Anti-Inflammatory effects of low-level laser therapy (660 nm) in the early phase in carrageenan-induced pleurisy in rat

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Effect of photobiomodulation therapy on headache, and fatigue in patients with chronic rhinosinusitis: a randomized controlled study

Chronic rhinosinusitis (CRS) is a debilitating disease that resists medical treatment. Photobiomodulation therapy is one of the promising treatment modalities for CRS. The purpose is to investigate the effect of photobiomodulation therapy on headache, fatigue, sinus opacification, and ostiomeatal complex obstruction in patients with CRS. Thirty-one patients with CRS were randomly divided into photobiomodulation therapy and control groups. The photobiomodulation therapy group received photobiomodulation therapy (2.5 J, frequency 9.12 Hz, and 904 nm for 10 min for 12 sessions) on eight rhinosinusitis sites, and the control group received a sham laser. Headache, fatigue, and sinus opacification outcomes were measured before and after treatment. There was a significant improvement in headache, fatigue, and sinus opacification in the photobiomodulation therapy group in comparison with the control group (p < 0.05). Photobiomodulation therapy is an effective physical therapy treatment modality for the management of CRS.Clinical trial registry: NCT05861817.

Shedding Light on Photobiomodulation Therapy for Age-Related Macular Degeneration: A Narrative Review

BACKGROUND

Photobiomodulation (PBM) relies on the pathophysiological mechanism whereby red to near-infrared light can target mitochondrial activity and promote ATP synthesis. Preclinical and clinical studies have shown promising results in treating intermediate age-related macular degeneration (AMD), since PBM can produce photochemical reactions in endogenous retinal chromophores. Currently, PBM is approved by the Food and Drug Administration and by the European Medicines Agency for the treatment of intermediate AMD. This narrative review aimed to evaluate the available evidence on the effectiveness and safety of PBM in treating intermediate AMD.

METHODS

A comprehensive search was conducted using the PubMed database, employing the keywords "photobiomodulation" and "age-related macular degeneration." All English-language studies published up to June 2023 were reviewed, and the search was expanded to include relevant references from selected articles. The included publications were analyzed for this review.

RESULTS

The available studies on PBM in AMD demonstrated promising but inconsistent results. PBM showed potential in improving best-corrected visual acuity (BCVA) and contrast sensitivity (CS) in patients with AMD. Some studies also suggested a reduction in AMD lesions, such as drusen volume. However, the long-term efficacy and optimal treatment parameters of PBM in AMD remained to be fully determined due to the limitations of the available studies. These included variations in irradiation techniques, wavelengths, exposure times, and treatment sessions, making it challenging to generalize the effectiveness of PBM. Furthermore, the lack of accurate classification of AMD phenotypes in the available studies hindered the understanding of which phenotypes could truly benefit from this treatment. Finally, the strength of evidence varied among studies, with limited sample sizes, unpublished results, and only three randomized sham-controlled trials.

CONCLUSIONS

Currently, the effectiveness of PBM in promoting drusen resorption or preventing progression to advanced forms of AMD, as observed in the cited studies, remains uncertain.

Efficacy of Combined Photobiomodulation Therapy with Supplements versus Supplements alone in Restoring Thyroid Gland Homeostasis in Hashimoto Thyroiditis: A Clinical Feasibility Parallel Trial with 6-Months Follow-Up

Hashimoto thyroiditis (HT) is a thyroid-specific autoimmune disorder, triggering hypothyroidism in a population with an adequate dietary intake. Despite the current conventional treatment focuses on the permanent replacement of levothyroxine (LT4) deficiency, it appears that thyroid autoimmunity remains the cause of persistent symptoms in patients with HT, even when they achieve to be euthyroid from a biochemical standpoint. Photobiomodulation (PBM) showed to be an effective therapy in the management of autoimmune diseases, but with limited evidence. Hence, our study was conducted to appraise the efficacy of PBM therapy with supplements in restoring thyroid gland homeostasis in patients with HT compared with supplements alone. Seventy-four female subjects aged between 20 and 50 years old were recruited and divided equally into two groups: PBM and supplements group (group 1); and supplements alone group (group 2). The PBM dosimetry and treatment protocols were as follows: wavelength, 820 nm; power output, 200 mW; continuous emission mode; irradiating time, 20 s per point; fluence, 32 J/cm2 per point; treatment frequency, twice a week (excluding weekends); and treatment duration, three consecutive weeks. Whereas, the supplements protocol for both groups was the same, as follows: subjects with a serum level of vitamin D3 <40 ng/dL, who received replacement according to their serum levels, and all the subjects had a daily intake of 100 µg of oral selenium. The biochemical (FT3, FT4, antiTPO and antiTG) and anthropometric measurements were evaluated. Our findings showed significant improvement in group 1 parameters (PBM+ supplements) compared with group 2 (supplements only) in terms of weight loss and reduction in the following parameters: BMI, hip and waist circumference, waist/hip ratio, TSH, antiTPO, antiTG and treatment dose of LT4 (p < 0.05). Our results, for the first time, demonstrated an efficacy of PBM delivered at a lower fluence with supplements in restoring thyroid function, anthropometric parameters and lifestyle factors in patients with HT. Hence, extensive studies with a longer follow-up period are warranted.

Antibacterial Evaluation of Zirconia Coated with Plasma-Based Graphene Oxide with Photothermal Properties

The alternative antibacterial treatment photothermal therapy (PTT) significantly affects oral microbiota inactivation. In this work, graphene with photothermal properties was coated on a zirconia surface using atmospheric pressure plasma, and then the antibacterial properties against oral bacteria were evaluated. For the graphene oxide coating on the zirconia specimens, an atmospheric pressure plasma generator (PGS-300, Expantech, Suwon, Republic of Korea) was used, and an Ar/CH₄ gas mixture was coated on a zirconia specimen at a power of 240 W and a rate of 10 L/min. In the physiological property test, the surface properties were evaluated by measuring the surface shape of the zirconia specimen coated with graphene oxide, as well as the chemical composition and contact angle of the surface. In the biological experiment, the degree of adhesion of Streptococcus mutans (S. mutans) and Porphyromonas gingivalis (P. gingivalis) was determined by crystal violet assay and live/dead staining. All statistical analyzes were performed using SPSS 21.0 (SPSS Inc., Chicago, IL, USA). The group in which the zirconia specimen coated with graphene oxide was irradiated with near-infrared rays demonstrated a significant reduction in the adhesion of S. mutans and P. gingivalis compared with the group not irradiated. The oral microbiota inactivation was reduced by the photothermal effect on the zirconia coated with graphene oxide, exhibiting photothermal properties.

Diode laser in management of loss of taste sensation in patients with post-COVID syndrome: a randomized clinical trial

OBJECTIVE

Loss of taste (ageusia) is a symptom observed following recovery from COVID-19 infection. The loss of taste and smell sensation may negatively affect patients' quality of life (QoL). The present study aimed to evaluate the effectiveness of the Diode Laser in managing loss of taste sensation in patients with post-COVID syndrome versus the placebo.

MATERIAL AND METHOD

The study sample was 36 patients who complained of persistent loss of taste sensation following COVID-19. The patients were randomly assigned to one of the two groups according to the received treatment: Group I (laser treatment) and Group II (light treatment), with each patient receiving a diode laser treatment or placebo from the same operator. Taste sensation was subjectively measured after treatment for four weeks.

RESULTS

The results demonstrated a significant difference between both groups regarding taste restoration after one month (p = 0.041), with Group II having a significantly higher percentage of cases 7 (38.9%) with partial taste restoration. In contrast, a significantly higher proportion of Group I 17 cases (94.4%) had complete taste restoration (p < 0.001).

CONCLUSION

The present study concluded that using a Diode laser 810 nm aided in a more rapid recovery from loss of taste dysfunction.

Comparative Study of the Efficacy of Low-Level Laser Therapy and Dexamethasone in Reducing the Severity of Post-Operative Inflammatory Response Following Surgical Extraction of Mandibular Third Molars

Objectives

To assesses the efficacy of low-level laser therapy (LLLT) over dexamethasone in reducing postoperative edema and trismus following surgical removal of mandibular third molars.

Study design

A single-center, parallel group, randomized, prospective, single-blind clinical trial on 50 patients between the age 18-40 years, requiring surgical extraction of mandibular third molars classified as mesioangular, class II and position B impactions, was selected for the study. The selected patients were randomly divided into two groups:Group 1, n  = 25, Soft Tissue Diode laser was applied intra-orally and extra-orally at the insertion of the masseter.Group 2, n  = 25, 8 mg of Dexamethasone was given intravenously preoperatively.Trismus and edema were calculated preoperatively and on the 1st and 5th postoperative day. The collected data were subjected to statistical analysis using student's t test.

Results

Trismus (4.61 ± 0.26 cm [p = 0.0001]) in the LLLT group was significantly less than the dexamethasone group (trismus: 3.82 ± 0.73 cm). Edema at different anatomic locations in the LLLT group was also significantly less than the dexamethasone group (Angle-tragus [p = 0.0008], angle-canthus [p = 0.0021], angle-ala [p = 0.0258], angle-commissure [p = 0.0168], angle-mentus [p = 0.0227]).

Conclusion

This study demonstrates that LLLT was beneficial in reduction in edema and trismus compared to dexamethasone following surgical extraction of third molars.

Extraoral low-level laser therapy can decrease pain but not edema and trismus after surgical extraction of impacted mandibular third molars: a randomized, placebo-controlled clinical trial

BACKGROUND

This study aimed to assess the effect of extraoral 940 nm low-level diode laser on pain, edema, and trismus following surgical extraction of impacted mandibular third molars.

MATERIALS AND METHODS

This split-mouth, randomized, placebo-controlled clinical trial evaluated 25 patients with bilaterally impacted mandibular third molars. One side of the jaw was randomly assigned to the laser and the other side to the control group. The laser quadrant received 940 nm diode laser irradiation (0.5 W, 10 J/cm², continuous-wave mode, 20 s) at three points in the master muscle in contact mode immediately after surgical extraction of third molar. The third molar in the placebo quadrant was extracted after 2 weeks by the same surgeon using the same standard approach. The pain score was measured at 2 and 7 days postoperatively using a visual analog scale (VAS). To assess trismus, the distance between the incisal edges of the upper and lower central incisors was measured in maximum opening. To assess edema, the distance between the tragus and chin point was measured before and immediately after surgery and after 2 and 7 days. Data were analyzed using t-test, ANOVA, and Bonferroni test.

RESULTS

The mean pain score in the first 7 days was significantly lower in the laser group (P < 0.05). Edema and trismus were the same in both groups (P > 0.05). Number of analgesics taken was significantly lower in the laser group (P < 0.05).

CONCLUSION

Single-session irradiation of 940 nm diode laser can effectively decrease pain following third molar extraction surgery.

TRIAL REGISTRATION NUMBER

IRCT20141209020258N91 on 29/12/2018.

Low-Level Laser Therapy in the Treatment of Autoimmune Thyroiditis

Introduction: Autoimmune thyroiditis (AIT) is an autoimmune disorder that is characterized by thyroid gland dysfunction. Low-level laser therapy (LLLT), as a safe and non-invasive intervention, has gained much attention in many clinical applications including pain relief, regenerative medicine, and autoimmune. Methods: In this review, we discuss the effect of LLLT on cellular responses and its application in the treatment of AIT. Such keywords as "low-level laser therapy", "photobiomodulation" and "autoimmune thyroiditis" were used to find studies related to laser therapy in AIT in Google Scholar, PubMed and Medline databases. Results: LLLT reduced thyroid gland inflammation and inhibited immune cell trafficking. LLLT modulated inflammatory responses and improved thyroid gland regeneration. Conclusion: Investigations indicated that besides current treatment strategies, LLLT could be a promising therapeutic approach for the treatment of AIT.

Treatment of partial injury of the calcaneus tendon with heterologous fibrin biopolymer and/or photobiomodulation in rats

The present study aimed to evaluate the new heterologous fibrin biopolymer associated, or not, with photobiomodulation therapy for application in tendon injuries, considered a serious and common orthopedic problem. Thus, 84 Rattus norvegicus had partial transection of the calcaneus tendon (PTCT) and were randomly divided into: control (CG); heterologous fibrin biopolymer (HFB); photobiomodulation (PBM); heterologous fibrin biopolymer + photobiomodulation (HFB + PBM). The animals received HFB immediately after PTCT, while PBM (660 nm, 40 mW, 0.23 J) started 24 h post injury and followed every 24 h for 7, 14, and 21 days. The results of the edema volume showed that after 24 h of PTCT, there was no statistical difference among the groups. After 7, 14, and 21 days, it was observed that the treatment groups were effective in reducing edema when compared to the control. The HFB had the highest edema volume reduction after 21 days of treatment. The treatment groups did not induce tissue necrosis or infections on the histopathological analysis. Tenocyte proliferation, granulation tissue, and collagen formation were observed in the PTCT area in the HFB and HFB + PBM groups, which culminated a better repair process when compared to the CG in the 3 experimental periods. Interestingly, the PBM group revealed, in histological analysis, major tendon injury after 7 days; however, in the periods of 14 and 21 days, the PBM had a better repair process compared to the CG. In the quantification of collagen, there was no statistical difference between the groups in the 3 experimental periods. The findings suggest that the HFB and PBM treatments, isolated or associated, were effective in reducing the volume of the edema, stimulating the repair process. However, the use of HFB alone was more effective in promoting the tendon repair process. Thus, the present study consolidates previous studies of tendon repair with this new HFB. Future clinical trials will be needed to validate this proposal.

Treatment with Light-Emitting Diodes of Wavelength 863 nm Delays DMBA/TPA-Induced Skin Tumor Formation and Decreases Proinflammatory Cytokine Levels in ICR Mice

The popularity of light/energy devices for cosmetic purposes (e.g., skin care) is increasing. However, the effects and underlying mechanisms remain poorly understood. Commencing in the 1960s, various studies have evaluated the beneficial effects of a light source on cells and tissues. The techniques evaluated include low-level light (laser) therapy and photobiomodulation (PBM). Most studies on PBM used red light sources, but, recently, many studies have employed near-infrared light sources including those of wavelength 800 nm. Here, we used a light-emitting diode (LED) array with a wavelength of 863 nm to treat DMBA/TPA-induced mouse skin tumors; treatment with the array delayed tumor development and reduced the levels of systemic inflammatory cytokines. These results suggest that light therapy could be beneficial. However, the effects were small. Further studies on different skin tumors using an optimized LED setup are required. Combination therapies (conventional methods and an LED array) may be useful.

Treatment of carpal tunnel syndrome by low-level laser therapy versus corticosteroid injection: a randomized, prospective clinical study

To compare the effects of low level laser therapy (LLLT) and corticosteroid injection in patients with moderate carpal tunnel syndrome (CTS). Eighty-seven patients (143 wrists) with moderate CTS were randomized to the corticosteroid or LLLT groups. 40 mg of triamcinolone acetate solution was applied to carpal tunnel of 44 patients (74 wrist). LLLT was applied to 43 patients (70 wrist) five times a week, for a total of 15 sessions (fluence of 6 j/cm² for 1 min per point at a wavelength of 830 nm). Outcome measures were numbness and pain, QuickDASH questionnaire, grasping tests, Tinel and Phalen tests, electrophysiological tests and MRI evaluations, which were tested at the baseline and 1st and 6th months after the treatment. Eighty patients (133 wrists) completed the study at the end of 6 months. VAS and Quick DASH scores were better in the corticosteroid group in the 1st month, but there were no significant differences between groups in the 6th month. Phalen and Tinel tests, strength tests, and motor distal latency improved significantly and similarly in both groups at the 1st and 6th months. Sensory distal latency and sensory nerve conduction velocity showed significant improvements in the 1st and 6th months only in the corticosteroid group. In both groups, median nerve intensity rate and palmary spring rate improved significantly after the treatment. Based on this study, corticosteroid injection and LLLT groups showed statistically significant difference at the 1st month (short-term), whereas there was no significant difference at the 6th month (intermediate-term).

Photobiomodulation effect in tumoral necrosis factor-alpha(TNF-α) on the viability of random skin flap in rats

The aim of this study was to investigate the effect of red laser (660 nm) photobiomodulation (PBM) with different energies on tumor necrosis factor-alpha(TNF-α) expression for random skin flap viability in rats. Twenty-four Wistar rats were divided into three groups: sham group (SG), PBM laser group with an energy dose of 0.29 J (0.29G), and PBM laser group with an energy dose of 7.30 J (7.30G). A cranially based dorsal skin flap measuring 10 × 4 cm was raised and a plastic barrier was placed between the flap and its bed. PBM was applied in 3 timepoints: in the immediate postoperative period, in the 1^st and in the 2^nd postoperative days; the animals were euthanized on the 7^th postoperative day. The assessments included: TNF-α expression of 3 different flap areas (proximal, medial and distal), by immunohistochemistry; percentage of skin flap necrosis area, by the paper template method. The statistical analysis was performed through the Kruskal-Wallis and Mann-Whitney tests, the level of significance adopted was 5% (p < 0.05). TNF-α expression was significantly lower for 7.30G in the proximal area, reduced for SG in the medial point, and larger for 7.30G in the distal area. The percentage of flap necrosis area was significantly reduced for 7.30G. Higher energy doses are more efficacious than lower energy doses for modulating TNF-α expression. PBM with an energy dose of 7.30 J was effective in reducing the expression of TNF-α and increase skin flap viability.

Effect of Photobiomodulation on Periodontal Ligament Cells Under Inflamed and Nutrient-Deficient Conditions Simulating Damaged Cells of Avulsed Teeth: An In Vitro Study

Background: The prognosis of replanted teeth is depended on the vitality of periodontal ligament cells residual on the root surface. Photobiomodulation has photobiological effects that can promote cell vitality. The study aimed to explore the effect of photobiomodulation on the periodontal ligament cells under inflamed or starved conditions mimicking clinically damaged periodontal ligament cells of avulsed teeth and provide the adjuvant procedure for tooth replantation. Materials and methods: Normal, starved, or inflamed periodontal ligament cells were irradiated with an 808 nm laser at densities of 0, 1, 3, 5, or 10 J/cm². The cell counting kit-8 (CCK-8) assay and scratch test were applied to determine the effects on the proliferation and migration of cells. Anti-inflammatory effects were assessed according to the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) measured by reverse-transcription polymerase chain reaction. Osteogenic capacity was evaluated by alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin Red S staining, and ALP and osteocalcin (OCN) mRNA expression. Results: The CCK-8 assay and scratch test demonstrated that the 808 nm laser significantly promoted proliferation and migration of normal condition periodontal ligament cells at a density of 3 J/cm² versus 5 J/cm² under the starved and inflamed conditions. Moreover, the 808 nm laser had anti-inflammatory effects and promoted osteogenesis of periodontal ligament cells at 3 J/cm² under normal conditions, while photobiomodulation at 5 J/cm² upregulated the osteogenesis of periodontal ligament cells under starved and inflamed conditions. Conclusions: The photobiomodulation of 808 nm laser reduced inflammation and improved the proliferation, migration, and osteogenesis of normal, starved, and inflamed periodontal ligament cells. These effects required a higher energy density under starved or inflamed conditions compared with normal conditions. The photobiomodulation of 808 nm has a potential application in root surface treatment for replanted teeth.

Photobiomodulation inhibits inflammation in the temporomandibular joint of rats

Photobiomodulation (PBM) has been applied as a non-invasive technique for treating temporomandibular joint symptoms, especially on painful condition's relief, however the anti-inflammatory mechanism underlying the effect of PBM remains uncertain. This study aims to evaluate the mechanisms of action of PBM (808 nm) in a carrageenan-induced inflammation on temporomandibular joint (TMJ) of rats. In this study male Wistar rats were pre-treated with irradiation of a low-power diode laser for 15 s on TMJ (infra-red 808 nm, 100 mW, 50 J/cm² and 1.5 J) 15 min prior an injection in the temporomandibular joint of carrageenan (100 μg/TMJ). 1 h after the TMJ treatments, the rats were terminally anesthetized for joint cavity wash and periarticular tissues collect. Samples analysis demonstrated that PBM inhibit leukocytes chemotaxis in the TMJ and significantly reduces amounts of TNF-α, IL-1β and CINC-1. In addition, Western blotting analysis demonstrated that PBM significantly decreased the protein levels of P2X3 and P2X7 receptors in the periarticular tissues. On the other hand, PBM was able to increase protein level of IL-10 (anti-inflammatory cytokine). In summary, it is possible to suggest that PBM inhibit inflammatory chemotaxis, modulation the balance of the pro- and anti-inflammatory characteristics of inflammatory cells.

Use of low-level laser therapy to reduce postoperative pain, edema, and trismus following third molar surgery: A systematic review and meta-analysis

This Systematic Review and Meta-analysis was conducted with the following PICOS question: patients undergoing third molar surgery (P) can benefit from low-intensity laser therapy (I) as compared to other postoperative management (C) to reduce pain, edema, and trismus (O), evaluated in previous randomized clinical trials (S). Databases used were PubMed, SCOPUS, Web of Science, and Biblioteca Virtual em Saúde, screening for studies published between 2015 and 2020. The meta-analysis was based on the standardized mean difference (SMD), under a 95% confidence interval (CI). 246 studies were initially included, and after the screening of data, 10 studies were selected for the final sample. The qualitative analysis resulted in favorable results for pain and edema management in most studies, whereas trismus remained controversial. Meta-analysis resulted in (SMD, -0.53; 95% CI, -0.82,-0.24), (SMD, -0.60; 95% CI, -0.81,-0.39), and (SMD, -0.62; 95% CI, -2.63, 1.39) for pain, edema, and trismus, respectively, indicating statistical success on pain and edema reduction, but not for trismus. LLLT can act on reducing postoperative pain and edema following third molar surgery, whereas, trismus remains not significantly changed.

Comparison of effects of low-level laser therapy and extracorporeal shock wave therapy in calcaneal spur treatment: A prospective, randomized, clinical study

Objectives

In this study, we aimed to evaluate and compare the efficacy of low-level laser therapy (LLLT) and extracorporeal shock wave therapy (ESWT) in the treatment of calcaneal spurs.

Patients and methods

A total of 62 patients (14 males, 48 females; mean age: 47.6±11.7 years; range, 18 to 70 years) who were diagnosed with calcaneal spurs based on clinical examination and plain radiography between April 2019 and September 2019 were included in this study. A total of 15 sessions of plantar fascia gastroc-soleus stretching exercises and cold pack treatments were given to both groups. The LLLT (904 nm wavelength, 3,000 Hz, 8 J/cm2 dose to the painful heel area and insertion of the plantar fascia on the medial calcaneal area, five points for a total of 5 min for three weeks) was applied to the first group (n=31), whereas ESWT (10 Hz, 2,000 shock waves with a 2.5 bar pressure into the areas of the painful heel, insertion of the plantar fascia on the medial calcaneal area) was applied the second group (n=31). All patients were evaluated using the Visual Analog Scale (VAS) and Foot Function Index (FFI) before and after treatment.

Results

In both groups, the median VAS and FFI scores after treatment showed a significant improvement, compared to pre-treatment scores (p=0.001). There was no significant difference between the groups in terms of the median post-treatment VAS scores (p>0.05). In the ESWT group, the median FFI pain and total scores after treatment were significantly lower than in the LLLT group (p=0.033). The change in the median FFI pain and total scores were significantly higher in the ESWT group (p=0.046).

Conclusion

Both treatment modalities are effective and not superior to each other in terms of disability and activity limitation reduction, although a greater improvement in the FFI pain and total scores can be achieved with the ESWT. Based on these findings, we recommend both non-invasive treatment methods to be used in the treatment of calcaneal spurs in the clinical practice.

Oxidative stress is involved in LLLT mechanism of action on skin healing in rats

The skin injury healing process involves the main phases of homoeostasis, inflammation, proliferation, and remodeling. The present study aimed to analyze the effects of low-level laser therapy (LLLT) on hematological dynamics, oxidative stress markers, and its relation with tissue healing following skin injury. Wistar rats were divided into control, sham, skin injury, and skin injury LLLT. The biochemical and morphological analyses were performed in the inflammatory (1 and 3 days) and regenerative phases (7, 14, and 21 days) following injury. The skin injury was performed in the dorsal region, between the intrascapular lines, using a surgical punch. LLLT (Al-Ga-In-P, λ=660 nm, energy density of 20 J/cm², 30 mW power, and a time of 40 s) was applied at the area immediately after injury and on every following day according to the experimental subgroups. LLLT maintained hematocrit and hemoglobin levels until the 3rd day of treatment. Surprisingly, LLLT increased total leukocytes levels compared to control until the 3rd day. The effects of LLLT on mitochondrial activity were demonstrated by the significant increase in MTT levels in both inflammatory and regenerative phases (from the 1st to the 7th day), but only when associated with skin injury. The results indicated that LLLT modulated the inflammatory response intensity and accelerated skin tissue healing by a mechanism that involved oxidative damage reduction mostly at early stages of skin healing (inflammatory phase).

Effects of Low Level Laser Therapy (LLLT) on Serum Values of Interleukin 6 (IL-6) in Patients with Periodontitis and Type 2 Diabetes Mellitus (T2DM)

BACKGROUND

In patients with T2DM, the therapeutic effects of conservative treatment are quite limited, and there is a need for additional therapeutic procedures to achieve the desired satisfactory and solid effect. Low-level laser therapy (LLLT) has an anti-inflammatory effect, and is used to heal lesions. This mechanism is realized through inhibition of lipopolysaccharides (LPS), so it can be used in the treatment of periodontal disease in patients with diabetes.

OBJECTIVE

The aim of this study is to assess the effect of level laser therapy (LLLT) on serum IL-6 values in patients with periodontitis and T2DM.

METHODS

Patients at age between 35-60 years old, with chronic periodontitis (CH) where the clinical loss of attachment (CAL) was ≥4 mm therefore covering at least 50 % of affected teeth. In this study we included 80 patients, divided into two groups: 40 patients with type 2 diabetes mellitus (2TDM) treated with conservative periodontal treatment supplemented with laser therapy (LLLT), group A, and 40 patients with 2TDM, conservatively treated without LLLT. therapy i.e. group B. The laser light was applied to the gingiva in separate quadrants in 5 sessions for the next five days in a row. Blood samples were taken from all subjects at the first treatment, then in 6 weeks and 3 months after treatment, and interleukin 6 (IL-6) levels were measured. The blood samples in the test tubes remained for about 30 minutes and were then distributed in a biochemical laboratory, where they were centrifuged at 6,000 rpm for 10 minutes. The serum was separated from the test tube and transferred to the eppendorph. All serum samples were stored at -80 ° C until complete analysis and determination of IL-6, according to the standardized methodology.

RESULTS

In group A, on the first examination serum IL-6 levels varies in the interval 11.54 ± 1.11 pg / mL, after 6 weeks of therapy the values range between 11.26 ± 0.77 pg / mL, and after 3 months of therapy levels oscillate at intervals of 11.02 ± 0.67 pg / mL. In group B the findings are similar. At the first examination, the serum IL-6 values were 11.56 ± 0.81 pg / mL, after 6 weeks of therapy ranged from 11.59 ± 0.71 pg / mL, and after 3 months of therapy levels were recorded at intervals. 11.41 ± 0.78 pg /mL. The serum IL-6 value after 6 weeks of therapy in patients in group B for Z = -2.04 and p <0.05 (p = 0.04) was significantly higher than in patients in group A, while after 3 months of therapy in patients in group B for Z = -2.42 and p <0.05 (p = 0.02) is significantly higher than the value in patients in group A.

CONCLUSION

LLLT resulted in significantly reduced serum IL-6 values in patients with periodontitis and T2DM after 6 weeks and 3 months of therapy in which conservative treatment was supplemented with LLLT.

Photobiomodulation: A review of the molecular evidence for low level light therapy

Light energy is harnessed for therapeutic use in a number of ways, most recently by way of photobiomodulation (PBM). This phenomenon is a cascade of physiological events induced by the nonthermal exposure of tissue to light at the near infrared end of the visible spectrum. Therapeutic PBM has become a highly commercialized interest, marketed for everything from facial rejuvenation to fat loss, and diode-based devices are popular in both the clinic setting and for use at home. The lack of regulatory standards makes it difficult to draw clear conclusions about efficacy and safety but it is crucial that we understand the theoretical basis for PBM, so that we can engage in an honest dialogue with our patients and design better clinical studies to put claims of efficacy to the test. This article presents a summary of the science of PBM and examines the differences between laser light, on which much of the preclinical evidence is based and light from diodes, which are typically used in a clinical setting.

Laser Analgesia Associated with Restorative Dental Care: A Systematic Review of the Rationale, Techniques, and Energy Dose Considerations

It is a common experience amongst laser dentists and patients that mid-IR wavelength application in cavity preparation may be achieved without causing any associated pain. The erbium family of lasers (Er,Cr:YSGG 2780 nm and Er:YAG 2940 nm) are frequently used without employing injectable local anesthesia as an adjunct: the phenomenon arising from the application of these devices is known as laser analgesia. This review seeks to apply a systematic approach to the examination of appropriate published studies but also to highlight the need for much more structured clinical investigations that consolidate photonic dose and methodology. A search of published data using PRISMA criteria was carried out to examine clinical trials into laser analgesia in conjunction with restorative dentistry, applying inclusion and exclusion criteria. From this, 10 published articles were selected for analysis. Suitability assessment was carried out, using a modified Cochrane risk of bias methodology. In 8/10 of the included studies, laser-induced analgesia is claimed to be better and effective, while in 2/10 of the studies, no difference was exhibited compared to the control group. Statistical analysis of three split mouth studies concluded that only one of these investigations reviewed demonstrated a significant analgesic effect for laser treatment while the other two did not support this observation. From this data, it is inconclusive to assess the predictability of laser analgesia in cavity preparation. A possible rationale and laser operating parametry has been discussed. Successful implementation of this treatment modality remains technique sensitive and subject to further investigation.

Comparison of low-level laser treatment and extracorporeal shock wave therapy in subacromial impingement syndrome: a randomized, prospective clinical study

The aim of this study was to compare the efficacy of low-level laser treatment (LLLT) and extracorporeal shock wave therapy (ESWT) in the treatment of subacromial impingement syndrome (SIS). Seventy-one patients with subacromial impingement were randomly assigned to LLLT (n = 37) and ESWT (n = 34) groups. The patients received a total of 15 sessions of LLLT or once a week for 3 sessions of ESWT. All patients, before treatment, at the end of treatment, and 3 months after treatment, were evaluated with range of motion (ROM), visual analogue pain scale (VAS pain), Shoulder Pain and Disability Index (SPADI), Beck Depression and Anxiety Inventories, the Short Form Health Survey (SF-36), and Pittsburgh Sleep Quality Index (PSQI). In both groups, there was a significant improvement in all outcome measures (p < 0.05) except the mental health score in the LLLT group. ESWT group showed more improvements in terms of SPADI disability and total scores, PSQI, and physical-mental health scores at the end of treatment (p < 0.05). The improvement in VAS pain day and SPADI scores at the third month was significantly more evident in the ESWT group (p < 0.05). Both LLLT and ESWT treatments are effective in the treatment of SIS in the short-medium term and can be used in clinical practice. Future larger prospective clinical trials are needed to investigate the long-term efficacy and optimal treatment protocol of LLLT and ESWT in SIS.

Photobiomodulation and Stem Cell Therapy for Temporomandibular Joint Disc Disorders

Background: Temporomandibular disorder (TMD) refers to a group of disorders affecting the temporomandibular joint (TMJ) and its related muscles. The two commonly used treatment modalities for TMD are occlusal splint therapy and relaxation therapy. Neither comprises definitive treatment. Objective: The objective of this review was to report updated information on photobiomodulation and stem cells, as an alternative treatment for the degenerative TMJ disc as a part of TMJ disorders. Materials and methods: With only a few research studies reported till date, this review also proposes the mechanism of laser irradiation on inflammatory mediators to treat TMD. Results: Photobiomodulation of stem cells with and without scaffolds could be used indirectly or directly as modulation of degenerative changes of the TMJ disc. Conclusions: The need for a distinct shift of the research margin in this field of dentistry is evident, specifically regarding the application of photobiomodulation and stem cells for tissue engineering of the TMJ disc.

High-Frequency Near-Infrared Diode Laser Irradiation Attenuates IL-1β-Induced Expression of Inflammatory Cytokines and Matrix Metalloproteinases in Human Primary Chondrocytes

High-frequency near-infrared diode laser provides a high-peak output, low-heat accumulation, and efficient biostimulation. Although these characteristics are considered suitable for osteoarthritis (OA) treatment, the effect of high-frequency near-infrared diode laser irradiation in in vitro or in vivo OA models has not yet been reported. Therefore, we aimed to assess the biological effects of high-frequency near-infrared diode laser irradiation on IL-1β-induced chondrocyte inflammation in an in vitro OA model. Normal Human Articular Chondrocyte-Knee (NHAC-Kn) cells were stimulated with human recombinant IL-1β and irradiated with a high-frequency near-infrared diode laser (910 nm, 4 or 8 J/cm²). The mRNA and protein expression of relevant inflammation- and cartilage destruction-related proteins was analyzed. Interleukin (IL) -1β treatment significantly increased the mRNA levels of IL-1β, IL-6, tumor necrosis factor (TNF) -α, matrix metalloproteinases (MMP) -1, MMP-3, and MMP-13. High-frequency near-infrared diode laser irradiation significantly reduced the IL-1β-induced expression of IL-1β, IL-6, TNF-α, MMP-1, and MMP-3. Similarly, high-frequency near-infrared diode laser irradiation decreased the IL-1β-induced increase in protein expression and secreted levels of MMP-1 and MMP-3. These results highlight the therapeutic potential of high-frequency near-infrared diode laser irradiation in OA.

Impact of Photobiomodulation on T3/T4 Ratio and Quality of Life in Hashimoto Thyroiditis

Objective and background: Hashimoto's thyroiditis (HT) is both a B cell- and T cell-mediated, organ-specific autoimmune disease. No current treatment for underlying pathological mechanisms is available for HT and once diagnosed it requires long-term levothyroxine (LT₄) treatment in most patients. The aim of our study was to evaluate the effects of photobiomodulation (PBM) on HT patients regarding thyroid functions, thyroid autoantibody levels, and decrease in hormone replacement needs. Methods: A total of 350 patients, who were diagnosed with Hashimoto`s thyroiditis, were included in our study. Patients were classified into two groups. Group 1 (n = 210) received PBM and dietary supplementation such as vitamin D, iron, and selenium. Group 2 (n = 140) received dietary supplements only. Patients' needs for LT₄ replacement levels, triiodothyronine (T3), thyroxine (T4), and TSH levels, T3/T4 ratio, and thyroid autoantibody levels were evaluated. Results: As we compare both groups, the increase in T3 levels and T3/T4 ratio was markedly superior in Group 1 (p = 0.0001). The decrease in thyroid peroxidase antibody (TPO Ab) levels was also significantly different between both groups (p = 0.0001). Hormone replacement needs were also significantly decreased in Group 1 compared with Group 2 (p = 0.03). Low-level laser therapy (LLLT) is 70 times more effective in increasing T3/T4 ratio (p = 0.001) and 15 times more effective in decreasing levothyroxine dosage. Conclusions: Our results are encouraging and PBM seems to be very effective in increasing T3/T4 ratio and decreasing TPO Ab levels and weekly dosages of LT₄ replacement therapy. Anti-inflammatory properties of PBM are greatly responsible for these changes and PBM causes major improvements in HT-related symptoms of the patient.

Can Photobiomodulation Therapy Be an Alternative to Methylprednisolone in Reducing Pain, Swelling, and Trismus After Removal of Impacted Third Molars?

Background and objective: Studies investigating an alternative to corticosteroids in terms of potential side effects after surgical removal of impacted third molars are still ongoing. Accordingly, the present randomized single-blind study aimed to compare the efficacy of photobiomodulation therapy (PBMT) and methylprednisolone on pain, edema, and trismus after surgical removal of impacted third molars. Methods: The study included 30 healthy patients with bilaterally impacted lower third molars. The side (right or left molar) that would be extracted at first and the treatment (PBMT or corticosteroid) that would be applied to this side were decided by tossing a coin. The time interval between two surgical operations was at least 3 weeks. In the laser group, immediately after the surgical procedure, PBMT was applied extraorally to the insertion point of the masseter muscle for 60 sec with an output power of 0.3 W and an energy density of 6 J/cm² and then repeated on postoperative days 1 and 2. In the corticosteroid group, 40 mg/2 mL methylprednisolone sodium succinate was injected postoperatively into the masseter muscle with the intrabuccal approach. On postoperative day 1, methylprednisolone injection (20 mg/1 mL) was repeated. Pain was evaluated using the visual analog scale on postoperative days 1, 2, and 7. Edema (in mm) and trismus (in mm) were evaluated preoperatively and on postoperative days 2 and 7. Results: There were no significant differences between the PBMT and methylprednisolone administration in terms of postoperative pain, edema, and trismus. Conclusions: Within the limits of the present study, PBMT was considered an alternative and a useful method for controlling inflammatory complications following impacted wisdom tooth surgery as it exhibited similar clinical efficacy to that of methylprednisolone.

Effectiveness of Low-Level Laser Therapy with a 915 Nm Wavelength Diode Laser on the Healing of Intraoral Mucosal Wound: An Animal Study and a Double-Blind Randomized Clinical Trial

Background and objectives: Diode laser has been the most popular low-level laser therapy (LLLT) technique in dentistry due to its good tissue penetration, lower financial costs, small size for portable application, and convenience to use. A series of recent studies with 940 nm or 980 nm lasers demonstrated that LLLT showed positive effects after third molar extraction or periodontal flap surgery. However, the effects of LLLT on intraoral mucosal wound healing after surgical incision have not yet been determined in human clinical study. Materials and Methods: The present study was performed to determine the efficacy and safety of 915 nm wavelength low-level laser therapy (LLLT) in mucosal wound healing. A total of 108 Sprague-Dawley rats were used. They were divided into three groups: Abrasive wound group, immediate LLLT once group, and daily LLLT group. As a clinical study, a total of 16 patients with split-mouth design subjected to bilateral mandibular third molar extraction were allocated into the LLLT group and placebo group. The process of LLLT was performed on postoperative days 0, 1, and 7, and parameters related to wound healing were analyzed on days 1, 7, and 14. Results: Repeated laser irradiation promoted mucosal wound healing of the rats. In the clinical study, although there were no significant statistical differences between the LLLT and placebo groups in all inflammatory parameters, the early stage mucosal healing tendency of wound dehiscence was higher in the LLLT group than in the placebo group clinically on postoperative day 1. Conclusions: The present results showed that 915 nm LLLT could be applied safely as an auxiliary therapy for mucosal wound healing.

Effect of intracanal diode laser application and low-level laser therapy on CGRP change

The aim of this study was to investigate the effect of a placebo, intracanal diode laser application, and low-level laser therapy (LLLT) on the change of the total amount of calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid (GCF) (split-mouth study design). GCF sampling was performed on a contralateral tooth and experimental tooth (root canal-treated tooth) of thirty-nine patients. The patients were divided into three groups (n = 13), as follows: placebo (mock laser application), intracanal laser application, and LLLT. GCF sampling was repeated at the same sites (experimental and control teeth) one week after root canal treatment. The data were analyzed using the Pearson's correlation analysis and the independent-samples t-tests (p=0.05). In the placebo group, the total CGRP level changes in the GCF before and after treatment was significantly higher for experimental teeth than for control teeth (p<0.05). However, there was no significant difference between experimental and control teeth in the intracanal laser application and LLLT groups (p > 0.05). Intracanal laser application and low-level laser therapy have immunomodulation effects linked to the modulation of the total amount of CGRP in the GCF.

Is there a measure for low power laser dose?

Low power lasers have been used successfully for treatment of many diseases in soft and bone tissues. Basic and clinical researches have developed quickly being the scientific basis to therapeutic protocols based on these lasers. However, there are difficulties to compare experimental and clinical results obtained from different researchers because a complicated and intricate list of physical and biological parameters should be checked before the irradiation procedures as well as part of these parameters are omitted or inaccurately reported. This review focuses on the physical and biological parameters proposed to make experimental and clinical protocols accurate and reproducible as well as suggests dose parameters based on biological effects induced by low power lasers. A variety of parameters are reported by different authors and the number of parameter suggested could overcome three dozens. Thus, laser dose and laser dose equivalent are defined based on laser-induced biological effects and suggested as simplified dose parameters for low power lasers. These parameters could simplify and be useful to researchers and clinicians, permitting comparisons and decreasing mistakes and inaccuracies when laser-induced effects are evaluated and compared with those obtained in previous studies. The laser dose and laser dose equivalent could contribute significantly to improve accuracy, effectiveness, and safety of clinical protocols based on low power lasers.

Free gingival graft adjunct with low-level laser therapy: a randomized placebo-controlled parallel group study

OBJECTIVES

This study aimed to evaluate the effect of low-level laser therapy (LLLT) in terms of enhancing wound healing, reducing free gingival graft (FGG) shrinkage and postoperative pain.

MATERIALS AND METHODS

Thirty patients were randomly assigned to receive either FGG + LLLT (test, n = 15) or FGG + plasebo LLLT (control, n = 15). In the test group, a diode laser (810 nm, 0.1 W, energy density 6 J/cm²) was applied immediately after surgery and 1, 3, 7, and 14 days later. Measurements of the graft surface areas of the groups were made with an image-analyzing software at baseline and first, third, and sixth months. Complete wound epithelialization and visual analogue scale (VAS) for pain score were evaluated after surgery.

RESULTS

Shrinkage of the graft was statistically higher in the control than the test group at third and sixth months (p < 0.05). In terms of epithelization of the graft area, the test and control groups did not show any significant difference during the 28-day period (p > 0.05). Besides this, statistically significant differences were observed for VAS pain score and the number of analgesic used (p < 0.05).

CONCLUSIONS

The use of an 810-nm diode laser provided additional benefits to FGG in terms of less shrinkage of the graft dimensions and postoperative pain.

CLINICAL RELEVANCE

Low-level laser therapy reduced the shrinkage of free gingival graft's surface area after 6 months and enhanced postoperative pain relief.

Anti-inflammatory effects of low-level laser therapy on human periodontal ligament cells: in vitro study

Periodontal disease is a chronic inflammatory disease that is commonly treated with surgical and nonsurgical techniques. However, both approaches have limitations. Low-level laser therapy (LLLT) has been widely applied in reducing inflammatory reactions, and research indicates that LLLT induces an anti-inflammatory effect that may enhance periodontal disease therapy. The purpose of this study was to investigate the anti-inflammatory effect of LLLT on human periodontal ligament cells (hPDLCs) in an inflammatory environment and aimed to determine the possible mechanism of action. Cells were cultured and treated with or without lipopolysaccharide (LPS) from Porphryromonas gingivalis or Escherichia coli, followed by irradiation with a gallium-aluminum-arsenide (GaAlAs) laser (660 nm) at an energy density of 8 J/cm². Quantitative real-time polymerase chain reactions were used to assess the expression of pro-inflammatory genes, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8. The dual-luciferase reporter assay was used to examine nuclear factor-κB (NF-κB) transcriptional activity. An enzyme-linked immunosorbent assay was used to monitor the concentration of intracellular cyclic adenosine monophosphate (cAMP). Both LPS treatments significantly induced the mRNA expression of pro-inflammatory cytokines. However, LLLT inhibited the LPS-induced pro-inflammatory cytokine expression and elevated intracellular levels of cAMP. The LLLT inhibitory effect may function by downregulating NF-κB transcriptional activity and by increasing the intracellular levels of cAMP. LLLT might inhibit LPS-induced inflammation in hPDLCs through cAMP/NF-κB regulation. These results should be further studied to improve periodontal therapy.

Low level laser (LLL) attenuate LPS-induced inflammatory responses in mesenchymal stem cells via the suppression of NF-κB signaling pathway in vitro

Background

Considering promising results in animal models and patients, therapeutic use of MSCs for immune disease is likely to undergo continued evaluation. Low-lever laser (LLL) has been widely applied to retard the inflammatory reaction. LLL treatment can potentially be applied in anti-inflammatory therapy followed by stem cell therapy.

Aim of the study

The purpose of this study was to investigate the effect of LLL (660 nm) on the inflammatory reaction induced by LPS in human adipose derived mesenchymal stem cells (hADSCs) and pertinent mechanism.

Materials and methods

Anti-inflammatory activity of LLL was investigated by LPS-induced mesenchymal stem cells. The production and expression of pro-inflammatory cytokines were evaluated by ELISA kits and RT-qPCR. Nuclear translocation of NF-κB was indicated by immunofluorescent staining. Phosphorylation status of NF-κB p65 and IκBα were illustrated by western blot assay. ROS generation was measured with CM-H2DCFDA, and NO secretion was determined by DAF-FM. We studied surface expression of lymphocyte activation markers when Purified peripheral blood mononuclear cell (PBMC) were activated by phytohaemagglutinin (PHA) in the presence of 3 types of treated MSCs.

Results

LLL reduced the secretion of IL-1β, IL-6, IL8, ROS and NO in LPS treated MSCs. Immunofluorescent assay demonstrated the nuclear translocation decrease of NF-κB in LLL treated LPS induced MSCs. Western blot analysis also suggested that LLL suppressed NF-κB activation via regulating the phosphorylation of p65 and IκBα. MSC significantly reduced the expression of activation markers CD25 and CD69 on PHA-stimulated lymphocytes.

Conclusion

The results indicate that LLL suppressed the activation of NF-κB signaling pathway in LPS treated MSCs through inhibiting phosphorylation of p65 and IκBα, which results in good anti-inflammatory effect. In addition, LLL attenuated activation-associated markers CD25 and CD69 in co-cultures of PBMC and 3 types of treated MSCs.

Efficacy of low-level laser therapy in carpal tunnel syndrome management: a systematic review and meta-analysis

We performed this meta-analysis to investigate the efficacy of low-level laser therapy (LLLT), a physiotherapy modality with anti-inflammatory and analgesic effects, in the management of mild-to-moderate carpal tunnel syndrome (CTS). We searched PubMed, Web of Knowledge, Scopus, Cochrane Central, and Virtual Health Library for randomized controlled trials (RCTs) that compared the effects of LLLT with or without splinting versus placebo on functional and electromyographic outcomes in CTS. All outcomes were pooled as mean differences (MD) under the inverse variance or random effects model, using the statistical add-in (MetaXL, version 5.0). Eight RCTs (473 patients/631 wrists) were eligible for the final analysis. The overall effect estimates did not favor LLLT therapy group over placebo in all primary outcomes: visual analogue scale (MD -1.11, 95% CI [-2.58, 0.35]), symptom severity scale score (MD -1.41, 95% CI [-5.12, 2.29]), and functional status scale score (MD -1.33, 95% CI [-3.27, 0.61]). However, LLLT was superior to placebo in terms of grip strength (MD 2.19, 95% CI [1.63, 2.76]) and inferior to placebo in terms of sensory nerve action potential (MD -2.74, 95% CI [-3.66, -1.82]). Laser therapy is superior to placebo in terms of improving the grip strength; however, no significant difference was found between both groups in terms of functional status improvement, pain reduction, or motor electrodiagnostic evaluations. Further high-quality trials with longer follow-up periods are required to establish the efficacy of LLLT for CTS treatment.

Low-Level Laser Irradiation Precondition for Cardiac Regenerative Therapy

OBJECTIVE

The purpose of this article was to review the molecular mechanisms of low-level laser irradiation (LLLI) preconditioning for heart cell therapy.

BACKGROUND DATA

Stem cell transplantation appears to offer a better alternative to cardiac regenerative therapy. Previous studies have confirmed that the application of LLLI plays a positive role in regulating stem cell proliferation and in remodeling the hostile milieu of infarcted myocardium. Greater understanding of LLLI's underlying mechanisms would be helpful in translating cell transplantation therapy into the clinic.

METHODS

Studies investigating LLLI preconditioning for cardiac regenerative therapy published up to 2015 were retrieved from library sources and Pubmed databases.

RESULTS

LLLI preconditioning stimulates proliferation and differentiation of stem cells through activation of cell proliferation signaling pathways and alteration of microRNA expression. It also could stimulate paracrine secretion of stem cells and alter cardiac cytokine expression in infarcted myocardium.

CONCLUSIONS

LLLI preconditioning provides a promising approach to maximize the efficacy of cardiac cell-based therapy. Although many studies have reported possible molecular mechanisms involved in LLLI preconditioning, the exact mechanisms are still not clearly understood.

Wound healing efficacy of a 660-nm diode laser in a rat incisional wound model

This study aimed to elucidate the optimum usage parameters of low reactive-level laser therapy (LLLT) in a rat incisional wound model. In Sprague-Dawley rats, surgical wounds of 15-mm length were made in the dorsal thoracic region. They were divided into groups to receive 660-nm diode laser irradiation 24 h after surgery at an energy density of 0 (control), 1, 5, or 10 J/cm². Tissue sections collected on postoperative day 3 were stained with hematoxylin-eosin and an antibody for ED1 to determine the number of macrophages around the wound. Samples collected on day 7 were stained with hematoxylin-eosin and observed via polarized light microscopy to measure the area occupied by collagen fibers around the wound; day 7 skin specimens were also subjected to mechanical testing to evaluate tensile strength. On postoperative day 3, the numbers of macrophages around the wound were significantly lower in the groups receiving 1 and 5 J/cm² irradiation, compared to the control and 10 J/cm² irradiation groups (p < 0.01). The area occupied by collagen fibers in day 7 was largest in 5 J/cm² group, followed by 1 J/cm² group, although this difference was not significant. The day 7 tensile test demonstrated significantly greater rupture strength in healing tissues from 1 and 5 J/cm² irradiation groups, compared to the control group (p < 0.05). Thus, LLLT with a 660-nm diode laser with energy density of 1 and 5 J/cm² enhanced wound healing in a rat incisional wound model. However, a higher radiation energy density yielded no significant enhancement.

Low-level laser therapy: Case-control study in dogs with sterile pyogranulomatous pododermatitis

AIM

Low-level laser therapy (LLLT) is a therapeutic photobiostimulation with properties in reducing swelling, inflammation, and promoting tissue healing. The objective of this pilot study was to evaluate LLLT in sterile pyogranulomatous pododermatitis in five dogs.

MATERIALS AND METHODS

In each dog, one lesion was designated as the control (treated with a 0.0584% hydrocortisone aceponate spray), and one or more other lesions were treated with a gallium aluminum arsenide-laser, daily for 5 days. Lesions were scored before treatment (D0), at the end (D4), 16 days after the last laser treatment (D20), and after 2 months (D65).

RESULTS

Comparing the treated lesion group with the control lesion group, the clinical score was similar at D0, whereas there was a statistically significant difference at D4 and D20; in the treated group over time, there was a statistically significant improvement between D0, D4, and D20. Lesion recurrence was absent in more than 50% of the treated lesions at D65. No adverse reactions were reported.

CONCLUSION

Given the positive results of this first clinical study, it would be interesting to extend the study to confirm the validity of this type of therapy in sterile pyogranulomatous pododermatitis in the dog.

Simultaneous bilateral laser therapy accelerates recovery after noise-induced hearing loss in a rat model

Noise-induced hearing loss is a common type of hearing loss. The effects of laser therapy have been investigated from various perspectives, including in wound healing, inflammation reduction, and nerve regeneration, as well as in hearing research. A promising feature of the laser is its capability to penetrate soft tissue; depending on the wavelength, laser energy can penetrate into the deepest part of the body without damaging non-target soft tissues. Based on this idea, we developed bilateral transtympanic laser therapy, which uses simultaneous laser irradiation in both ears, and evaluated the effects of bilateral laser therapy on cochlear damage caused by noise overexposure. Thus, the purpose of this research was to assess the benefits of simultaneous bilateral laser therapy compared with unilateral laser therapy and a control. Eighteen Sprague-Dawley rats were exposed to narrow-band noise at 115 dB SPL for 6 h. Multiple auditory brainstem responses were measured after each laser irradiation, and cochlear hair cells were counted after the 15th such irradiation. The penetration depth of the 808 nm laser was also measured after sacrifice. Approximately 5% of the laser energy reached the contralateral cochlea. Both bilateral and unilateral laser therapy decreased the hearing threshold after noise overstimulation in the rat model. The bilateral laser therapy group showed faster functional recovery at all tested frequencies compared with the unilateral laser therapy group. However, there was no difference in the endpoint ABR results or final hair cell survival, which was analyzed histologically.

Effectiveness of Single Session of Low-Level Laser Therapy with a 940 nm Wavelength Diode Laser on Pain, Swelling, and Trismus After Impacted Third Molar Surgery

INTRODUCTION

In low-level laser therapy (LLLT), applications are generally performed in repetitive sessions using wavelengths of around 800 nm, at which the depth of penetration of laser is greater. The present study aimed to investigate the effects of LLLT with a 940 nm diode laser, which was performed extraorally on all the primarily and secondarily affected areas immediately after surgery in a single session, on pain, swelling, and trismus that occurred after impacted tooth extraction.

MATERIALS AND METHODS

Thirty-five outpatients with similarly impacted lower third molars on both sides were selected. The teeth of patients were removed in two separate operations. Postoperatively, the patients received laser therapy with energy of 4 J/cm(2) on one side and no laser energy was applied to the other side (placebo side). Swelling, trismus, and subjective assessment of pain on a visual analog scale were evaluated and compared between the laser-treated and placebo sides.

RESULTS

There was no statistically significant difference in pain, swelling, or trismus between the sides (Mann-Whitney U test p > 0.05). However, according to the clinical outcomes, swelling and trismus were less in the laser-treated side than in the placebo side.

CONCLUSIONS

A single-session LLLT that would be applied with a diode laser immediately after impacted tooth extraction might help patients to be less affected by postoperative trismus and swelling.

Effects of low-level laser therapy on the serum TGF-β1 concentrations in individuals with autoimmune thyroiditis

OBJECTIVE

The objective of this study was to evaluate the serum concentration of transforming growth factor-β1 (TGF-β1) after low-level laser therapy (LLLT) in patients with hypothyroidism resulting from chronic autoimmune thyroiditis (CAT).

BACKGROUND DATA

Certain data indicate that LLLT is effective in patients with hypothyroidism caused by CAT; however, the mechanisms of action of LLLT in thyroid tissue are unknown. Cytokines could play a role in the response to LLLT.

METHODS

A randomized, placebo-controlled trial included 43 patients with a history of levothyroxine therapy for CAT-induced hypothyroidism. The patients were randomly assigned to receive either 10 sessions of LLLT (830 nm, 50 mW output power, and 707 J/cm(2) fluence; L group, n=23) or 10 sessions of a placebo treatment (P group, n=20) twice a week. Levothyroxine was maintained at the same dose during the entire study period. TGF-β1 was measured both pre-intervention and 30 days post-intervention in both groups. The differences were calculated between the TGF-β1 values observed 30 days post-intervention and the pre-intervention TGF-β1 values for each group (intragroup).

RESULTS

Comparing the differences in TGF-β1 levels between the L group (874.9±541.7 pg/mL) and the P group (-128.4±832.8 pg/mL) revealed that there was a statistically significant increase in TGF-β1 levels 30 days post-intervention in group L compared with the placebo group (p=0.0379).

CONCLUSIONS

This finding suggested that the significant increase in serum TGF-β1 levels in patients with CAT-induced hypothyroidism was associated with the thyroid LLLT procedure. Future studies of the effect of LLLT on TGF-β1 gene expression in thyroid tissue are necessary to confirm these findings.

Safety and patient subjective efficacy of using galvanopuncture for the treatment of striae distensae

BACKGROUND

Striae distensae are linear atrophic dermal scars with associated epidermal atrophy. This recurrent skin disorder causes a significant cosmetic and psychologic concern and remains a therapeutic challenge, especially when they are mature and hypopigmented (striae alba).

AIMS

In this prospective single-center study, we evaluated the efficacy, safety, and patient's satisfaction of galvanopuncture for the treatment of striae alba.

PATIENTS/METHODS

Thirty-two female subjects with striae alba present on the buttocks were treated with galvanopuncture once a week over a period of 10 weeks. Photographs and a percentage category scale were used to assess striae improvement and patient's satisfaction. Biochemical analyses were performed to assess possible systemic inflammatory effects or oxidative stress induction by the treatment.

RESULTS

All patients achieved a substantial increase in clinical improvement in their striae within 10 treatment sessions. Galvanopuncture did not induce any inflammatory effect; however, it reduced oxidative injury.

CONCLUSION

The use of galvanopuncture for the treatment of striae alba demonstrated a significant improvement in the lesions with visible results. This study supports the high degree of patient's satisfaction and demonstrate the safe and effective use of galvanopuncture in the treatment of striae alba on several skin types.