemolysis. The wavelength of 589nm lasers had a more effective influence than the 650nm counterpart in improving the stored red blood cells.

The Effect of Cold Plasma and Low-Level Laser Therapy on Oral Fibroblast Proliferation

Background: Wound healing is a complex physiological process involving multiple phases and cellular mechanisms that restore damaged tissue. The oral cavity presents unique challenges for wound healing due to the presence of microorganisms and the impact of various diseases and treatments. Recent advancements, including low-level laser therapy (LLLT) and cold plasma, offer promising approaches to enhance wound healing by promoting cell proliferation and reducing inflammation. This study aimed to investigate the effects of cold plasma and low-level 980nm laser on the growth of oral fibroblasts and compare their respective impacts on wound healing. Methods: Human gingival fibroblasts were divided into nine study groups, including a control group. Two groups were exposed to low-level 980nm diode laser irradiation for 15 and 30 seconds, while six groups received cold plasma irradiation with helium gas at flow rates of 1.85, 2.78 and 5.56 cm3/s for the same durations. Fibroblast proliferation was evaluated on days 1, 3, and 5 after treatment using the MTT assay. Results: The results showed that on the 5th day after irradiation, 30 seconds of 980 nm laser irradiation significantly increased fibroblast proliferation compared to the other groups. In contrast, 15 seconds of plasma irradiation at a flow rate of 1.85 cm3/s had the least effect on promoting fibroblast proliferation. On the 1st day after radiation, plasma irradiation at flow rates of 2.78 and 5.56 cm3/s exhibited a greater impact on fibroblast proliferation compared to the other five test groups. Conclusion: The 980nm diode laser demonstrated a greater capacity to enhance the proliferation of oral fibroblasts compared to cold plasma using helium gas.

Low-level laser irradiation inhibits migration and proliferation of vascular endothelial cells and upregulates miR-143

Low-level laser irradiation inhibits migration and proliferation of vascular endothelial cells and upregulates miR-143

Methodological notes on physical parameters of low-level laser irradiation. Part 1. Penetration depth of laser light

Methodological notes on physical parameters of low-level laser irradiation. Part 1. Penetration depth of laser light

A Comprehensive Systematic Review of the Effects of Photobiomodulation Therapy in Different Light Wavelength Ranges (Blue, Green, Red, and Near-Infrared) on Sperm Cell Characteristics in Vitro and in Vivo.

Around 7% of the male population in the world are entangle with considerable situation which is known as male infertility. Photobiomodulation therapy (PBMT) is the application of low-level laser radiation, that recently used to increase or promote the various cell functions including, proliferation, differentiation, ATP production, gene expressions, regulation of reactive oxygen spices (ROS), and also boost the tissue healing and reduction of inflammation. This systematic review's main idea is a comprehensive appraisal of the literatures on subjects of PBMT consequences in four light ranges wavelength (blue, green, red, near-infrared (NIR)) on sperm cell characteristics, in vitro and in vivo. In this study, PubMed, Google Scholar, and Scopus databases were used for abstracts and full-text scientific papers published from 2003-2023 that reported the application of PBM on sperm cells. Criteria's for inclusion and exclusion to review were applied. Finally, the studies that matched with our goals were included, classified, and reported in detail. Also, searched studies were subdivided into the effects of four ranges of light irradiation, including the blue light range (400-500 nm), green light range (500-600 nm), red light range (600-780 nm), and NIR light range (780-3000 nm) of laser irradiation on human or animal sperm cells, in situations of in vitro or in vivo. Searches with our keywords results in 137 papers. After primary analysis, some articles were excluded because they were review articles or incomplete and unrelated studies. Finally, we use the 63 articles for this systematic review. Our category tables were based on the light range of irradiation, source of sperm cells (human or animal cells) and being in vitro or in vivo. Six% of publications reported the effects of blue, 10% green, 53% red and 31% NIR, light on sperm cell. In general, most of these studies showed that PBMT exerted a positive effect on the sperm cell motility. The various effects of PBMT in different wavelength ranges, as mentioned in this review, provide more insights for its potential applications in improving sperm characteristics. PBMT as a treatment method has significant effectiveness for treatment of different medical problems. Due to the lack of reporting data in this field, there is a need for future studies to assessment the biochemical and molecular effects of PBMT on sperm cells for the possible application of this treatment to the human sperm cells before the ART process.

Low-level laser activates Wnt/β-catenin signaling pathway-promoting hair follicle stem cell regeneration and wound healing: Upregulate the expression of key downstream gene Lef 1.

The objective of this study is to investigate the mechanism by which low-level laser stimulation promotes the proliferation of intraepithelial hair follicle stem cells (HFSCs) in wounds. This research aims to expand the applications of laser treatment, enhance wound repair methods, and establish a theoretical and experimental foundation for achieving accelerated wound healing. The experimental approach involved irradiating a cell model with low-level laser to assess the proliferation of HFSCs and examine alterations in the expression of proteins related to the Wnt/β-catenin signaling pathway. A mouse back wound model was established to investigate the effects of low-level laser irradiation on wound healing rate, wound microenvironment, and the proliferation of HFSCs in relation to the Wnt/β-catenin signaling pathway. The research findings indicate that low-level laser light effectively activates the Wnt signaling pathway, leading to the increased accumulation of core protein β-catenin and the upregulation of key downstream gene Lef 1. Consequently, this regulatory mechanism facilitates various downstream biological effects, including the notable promotion of HFSC proliferation and differentiation into skin appendages and epithelial tissues. As a result, the process of wound healing is significantly accelerated. Low levels of laser activates the Wnt signalling pathway, promotes the regeneration of hair follicle stem cells and accelerates wound healing.

Simultaneous effect of medicinal plants as natural photosensitizers and low-level laser on photodynamic inactivation.

Photodynamic inactivation (PDI) technology is a promising alternative to antibiotics. This technology is defined as the inhibition of bacterial growth with photosensitizers while irradiated with low-level laser light in the wavelength of 532 ± 2.08nm. A challenging area in this field is selecting photosensitizers with antibacterial potential. In this paper, to enhance the antibacterial efficiency, the photosensitizers (the selected plant extracts) with a high absorption peak at the selected laser frequency, 532nm, were prepared. Low-concentration ethanolic plant extracts of Hibiscus sabdariffa and Opuntia ficus-indica were found to exhibit significant antibacterial activity against, Acinetobacter baumannii ATCC 19606 and, Staphylococcus aureus ATCC 33591 as two important human pathogenic bacteria. The effectiveness of these natural photosensitizers was measured by determining their Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values and by performing a time-killing assay in the absence and the presence of laser irradiation. Our results showed that the combination of low-level laser irradiation and the selected photosensitizers had excellent potential for treating in vitro bacterial infections. Therefore, PDI technology has great potential as a viable alternative to traditional antibiotics for combating bacterial infections. This study presents a promising avenue for further exploration of PDI and the use of laser technology in medical science.

Low-level laser therapy alleviates periodontal age-related inflammation in diabetic mice via the GLUT1/mTOR pathway.

Diabetes mellitus (DM) is a chronic age-related disease that was recently found as a secondary aging pattern regulated by the senescence associated secretory phenotype (SASP). The purpose of this study is to detect the potential efficacy and the specific mechanisms of low-level laser therapy (LLLT) healing of age-related inflammation (known as inflammaging) in diabetic periodontitis. Diabetic periodontitis (DP) mice were established by intraperitoneal streptozotocin (STZ) injection and oral P. gingivalis inoculation. Low-level laser irradiation (810nm, 0.1W, 398mW/cm2, 4J/cm2, 10s) was applied locally around the periodontal lesions every 3days for 2 consecutive weeks. Micro-CT and hematoxylin-eosin (HE) stain was analyzed for periodontal soft tissue and alveolar bone. Western blots, immunohistochemistry, and immunofluorescence staining were used to evaluate the protein expression changes on SASP and GLUT1/mTOR pathway. The expression of aging-related factors and SASP including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 were reduced in periodontal tissue of diabetic mice. The inhibitory effect of LLLT on GLUT1/mTOR pathway was observed by detecting the related factors mTOR, p-mTOR, GLUT1, and PKM2. COX, an intracytoplasmic photoreceptor, is a key component of the anti-inflammatory effects of LLLT. After LLLT treatment a significant increase in COX was observed in macrophages in the periodontal lesion. Our findings suggest that LLLT may regulate chronic low-grade inflammation by modulating the GLUT1/mTOR senescence-related pathway, thereby offering a potential treatment for diabetic periodontal diseases.

Assessment of BMI in obese patients after semiconductor laser acupuncture therapy

Background/aim There is an urgent need to diminish BMI due to the increased prevalence of chronic critical diseases accompanied by overweight and obesity. Laser acupuncture (LA) is a complementary modality that might lower the BMI by diminishing the abdominal and visceral adipose tissue content and influencing the regulation of the lipid metabolism process. It is a painless tool which is almost free from side effects. The aim of the present study is to assess the BMI in obese patients after semiconductor LA therapy. Patients and methods This is a randomized clinical trial study that enrolled 111 obese patients who visited the Acupuncture and Laser Clinic, Excellence Medical Centre, National Research Centre, Cairo, Egypt. They received 19 successive LA sessions for 2 months without any intervention concerning their routine lifestyle. Low-level laser irradiation was applied at certain acupuncture points according to the principles of Traditional Chinese Medicine. Laser parameters were wavelength 850 nm, and power density 200 mW. Calculated energy 6 J/cm2 for 24 s per acupoints. The anthropometric measurements were done on all participants before and after the end of LA sessions. Results The present result indicated that there is a significant decrease in weight (P&lt;0.05), with a percent of changes –5.8%. Additionally, the BMI showed a significant decrease (P&lt;0.05), with a percent of changes –6.1% after 2 months of stimulated LA sessions compared to before laser therapy. Also, more than 15 sessions gave 95% sensitivity, 100% specificity for successful significant response, and the number of LA sessions had a significant good utility in predicting successful responses in weight reduction and BMI management. Conclusion The upgrading of the conducted LA sessions had a promising value in different grades of obesity and was safely applicable for BMI management.

In Vitro Effect of Low-Level Lasers on Total Bilirubin Concentration in Human Blood Plasma Using 375 and 650 nm Lasers.

Background: The current research extends previous laboratory investigations by investigating the effects of low-level laser irradiation (LLLI) on human blood plasma. Total bilirubin is of special importance because of its potential biostimulatory and modulatory actions. Objective: This study aims to analyze changes in total bilirubin content as a consequence of LLLI on human blood plasma. This study aims to determine how changes in exposure duration and laser wavelength affect these adjustments. Methodology: Plasma was isolated from a healthy adult donor's whole blood using the anticoagulant ethylenediaminetetraacetic acid (EDTA). Plasma samples were exposed to LLLI at 375 and 650 nm for 5, 10, 15, 20, and 25 min. Total bilirubin concentrations were measured both before and after irradiation using spectrophotometric analysis. The difference between 375 and 630 nm lasers was also investigated. Results: Five, 10, 15, 20, and 25 min of exposure to LLLI at 375 and 650 nm wavelengths resulted in statistically significant differences in total bilirubin content (p ˂ 0.05, p ˂ 0.001, p ˂ 0.0001). There was no statistically significant difference in total bilirubin concentration between the 375 and 630 nm lasers. Conclusions: Human blood plasma total bilirubin levels were considerably lower following LLLI at 375 and 630 nm than controls. Multiple exposures provide the same results. These findings demonstrate the role of biostimulation by laser irradiation in blood plasma applications and suggest that low-level laser treatment may control total bilirubin levels, particularly at 375 and 630 nm.

Enhanced periodontal tissue healing via vascular endothelial growth factor expression following low-level erbium-doped: yttrium, aluminum, and garnet laser irradiation: In vitro and in vivo studies.

This study aimed to investigate the effects of low-level erbium-doped: yttrium, aluminum, and garnet (Er:YAG) laser irradiation on periodontal tissue healing and regeneration through angiogenesis in vivo and in vitro studies. Intrabony defects were surgically created in the bilateral maxilla molar of rats. The defects were treated by open flap debridement (OFD)with Er:YAG laser, including low-level laser irradiation (LLLI) to bone and blood clot surfaces, or conventional procedures. The mRNA expression of vascular endothelial growth factor (VEGF) in the surgical sites was quantified using real-time polymerase chain reaction. The decalcified specimens were prepared for histometric analysis. Also, LLLI was performed on human umbilical vein endothelial cells to evaluate the effects on angiogenesis. Cell proliferation, VEGF expression, and tube formation were assessed. In addition, capsazepine (CPZ), a selective inhibitor of transient receptor potential vanilloid 1 (TRPV1), treatment was performed before LLLI for the same assays. OFD using Er:YAG laser did not generate thermal damage on bone or root surfaces. LLLI accelerated hemostasis by coagulation of the superficial layers of blood clots in the laser-treated group. Postoperative healing was sound in all animals in both groups. VEGF expression and bone formation were significantly increased in the laser-treated group compared to those in the conventional treatment group. In vitro, cell proliferation and VEGF expression were significantly increased in the LLLI group compared to the control group. Tube-formation assays showed that LLLI significantly promoted angiogenesis. CPZ treatment significantly suppressed VEGF expression and tube formation following LLLI. This study suggests that Er:YAG laser irradiation may promote periodontal tissue healing by enhancing angiogenetic effect of endothelial cells via TRPV1.

Effect of Low-Level Laser Irradiation (810 nm) on the Proliferation and Differentiation of Osteoblast-Like Cells Cultured on SLA Titanium Discs Exposed to a Peri-implantitis Environment.

Introduction: Elimination of inflammation and re-osseointegration are the major objectives of peri-implantitis therapy. Existing data, however, do not support any decontamination approach. Thus, the present in vitro study aims to assess whether the air-debriding decontamination method with erythritol powder restores the biocompatibility of infected titanium discs and to investigate the potent biomodulatory ability of diode laser (810 nm) irradiation to promote cell proliferation and differentiation of premature osteoblast-like cells (MG63) towards osteocytes. Methods: The experimental groups consisted of cells seeded on titanium discs exposed or not in a peri-implantitis environment with or without biomodulation. Infected discs were cleaned with airflow with erythritol powder. Cell cultures seeded on tricalcium phosphate (TCP) surfaces with or without biomodulation with a laser (810 nm) were used as controls. The study evaluated cell viability, proliferation, adhesion (SEM) at 24, 48 and 72 hours, and surface roughness changes (profilometry), as well as the effects of low-level laser therapy (LLLT) on ALP, OSC, TGF-b1, Runx2, and BMP-7 expression in MG63 cells' genetic profile on days 7, 14, and 21. Results: The MTT assay as well as the FDA/PI method revealed that cell proliferation did not show significant differences between sterile and decontaminated discs at any timepoint. SEM photographs on day 7 showed that osteoblast-like cells adhered to both sterile and disinfected surfaces, while surface roughness did not change based on amplitude parameters. The combination of airflow and LLLT revealed a biomodulated effect on the differentiation of osteoblast-like cells with regard to the impact of laser irradiation on the genetic profile of the MG63 cells. Conclusion: In all groups tested, osteoblast-like cells were able to colonize, proliferate, and differentiate, suggesting a restoration of biocompatibility of infected discs using airflow. Furthermore, photomodulation may promote the differentiation of osteoblast-like cells cultured on both sterile and disinfected titanium surfaces.

Intravascular laser irradiation of blood as novel migraine treatment: an observational study

BackgroundMigraine is one of four major chronic diseases that cause disability. Decreases in regional cerebral blood flow (rCBF) occur during migraine attacks. Laser therapy is extensively employed in treating other vascular diseases; nevertheless, its effectiveness in migraine management remains largely unknown. Therefore, we evaluated the effect of low-level intravascular laser irradiation of blood (ILIB) therapy in patients with migraine.MethodsWe performed an observational case–control study in 24 patients suffering from migraine. Patients were divided into an ILIB treatment group and a traditional rehabilitation group. This study performed clinical assessments and single-photon emission computed tomography (SPECT) prior to and after the treatment and 1 month later. Changes in rCBF-SPECT between groups and between timepoints were compared to clinical outcomes.ResultsNine patients undergoing rehabilitation and fifteen patients undergoing ILIB were studied from baseline to 1 month follow-up. The ILIB group, visual analog scale for pain (P = 0.001), Montreal Cognitive Assessment (P = 0.003), and Athens Insomnia Scale (P < 0.001) symptom scores significantly improved after treatment. SPECT imaging showed a 1.27 ± 0.27 fold increase in rCBF after ILIB treatment, and no significant differences in the rehabilitation group.ConclusionsLow-level ILIB therapy is associated with better clinical and vascular outcomes, and may be a feasible treatment option for migraine. Although our sample size was small, our data provide a starting point for migraine laser therapy research.

To evaluate the effects of Low-level laser therapy (LLLT) on wound healing of extraction socket: A systematic review

Background: Low power laser therapy or low-level laser therapy (LLLT) is relatively novel and has demonstrated tremendous advantages in dentistry which includes reduction in post-surgical pain as well as swelling and also accelerates wound healing and helps in bone regeneration etc. Objective: This systematic review aimed to find out whether low-level laser therapy promotes tooth extraction wound healing. Materials and Methods: Literature was searched from January 2010 till 31 December 2020 using PubMed, Scopus, and Web of science. Further findings were done from gray literature google scholar, and Research Gate using Low-level laser therapy, photobiomodulation, wound healing, extraction socket healing, cold laser, biostimulation, low-level laser irradiation, and phototherapy. Any article that reported effects of low-level laser therapy on wound healing was included. 19 studies fulfilled the criteria and were included for this systematic review. Quality assessment was done for each article using Joanna Briggs Institute (JBI) checklist for analytical cross-sectional studies. Results and Discussion: Throughout the search, approximately 22,808 relevant articles were found. Out of which 50 articles fulfilled the selection criteria. 31 articles were excluded because that did not fulfill inclusion criteria. 19 articles were included for this systematic review that compared the effects of low level-laser therapy on wound healing after extraction of a tooth. Conclusion: Overall, this systematic review concluded that low-level laser therapy enhanced the process of wound healing after extraction of teeth but most of the research was conducted on animals. Further research is needed to investigate the biostimulatory effects of low-level irradiation on wound healing after extraction of a tooth Bangladesh Journal of Medical Science Vol. 22 No. 03 July’23 Page : 585-597

Evaluation and comparison of the effect of ozone therapy and photodynamic therapy in non-surgical management of chronic periodontitis

Among the non-invasive therapies to achieve better plaque control, photodynamic therapy (PDT) and ozonated water therapy (OT) are being widely recognized as two reliable techniques. PDT using low-level laser irradiation is known to selectively target the periodontal pathogens without potentially damaging the host tissues. Ozone therapy on the other hand has antimicrobial, analgesic, immune-stimulating, immune-modulatory, and anti-inflammatory properties, it also oxygenates tissues and enhances their regeneration potential. It has been proven to strongly inhibit the formation of dental plaque. Objective: To evaluate and compare the effect of ozonated oil therapy (OT) and photodynamic therapy (PDT) in nonsurgical management of chronic periodontitis. Methodology: Twelve patients diagnosed with chronic generalized periodontitis were subjected to the study. Following the assessment of gingival index, periodontal pocket depth, and clinical attachment loss, all patients underwent full-mouth scaling and root planing. The study had a split-mouth design, one quadrant of each patient was subjected to ozonated oil therapy with a 22-gauge needle and the contralateral quadrant was treated with PDT, using indocyanine green dye. Patients were recalled after one month and the clinical parameters were recorded again. Results: A statistically significant reduction was observed in all the clinical parameters in both the study groups at 1 month follow up period. Conclusion: Results showed that there was equal improvement in the clinical outcomes in both the groups. Key words: Chronic periodontitis, Ozone therapy, Photodynamic therapy

Influence of Three Laser Wavelengths with Different Power Densities on the Mitochondrial Activity of Human Gingival Fibroblasts in Cell Culture.

Phototherapy plays a key role in wound healing and tissue regeneration. The use of lasers has the potential to become an effective and minimally invasive treatment in periodontal and peri-implant disease. The aim of this study was to evaluate the influence of three laser wavelengths with the combination of parameters such as power density and energy density on human gingival fibroblasts (hGFs) in vitro culture. Isolated cells were seeded in 96-well plates with culture medium (DMEM, Dulbecco's modified Eagle's medium) supplemented with 10% fetal bovine serum (FBS). After 24 h cells were irradiated (1064, 980 and 635 nm, various energy density value). After 24, 48 and 72 h, cells were evaluated for viability. Data were analyzed by ANOVA followed by Tukey's HSD test. We found the best outcomes for hGFs irradiated with laser 1064 nm for all combinations of power output (50/400/1000 mW) and energy dose (3/25/64 J/cm2) after 48 h and 72 h compared with control group. Cell viability increase ranged from 0.6× (3 J/cm2, 50 mW) to 1.3× (64 J/cm2, 1000 mW). Our findings indicate that the appropriate use of low-level laser irradiation (LLLI) can increase the proliferation rate of cultured cells. The use of LLLI can be extremely useful in tissue engineering and regenerative medicine.