Infrared (810-nm) low-level laser therapy on rat experimental knee inflammation

Lasers efficacy in pain management after primary and secondary endodontic treatment: a systematic review and meta-analysis of randomized clinical trials

Postoperative pain is a common concern following root canal treatments (RCT), impacting both patients and oral health practitioners. This systematic review and meta-analysis aimed to evaluate the effectiveness of laser treatment modalities in reducing postoperative pain compared to conventional methods after primary and secondary RCT in permanent mature teeth. A search of three electronic databases (PubMed, ScienceDirect, and The Cochrane Library) was conducted, using a broad range of keywords and terms. Gray literature and manual searches were conducted to complement the search. The inclusion criteria included randomized clinical trials based on the objective of the secondary study. A minimum sample size of 10 participants per group and a clearly defined criterion for postoperative pain assessment were required. The characteristics of the included studies were presented as tables. The Cochrane collaboration tool RoB 2.0 was used to assess the risk of bias within each study. Two reviewers extracted the data and assessed the studies independently, and discrepancies were resolved through consultation with a third reviewer. A random-effects model was employed for meta-analysis to estimate the overall effect measure. Heterogeneity was evaluated using Cochran's Q test and the I2 index. Publication bias was explored via Funnel plots and Egger's test. Subgroup analyses and meta-regression were conducted to assess variations among laser methods and examine the influence of independent factors. The significance threshold for all analyses was set at 5% (α = 0.05). Intraoral laser therapy demonstrated no significant advantage over conventional treatments but consistently outperformed placebo, particularly from 4 to 72 h post-treatment. Low-level laser therapy provided slight pain reduction in the first 8 h, though its effectiveness diminished in retreatment scenarios. Photodynamic therapy and laser disinfection showed marginal benefits, especially shortly after treatment, with reduced efficacy in longer-term or retreatment contexts. Further research is needed to explore different applications of laser modalities and assess distinct prognostic factors in more detail.

A systematic review and network meta-analysis on the optimal wavelength of low-level light therapy (LLLT) in treating knee osteoarthritis symptoms

OBJECTIVES

To compare the efficacy of the various wavelengths of low-level light therapy (LLLT) in alleviating knee pain, dysfunction, and stiffness in patients with knee osteoarthritis (KOA), and to compare the effectiveness of LLLT versus sham treatment in reducing knee pain, dysfunction, and stiffness.

METHODS

PubMed, Web of Science, EMBASE, and Cochrane Library were searched from inception to 12 December 2023. Randomized controlled trials that assessed the effects of different wavelengths of LLLT on alleviating pain of patients with KOA were included. A conventional meta-analysis and network meta-analysis were preformed, and standardized mean differences (SMD) with 95% confidence interval (CI) were calculated.

RESULTS

Thirteen studies involving 673 participants with KOA met inclusion criteria. Overall, LLLT was superior to sham LLLT for relieving pain (SMD = 0.96, 95% CI 0.31-1.61) but not for improving function (SMD = 0.21, 95% CI - 0.11 to 0.53) or stiffness (SMD = 0.07, 95% CI - 0.25 to 0.39). Surface under the cumulative ranking curve (SUCRA) value ranking showed the most effective wavelength of LLLT in reducing KOA pain was 904-905 nm (SUCRA, 86.90%), followed by multi-wavelengths (MWL) (SUCRA, 56.43%) and 785-850 nm (SUCRA, 54.97%). Compared to sham LLLT, L2 (SMD = 1.42, 95% CI = 0.31-2.53) and L1 (SMD = 0.82; 95% CI = 0.11-1.50) showed a significant reduction in KOA pain. However, MWL (SMD = 0.83; 95% CI = - 0.06 to 1.72) showed similar KOA pain reduction compared to sham LLLT. The certainty of evidence showed that the quality of evidence regarding the effectiveness of overall LLLT versus sham, and 904-905 nm versus sham were low, while the quality of evidence for MWL versus sham, and 785-850 nm versus sham was very low.

CONCLUSION

While the 904-905 nm wavelength showed potential benefits in reducing KOA pain, the overall quality of the evidence was low. LLLT with 904-905 nm or 785-850 nm wavelengths yielded significantly better reduction in KOA pain compared to sham LLLT, but further high-quality research is warranted to validate these findings.

Long wavelength light exposure reduces systemic inflammation coagulopathy and acute organ injury following multiple injuries in mice

BACKGROUND

Evidence suggests that variation in light exposure strongly influences the dynamic of inflammation, coagulation, and the immune system. Multiple injuries induce systemic inflammation that can lead to end-organ injury. Here, we hypothesize that alterations in light exposure influence posttrauma inflammation, coagulopathy, and end-organ injury.

METHODS

C57BL/6 mice underwent a validated multiple-injury and hemorrhage model performed following 72 hours of exposure to red (617 nm, 1,700 lux), blue (321 nm, 1,700 lux), and fluorescent white light (300 lux) (n = 6-8/group). The animals were sacrificed at 6 hours posttrauma. Plasma samples were evaluated and compared for proinflammatory cytokine expression levels, coagulation parameters, markers of liver and renal injury, and histological changes (Carstairs staining). One-way analysis of variance statistical tests were applied to compare study groups.

RESULTS

Preexposure to long-wavelength red light significantly reduced the inflammatory response at 6 hours after multiple injuries compared with blue and ambient light, as evidenced by decreased levels of interleukin 6, monocyte chemoattractant protein-1 (both p < 0.001), liver injury markers (alanine transaminase, p < 0.05), and kidney injury markers (cystatin C, p < 0.01). In addition, Carstairs staining of organ tissues revealed milder histological changes in the red light-exposed group, indicating reduced end-organ damage. Furthermore, prothrombin time was significantly lower ( p < 0.001), and fibrinogen levels were better maintained ( p < 0.01) in the red light-exposed mice compared with those exposed to blue and ambient light.

CONCLUSION

Prophylactic light exposure can be optimized to reduce systemic inflammation and coagulopathy and minimize acute organ injury following multiple injuries. Understanding the mechanisms by which light exposure attenuates inflammation may provide a novel strategy to reducing trauma-related morbidity.

Photodynamic therapy mediated by methylene blue-loaded PEG accelerates skin mouse wound healing: an immune response

PURPOSE

Conventional approaches for enhancing wound healing may not always yield satisfactory results. Instead, we test the effectiveness of a newly developed photodynamic therapy (PDT) that uses methylene blue (MB) loaded with polyethylene glycol (PEG) (MB-PEG) hydrogel to accelerate wound healing process in mice.

METHODS

A dorsal skin incision with 6 mm punch which topically subjected to MB-PEG hydrogel and a low-level laser light of red light to assess the regeneration process of wounded skin. A total of 63 adult male CD1 mice divided into normal group (no treatment) and other wound groups received different treatments of laser (650 ± 5 nm and power intensity of 180 mW/cm2), MB-PEG, or PDT (MB-PEG followed by laser). The wound healing parameters were investigated by histological examination of the skin and measuring of proinflammatory cytokines at the early stage (48 h) and a late one on day 21.

RESULTS

at 48 h, the score of tissue granulation, inflammation, and angiogenesis process were markedly improved in wounded groups that received MB + PEG combined with laser compared to the group treated with laser alone. On day 21, a significant improvement of the inflammation was detected in the group treated with MB + PEG plus laser compared to the other groups. At 48 h, the upregulated serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the wound group were significantly (P < 0.001) reduced in the group treated with MB + PEG combined with laser.

CONCLUSION

MB-PEG based hydrogel improves and accelerates wound closure in the context of laser compared to either single treatment.

A systematic review and meta-analysis on the effects of phototherapy on postoperative pain in conventional endodontic reintervention

OBJECTIVES

This systematic review and meta-analysis (SRM) aimed to evaluate the efficacy of laser phototherapy (LPT) on the reduction in postoperative pain (PP) of endodontic origin after conventional/non-surgical reintervention of root canals.

METHODS

This SRM was registered with PROSPERO (CRD42021243500) and followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Meta-analysis was conducted using R software with the "META" package, the mean difference (MD) measure of effect was calculated, and the fixed effect model was applied with a 95% confidence interval (CI). The Cochrane collaboration scale was used to assess the risk of bias and the GRADE tool to assess the quality of evidence.

RESULTS

Initially, 1028 articles were found, and five articles were included. Most studies were classified as "low" risk of bias. Of the five clinical studies, four showed a significant decrease in PP after endodontic reintervention in the LPT groups compared to the control group, especially in the first four days after the intervention. In symptomatic teeth with multiple roots, LPT led to less PP at 24 h (MD -0.52 [-1.03; -0.02] p = .04). However, no significant difference between the groups was found at 48 and 72 h (p > .05). The certainty of the evidence was classified as low.

CONCLUSION

Despite the limitations of this SRM, LPT was shown to be a promising alternative for reducing and controlling PP in conventional endodontic reintervention.

CLINICAL SIGNIFICANCE

The use of LPT in endodontic reintervention may be a safe and promising alternative to clinically efficacious agent for use in the management of PP in this procedure.

The Effects and Mechanisms of PBM Therapy in Accelerating Orthodontic Tooth Movement

Malocclusion is one of the three major diseases, the incidence of which could reach 56% of the imperiled oral and systemic health in the world today. Orthodontics is still the primary method to solve the problem. However, it is clear that many orthodontic complications are associated with courses of long-term therapy. Photobiomodulation (PBM) therapy could be used as a popular way to shorten the course of orthodontic treatment by nearly 26% to 40%. In this review, the efficacy in cells and animals, mechanisms, relevant cytokines and signaling, clinical trials and applications, and the future developments of PBM therapy in orthodontics were evaluated to demonstrate its validity. Simultaneously, based on orthodontic mechanisms and present findings, the mechanisms of acceleration of orthodontic tooth movement (OTM) caused by PBM therapy were explored in relation to four aspects, including blood vessels, inflammatory response, collagen and fibers, and mineralized tissues. Also, the cooperative effects and clinical translation of PBM therapy in orthodontics have been explored in a growing numbers of studies. Up to now, PBM therapy has been gaining popularity for its non-invasive nature, easy operation, and painless procedures. However, the validity and exact mechanism of PBM therapy as an adjuvant treatment in orthodontics have not been fully elucidated. Therefore, this review summarizes the efficacy of PBM therapy on the acceleration of OTM comprehensively from various aspects and was designed to provide an evidence-based platform for the research and development of light-related orthodontic tooth movement acceleration devices.

Twenty cases of perennial and seasonal allergic rhinitis treated with LumiMed® Nasal Device

BACKGROUND

Allergic rhinitis is the most common allergic disease, with a prevalence up to 40% in the general population. Allergic rhinitis requires daily treatment to block inflammatory mediators and suppress the inflammatory response. However, these medications may have harmful side effects. Photobiomodulation as a treatment modality to reduce inflammation has been beneficial in many chronic disorders, yet therapy has not been US Food and Drug Administration approved for the treatment of allergic rhinitis. The LumiMed Nasal Device was designed to address the limitations associated with the treatment of allergic rhinitis with photobiomodulation. This in-office study hopes to show efficacy, usability, and comfortability of the LumiMed Nasal Device.

CASE PRESENTATION

Twenty patients with allergic rhinitis were treated during high allergy season with LumiMed Nasal Device. The average age of patients was 35 years (10-75); 11 were female and 9 were male. The population's ethnicities were white (n = 11), Black (n = 6), Oriental (n = 2), and Iranian (n = 1). Patients were treated with twice-daily dosing, 10 seconds in each nostril, for 10 consecutive days. After 10 days, patients were evaluated for symptom relief, device comfort and device ease of use. The Total Nasal Symptom Score was used to assess severity of main symptoms of allergic rhinitis. The sum of Total Nasal Symptom Scores for each symptom category was calculated (total possible scores per patient were 0-9). Rhinorrhea/nasal secretions, nasal congestion, and nasal itching/sneezing were evaluated on a scale of 0-3 (0 no symptoms, 1 mild symptoms, 2 moderate symptoms, 3 severe symptoms). Device comfort was evaluated on a scale of 0-3 (0 no discomfort, 1 mild discomfort, 2 moderate discomfort, 3 severe discomfort). Device ease of use was evaluated on a scale of 0-3 (0 very easy, 1 somewhat difficult, 2 difficult, 3 very difficult).

CONCLUSIONS

The results from these case studies indicated that of the 20 patients in this case study, 100% of patients experienced improvement in overall Total Nasal Symptom Score after using LumiMed Nasal Device. Of those patients, 40% brought their Total Nasal Symptom Score down to 0. Furthermore, 95% felt the LumiMed Nasal Device was comfortable to use, while 85% of patients felt the LumiMed Nasal Device was easy to use.

Efficiency of diode laser in control of post-endodontic pain: a randomized controlled trial

OBJECTIVES

As post-endodontic pain control is one of the main targeted addressed in endodontics, our aim was delignated to compare two different methods for low-level laser application utilizing diode laser: low-level laser therapy (LLLT) and laser-activated irrigation (LAI) in the control of post-endodontic pain.

MATERIALS AND SUBJECTS

A total of 180 patients received single-visit root canal treatment; they were randomly allocated into 3 equal groups. Group I received LAI, group II received LLLT, and group III served as control with normal root canal treatment and mock laser intervention (ML group). Postoperative pain was recorded using visual analogue scale (VAS) after 24, 48, and 72 h. Data were tabulated and statistically analyzed.

RESULTS

At 24 h, there was a statistically significant difference between median pain scores in the three groups (P value < 0.001) with ML group scored highest score followed by LAI and then LLLT group. At 48 h, there was a statistically significant difference between the three groups (P value < 0.001), with ML group scoring highest median pain scores while LLLT and LAI showed statistical insignificant scores. At 72 h, there was no statistically significant difference between the 3 groups (P value = 0.179).

CONCLUSION

LLLT is superior to LAI and ML group in the control of immediate postoperative pain after 24 h while after 48 h both LAI and LLLT were equally effective, but they still showed significant differences when compared to ML group.

CLINICAL RELEVANCE

Diode laser can be used by clinicians as it decreases the post-endodontic pain in patients with symptomatic apical periodontitis undergoing endodontic treatment.

Effects of low-level laser therapy and therapeutic ultrasound on Freund's complete adjuvant-induced knee arthritis model in rats

OBJECTIVES

The aim of this study was to evaluate and monitor the effect of low-level laser therapy (LLLT) and therapeutic ultrasound (TU) alone, or combined with intra-articular prednisolone (P) in Freund's complete adjuvant (FCA)-induced knee arthritis model in rats.

MATERIALS AND METHODS

A total of 56 adult male Wistar rats were divided into seven groups: control (C), disease control (RA), P, TU, LLLT (L), P + TU (P+TU), P + LLLT (P+L) groups. The skin temperature, radiography, joint volume, serum rheumatoid factor (RF), interleukin (IL)-1β, serum tumor necrosis factor-alpha (TNF-α), and histopathological evaluation of joint were performed.

RESULTS

Thermal imaging and radiographic examination provided results consistent with the severity of the disease. The mean joint temperature (°C) was the highest in the RA (36.2±1.6) group on Day 28. The P+TU and P+L groups significantly decreased radiological scores at the end of the study. The rat serum TNF-α, IL-1β, and RF levels in all groups were significantly higher compared to the C group (p<0.05). Compared to the RA group, serum TNF-α, IL-1β, and RF levels were significantly lower in the treatment groups (p<0.05). The P+TU and P+L group was showed minimal chondrocyte degeneration and cartilage erosion and mild cartilage fibrillation and mononuclear cell infiltration of synovial membrane compared to the P, TU, and L group.

CONCLUSION

The LLLT and TU effectively reduced inflammation. In addition, a more effective result was obtained from the use of LLLT and TU combined with intra-articular P. This result may be due to insufficient dose of LLLT and TU, thus further studies should be focus on at higher dose ranges on FCA arthritis model in rats.

Low-Level Laser and Light Therapy After Total Knee Arthroplasty Improves Postoperative Pain and Functional Outcomes: A Three-Arm Randomized Clinical Trial

Background

We examined the effect of low-level laser therapy (LLLT) and Bioptron light therapy on pain and function following primary total knee arthroplasty.

Methods

A single-center, single-surgeon, prospective randomized clinical trial was performed with 3 groups of 15 patients: LLLT (804 nm), light (Bioptron; Bioptron AG, Wollerau, Switzerland), and controls. Range of motion (ROM), visual analog scale pain, opiate consumption (oxycodone in milligrams), knee swelling, and the Knee Society Score (KSS) were assessed before the surgery and on postoperative day 2, postoperative day 3, month 3, and month 12 after the operation.

Results

The preoperative scores were similar between groups. A higher ROM was observed with the LLLT group at all follow-ups except at the 12-month follow-up (3-month ROM: 116.8° vs 104.0° vs 92.3°; P < .001). The knee swelling at 3 months was similar between the LLLT and light groups (2.1 cm), which was lower than that in controls (2.1 cm, P < .001). Furthermore, visual analog scale pain decreased more in the LLLT group than in other groups (8.5 vs 7.2 vs 6.0 points) at 3 months (P = .04) but was similar at 12 months (P > .05). Also, the LLLT group consumed fewer opiate painkillers during the first month (48.3 vs 60.3 mg of oxycodone, P = .02). In the LLLT group, the KSS at 3 and 12 months and the KSS function score at 3 months exceeded minimally clinically important differences (P < .05).

Conclusions

In the early stages of recovery after total knee arthroplasty, LLLT and Bioptron light therapy could be helpful to control immediate and acute knee pain and swelling, reduce the need for opioids, improve ROM and functional scores, and improve recovery.

Level of Evidence

Therapeutic level I.

Short-Term Efficacy of High-Intensity Laser Therapy in Alleviating Pain in Patients with Knee Osteoarthritis: A Single-Blind Randomised Controlled Trial

Objectives

The aim of the study is to evaluate the efficacy of high-intensity laser therapy (HILT) on pain reduction in patients with knee osteoarthritis (OA).

Methods

Forty-two patients diagnosed with primary knee OA, with a Kellgren–Lawrence classification of 2–4, were recruited into the study. The patients were randomly allocated to two groups: HILT and control. The intervention group received HILT (energy density of 22.39 J/cm2, 562.5 joule/session), while the control group received a sham laser, which was done 2–3 sessions per week for a total of 10 sessions. Both the groups also received the same conservative treatment. The main outcome measures were the visual analogue scale (VAS) and the modified Thai version of the Western Ontario and McMaster Universities Osteoarthritis Index (T-WOMAC) which were evaluated at baseline and immediately after treatment completion.

Results

At the end of the study, the overall analysis showed a significant decrease in VAS and T-WOMAC scores in both the groups; a greater decrease in scores was found in the HILT group than in the control group (p < 0.001). The between-group comparison also showed a significant difference in VAS, but not in the T-WOMAC score, favouring HILT (p < 0.05).

Conclusion

The HILT plus conservative treatment can help alleviate pain in patients with knee OA. The findings of the present study could be used in clinical practice to add HILT as another noninvasive treatment option for knee OA. This could be advantageous, particularly for individuals who are at high risk of surgery due to multiple comorbidities or older people. Trial Registration. This clinical trial registration was performed at Clinical.gov (NCT04889885).

Effects of Combined Visible and Infrared Light Rhinophototherapy in Patients With Allergic Rhinitis

BACKGROUND

Intranasal phototherapy offers an alternative treatment method for patients with allergic rhinitis who cannot benefit from intranasal corticosteroids and oral antihistamines. Different wavelengths have been tried with promising results.

OBJECTIVE

In this present study, we aimed to investigate the effects of visible light-infrared light phototherapy on clinical improvements together with its cytologic effects in patients with allergic rhinitis.

METHODS

Patients with confirmed allergic rhinitis were given a 4-week course of intranasal phototherapy treatment. Weekly symptom questionnaires were applied to monitor clinical effects. Nasal lavage specimens were obtained before the start and at the completion of the 4-week therapy. Fluorescence-activated cell sorting analyses of CD16⁺, CD24⁺, and CD 45⁺ cells were performed. Statistical analyses are performed of weekly changes in symptoms and cell counts.

RESULTS

CD45⁺CD16^highCD24⁺ neutrophil count in nasal lavages decreased significantly whereas CD45⁺CD16^dim/-CD24⁺ eosinophil counts significantly increased and CD45⁺ granulocyte counts remained unchanged. Symptom scores including nasal itching, nasal discharge, nasal obstruction, sneezing, eye itching, throat itching, and ear itching all statistically decreased compared to baseline at the end of 4 weeks.

CONCLUSION

Four-week course of intranasal phototherapy with visible and infrared light leads to clinical improvement in allergic rhinitis patients.

Photobiomodulation effects in metalloproteinases expression in zymosan-induced arthritis

Matrix metalloproteinases (MMPs) play a crucial role in the degenerative course of rheumatic disorders. They are responsible for cartilage and other joint-associated tissues breakdown. Amid arthritis treatments, photobiostimulation (PBM), a non-thermal and non-invasive low-power laser application, appears to be an outstanding therapy alternative once it has succeeded in MMPs modulation. Thus, this study aimed to evaluate the PBM effects of low infrared laser (830 nm), testing two different energy densities (3 and 30 Jcm^-2) in MMP-2, MMP-9, MMP-13, and MMP-14 as well as the inhibitor TIMP-2 expressions using zymosan-induced arthritis model. C57BL/6 mice were distributed into four groups (n = 8): zymosan-induced arthritis without treatment; zymosan-induced arthritis and dexamethasone-treated; zymosan-induced arthritis and PBM at energy density of 3 Jcm^-2 treated; and zymosan-induced arthritis and PBM at energy density of 30 Jcm^-2 treated. MMPs and TIMP-2 mRNA relative levels by qRT-PCR and proteins expression by immunohistochemical and Western blotting techniques were performed after PBM treatment in the inflamed joint. Our results demonstrated PBM could modulate both mRNA relative levels and proteins expression of the MMP-2, -9, -13, -14, and TIMP-2 in joint tissues, decreasing MMP-9 protein expression and increasing TIMP-2 protein expression. PBM promotes a better arthritis prognostic, modulating metalloproteinase and its inhibitor, especially MMP-9 and TIMP-2 protein expression that is important inflammatory markers. These findings may also corroborate that PBM may regulate MMPs expression using different pathways.

Short- and Long-Term Effectiveness of Low-Level Laser Therapy Combined with Strength Training in Knee Osteoarthritis: A Randomized Placebo-Controlled Trial

Background: Both physical activity and low-level laser therapy (LLLT) can reduce knee osteoarthritis (KOA) inflammation. We conducted a randomized clinical trial to investigate the short- and long-term effectiveness of LLLT combined with strength training in persons with KOA. Methods: Fifty participants were randomly divided in two groups, one with LLLT plus strength training (n = 26) and one with placebo LLLT plus strength training (n = 24). LLLT and strength training were performed triweekly for 3 and 8 weeks, respectively. In the laser group, 3 joules 904 nm wavelength laser was applied to fifteen points (45 joules) per knee per session. Patient-reported outcomes, physical tests, and ultrasonography assessments were performed at baseline and 3, 8, 26, and 52 weeks after initial LLLT or placebo therapy. The primary outcomes were pain on movement, at rest, at night (Visual Analogue Scale), and globally (Knee injury and Osteoarthritis Outcome Score (KOOS) subscale). Parametric data were assessed with analysis of variance using Šidák’s correction. Results: There were no significant between-group differences in the primary outcomes. However, in the laser group there was a significantly reduced number of participants using analgesic and non-steroidal anti-inflammatory drugs and increased performance in the sit-to-stand test versus placebo-control at week 52. The joint line pain pressure threshold (PPT) improved more in the placebo group than in the laser group, but only significantly at week 8. No other significant treatment effects were present. However, pain on movement and joint line PPT were worse in the placebo group at baseline, and therefore, it had more room for improvement. The short-term percentage of improvement in the placebo group was much higher than in similar trials. Conclusions: Pain was reduced substantially in both groups. LLLT seemed to provide a positive add-on effect in the follow-up period in terms of reduced pain medication usage and increased performance in the sit-to-stand test.

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.

Laser-photobiomodulation on titanium implant bone healing in rat model: comparison between 660- and 808-nm wavelength

Laser-photobiomodulation (L-PBM) has been widely studied and its biomodulatory effects have been established on irradiated cells, increasing viability and proliferation and on damaged tissues. In addition, L-PBM may reduce and modulate the inflammatory process. The effect of 660-nm and 808-nm laser-photobiomodulation on bone repair around titanium dental implants placed in rat's femur was evaluated by histomorphometry. Twenty-seven Wistar rats were divided into 3 groups of nine animals: group C - non-irradiated control; group R - λ=660nm irradiated; and group IR - λ=808nm irradiated. Each group was further divided in 3 subgroups of three animals each, according to histomorphometry analysis in 3 days, 7 days, and 14 days after irradiation. Histological H.E.-stained slides were photographed, and bone matrix measured in new-formed bone area. Bone matrix histomorphometry analysis indicates that at 7 days in the irradiated groups (R and IR), a bigger area matrix was observed in relation to control group (C) (p=0.04 and p=0.048 respectively). On the other hand, at 14 days, control group (C) presented a bigger area than infrared irradiated (IR) (p=0.001) and red irradiated group (R) also showed a bigger area than infrared irradiated group (IR) (p=0.019). Histological analysis indicates that irradiated groups (R and IR) exhibited a faster bone tissue matrix production than control group.

The effect of photodynamic therapy on postoperative pain in teeth with primary endodontic infection

INTRODUCTION

The objective of this study was to investigate the action of photodynamic therapy on pain control after endodontic treatment in asymptomatic teeth with a primary infection, within a single visit.

METHODS

Sixty (60) single-rooted teeth with pulp necrosis and periapical lesions were selected and randomly divided into two (2) groups (n=30), according to the protocol; a control group (CG) and a group using photodynamic therapy (aPDT). The canals were instrumented with Reciproc files # 25 up to 40 along the entire length of the canal, using 2% chlorhexidine gel as the auxiliary chemical substance, followed by irrigation with sterile saline. The canals were filled with Endomethasone N cement, 0.005% methylene blue, using AsGaAl diode laser, 660 nm wavelength, 100 mW of power and 9 J of energy, using optical fibers with 365 µm in diameter.

RESULTS

Pain intensity was assessed at 8, 12, 24, 48, 72 hours and 1 week after endodontic treatment using a visual analogue scale. The level of pain was classified as none (0), mild (1-3), moderate (4-7) or severe (8-10). The data were at a significance level of 5%. There was a statistically significant difference (p<0.05) in the periods of 8, 12, 24, 48 and 72 hours between the control group and the aPDT group. After 1 week, there was no statistically significant difference.

CONCLUSIONS

It is concluded that photodynamic therapy had a significant effect on decreasing post-endodontic treatment pain in teeth with necrotic pulp and asymptomatic periapical lesions.

Fluorescent Light Energy and Chronic Lesions: A Winning Association

Background:

Chronic ulcers represent a challenge for healthcare professionals and a large expense for national health care systems for their difficulty in achieving complete healing and for their high incidence of recurrence. With the progressive aging of the general population, the incidence of these injuries will only increase, further affecting the public health budget, hence the need to find new strategies for their management. The purpose of this study was to share the experience of the Complex Operational Unit of Plastic Surgery of the University Hospital of Padua with fluorescent light energy therapy, outlining its role in the treatment of chronic ulcers in the daily use outside the previous EUREKA study.

Methods:

In this case series study, we enrolled 15 patients with chronic ulcers of any etiology between January 2018 and July 2019 and we treated them using fluorescence light energy. We evaluated efficacy and safety endpoints reporting data in excel files completed by medical staff during the study.

Results:

The study confirms the effectiveness of fluorescent light energy inducing chronic ulcer healing, regardless of etiology, or at least preparing the lesions for a skin graft closure surgery. The system showed a low rate of complications established by patient adherence to treatment. Patients also reported a reduction in pain both at home and during outpatient dressings.

Conclusion:

Based on our experience, fluorescent light energy shows an excellent safety and efficacy profile in chronic ulcers no more responsive to traditional dressings and/or surgery.

Photobiomodulation as an Adjunctive Treatment to Physiotherapy for Reduction of Anterior Knee Pain in Combat Soldiers: A Prospective, Double-Blind, Randomized, Pragmatic, Sham-Controlled Trial

BACKGROUND AND OBJECTIVES

Anterior knee pain (AKP) is the most common knee pathology in athletes and occurs in 15% of army recruits of elite units during basic training. Of these, 50% are symptomatic 6 years later. Photobiomodulation (PBM) is a nonthermal red-to-near-infrared irradiation used for pain reduction of a variety of etiologies. This study was designed to determine whether addition of PBM to physiotherapy (PT) for AKP in combat soldiers is superior to PT alone.

STUDY DESIGN/MATERIALS AND METHODS

In this prospective, double-blind, sham-controlled, randomized clinical trial (NCT02845869), 26 combat soldiers/policemen (male:female, 15:11; body mass index [BMI] = 24.2 ± 3.9, n = 46 knees), with AKP due to overuse/load, received 4 weeks of PT + sham (PT + Sham) or active PBM (wavelength = 660 and 850 nm, pulsing = 2.5 Hz, LED power = 50 mW/cm² [local tissue/regional lymph nodes]; 810 nm continuous beam, laser cluster 6 W/cm² [analgesia] and laser pointer 4.75 W/cm² [trigger points]) (PT + PBM). The main outcome measures were subjective pain by visual analog scale (VAS) (0 [none]-100 [intolerable]) and functional disability by Kujala score (0 [worst]-100 [best]). Evaluations were carried out at baseline, end of treatments, and 3-month follow-up.

RESULTS

All participants completed the treatment protocol without any reported adverse device effects. Post-treatment pain was significantly reduced in the PT+PBM group, compared with baseline and sham (Δpain, VAS, mean ± SD: PT + PBM = -19 ± 23, P = 0.002; PT + Sham = -6 ± 21, P = 0.16; between groups, P = 0.032). At 3-month follow-up, pain reduction was similar between groups; however, the Kujala score was significantly improved only in the PBM-treated group (ΔKujala: PT + PBM = 11 ± 10, P = 0.003; PT + Sham = 5 ± 7, P = 0.059).

CONCLUSIONS

Addition of PBM to PT for AKP resulted in earlier reduction in pain and improved functionality, compared with PT alone. This noninvasive, nonpharmacologic, adjunctive therapeutic modality can be easily incorporated into team healthcare frameworks or end units and may lead to earlier return to competition or combat-level service. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Treadmill Exercise after Controlled Abnormal Joint Movement Inhibits Cartilage Degeneration and Synovitis

Cartilage degeneration is the main pathological component of knee osteoarthritis (OA), but no effective treatment for its control exists. Although exercise can inhibit OA, the abnormal joint movement with knee OA must be managed to perform exercise. Our aims were to determine how controlling abnormal joint movement and treadmill exercise can suppress cartilage degeneration, to analyze the tissues surrounding articular cartilage, and to clarify the effect of treatment. Twelve-week-old ICR mice (n = 24) underwent anterior cruciate ligament transection (ACL-T) surgery on their right knees and were divided into three groups as follows: ACL-T, animals in the walking group subjected to ACL-T; controlled abnormal joint movement (CAJM), and CAJM with exercise (CAJM + Ex) (n = 8/group). Walking-group animals were subjected to treadmill exercise 6 weeks after surgery, including walking for 18 m/min, 30 min/day, 3 days/week for 8 weeks. Safranin-O staining, hematoxylin-eosin staining, and immunohistochemical staining were performed. The OARSI (Osteoarthritis research Society international) score was lower in the CAJM group than in the ACL-T group and was even lower in the CAJM + Ex group. The CAJM group had a lower meniscal injury score than the ACL-T group, and the CAJM + Ex group demonstrated a less severe synovitis than the ACL-T and CAJM groups. The observed difference in the perichondrium tissue damage score depending on the intervention method suggests different therapeutic effects, that normalizing joint motion can solve local problems in the knee joint, and that the anti-inflammatory effect of treadmill exercise can suppress cartilage degeneration.

Photobiomodulation exerts anti-inflammatory effects on the vascular and cellular phases of experimental inflammatory models

Photobiomodulation therapy (PBMT) is a non-thermal therapeutic procedure widely used in clinical practice. It is considered an effective modality of treatment for the control of various inflammatory conditions with fewer adverse effects as compared to conventional therapy. However, despite the clinical effects, the mechanisms of action and dosimetric parameters of PBMT are not fully understood. This study was performed to describe the effects of two different doses of PBMT on experimental models of inflammation. Male Swiss mice were administered with 0.9% of saline or phlogistic agents (carrageenan, dextran, serotonin, histamine, or bradykinin) by intra-plantar injection and were treated with PBMT at a dose of 1 or 5 J/cm²; right after, the variation of the paw volume was made, and histopathological analysis and myeloperoxidase assay of the carrageenan-induced edematous paw tissues were performed. The action of PBMT on carrageenan-induced vascular permeability was further evaluated. Our results showed that PBMT (1 J/cm²) led to an improvement in paw edema induced by the phlogistic agents and further reduced the histological scores. Inhibition of neutrophil migration was observed following the administration of 1 and 5 J/cm² of PBMT. However, only 1 J/cm² of PBMT showed beneficial effects on carrageenan-induced edema. Laser at a dose of 1 J/cm² showed cellular and vascular effects since it was able to reverse all the inflammatory parameters, and laser at a dose of 5 J/cm² probably has only cellular effects in the presence of acute inflammation.

Effectiveness of Low-Level Laser Therapy Associated with Strength Training in Knee Osteoarthritis: Protocol for a Randomized Placebo-Controlled Trial

Physical activity and low-level laser therapy (LLLT) can reduce knee osteoarthritis (KOA) inflammation. We are conducting a randomized placebo-controlled trial to investigate the long-term effectiveness of LLLT combined with strength training (ST) in persons with KOA, since it, to our knowledge, has not been investigated before. Fifty participants were enrolled. LLLT and ST was performed 3 times per week over 3 and 8 weeks, respectively. In the LLLT group, 3 Joules of 904 nm wavelength laser was applied to 15 spots per knee (45 Joules/knee/session). The primary outcomes are pain during movement, at night and at rest (Visual Analogue Scale) and global pain (Knee injury and Osteoarthritis Outcome Score, KOOS) pain subscale. The secondary outcomes are KOOS disability and quality-of-life, analgesic usage, global health change, knee active range of motion, 30 s chair stand, maximum painless isometric knee extension strength, knee pain pressure threshold and real-time ultrasonography-assessed suprapatellar effusion, meniscal neovascularization and femur cartilage thickness. All the outcomes are assessed 0, 3, 8, 26 and 52 weeks post-randomization, except for global health change, which is only evaluated at completed ST. This study features the blinding of participants, assessors and therapists, and will improve our understanding of what occurs with the local pathophysiology, tissue morphology and clinical status of persons with KOA up to a year after the initiation of ST and a higher 904 nm LLLT dose than in any published trial on this topic.

Effect of low-level laser therapy on postoperative endodontic pain: An updated systematic review

OBJECTIVE

To evaluate the influence of low-level laser therapy (LLLT) on postoperative pain after endodontic treatment.

METHODS

The PICOS strategy was used to identify randomized clinical trials comparing low-level laser therapy and mock laser therapy to manage postoperative pain after endodontic treatment, retreatment, and endodontic surgery. An electronic search was performed in MEDLINE through PubMed, Web of Science, LILACS, Scopus and Cochrane Library, OpenGrey and Google Scholar. Quality assessment was performed using the Cochrane Collaboration's tool for assessing the risk of bias. The quality of evidence was rated on the basis of the GRADE approach.

RESULTS

Twelve studies were included in the qualitative synthesis. Within the 12 studies, 7 articles were classified as "low risk of bias," 4 studies were considered "unclear risk of bias" and 1 study was considered "high risk of bias." Six studies evaluated the postoperative pain after primary root canal treatment, two studies after root canal retreatment and four after periapical surgery. Most of the studies reported significantly less postoperative pain after LLLT in different time periods; two studies found no differences. The certainty of evidence was classified as low and very low to treatment / retreatment and endodontic surgery, respectively.

CONCLUSIONS

Based on the limited quality evidence, most of the included studies reported significantly less postoperative pain after LLLT. However, the lack of standardization in laser parameters, use of medications and the certainty of evidence classified as low and very low indicate the need for further studies.

The use of a multi-modal approach in the rehabilitation of a pre-operative grade 3 ACL tear in a world-level Poomsae athlete: a case report

OBJECTIVE

This case is designed to aid practitioners in understanding the potential role of multi-modal care with vibration rehabilitative exercise for a complete ACL tear in a high-level Poomsae athlete.

CASE PRESENTATION

A 16-year-old male world-class Poomsae athlete presented with a right ACL rupture and LCL sprain. An extensive clinical examination and imaging confirmed a right grade 3 ACL tear. Due to the complete tear and impending participation in World Championships, a pre-operative rehabilitation strategy was implemented with treatment modalities aimed to accelerate return-to-play.

SUMMARY

An appropriate clinical history and physical examination of the knee is required when instability is present. Imaging is indicated when testing criteria are positive. Clinicians should be aware that multiple therapies can each serve a role in conservative care to better suit patient demands, especially at high levels of sport. In the article, the author proposes a tailored protocol using vibration rehabilitative exercise, bracing, vibration therapy, neuromuscular electrical stimulation, and laser to improve healing and sport-specific outcomes.

Review on the Cellular Mechanisms of Low-Level Laser Therapy Use in Oncology

Photobiomodulation (PBM) using low-level laser therapy (LLLT) is a treatment that is increasingly used in oncology. Studies reported enhancement of wound healing with reduction in pain, tissue swelling and inflammatory conditions such as radiation dermatitis, oral mucositis, and lymphedema. However, factors such as wavelength, energy density and irradiation frequency influence the cellular mechanisms of LLLT. Moreover, the effects of LLLT vary according to cell types. Thus, controversy arose as a result of poor clinical response reported in some studies that may have used inadequately planned treatment protocols. Since LLLT may enhance tumor cell proliferation, these will also need to be considered before clinical use. This review aims to summarize the current knowledge of the cellular mechanisms of LLLT by considering its effects on cell proliferation, metabolism, angiogenesis, apoptosis and inflammation. With a better understanding of the cellular mechanisms, bridging findings from laboratory studies to clinical application can be improved.

Penetration depth study of 830 nm low-intensity laser therapy on living dog tissue

Background and Aim

Recent studies have shown that low-intensity laser therapy (LILT) enhances chronic wound healing, reduces pain, reduces inflammation, and improves post-operative rehabilitation. However, clinical outcomes in the veterinary use of LILT vary between different experimental studies. This is explained by improper laser parameter settings and limits of its penetration depth. This study aimed to investigate the penetration depth of 830 nm LILT on living dog tissue in different operating modes. This entailed continuous wave (CW) versus pulse wave (PW) and with contact versus non-contact techniques of the laser probe at different tissue-laser probe distances. The results can be applied for use in clinical practice.

Materials and Methods

Twenty-four dogs that had undergone abdominal surgery were included in this study. The laser parameters were set at 200 mW, fluence of 4 J/cm² and the laser power output denoted as mean output power (MOP) was measured by a power meter.

Results

The MOP of the 830 nm CW laser was significantly higher than the PW laser (p<0.05). The MOP of the contact technique was significantly greater than that of the non-contact technique in both CW and PW modes (p<0.05). The MOP through the skin tissue was between 16.09 and 18.60 mW (8.05-9.30%) for the contact technique and 8.73 and 19.36 mW (4.37-9.68%) for the non-contact technique. In the muscle-skin layer, the MOP was between 0.50 and 1.56 mW (0.25-0.78%) and the MOP was not detected using the non-contact technique with a 5 cm tissue-laser probe distance.

Conclusion

Our study indicates that 830 nm LILT (with laser parameter setting at 200 mW, fluence of 4 J/cm² for both contact and non-contact techniques, and tissue-laser probe distance up to 5 cm) was appropriate for treatments within 14 mm of depth. However, the use of 830 nm LILT for an application in which the target tissue is deeper than 14 mm may limit its positive effect.

Electromedical devices in wound healing management: a narrative review

Wound healing is the sum of physiological sequential steps, leading to skin restoration. However, in some conditions, such as diabetes, pressure ulcers (PU) and venous legs ulcers (VLU), healing is a major challenge and requires multiple strategies. In this context, some electromedical devices may accelerate and/or support wound healing, modulating the inflammatory, proliferation (granulation) and tissue-remodelling phases. This review describes some helpful electromedical devices including: ultrasonic-assisted wound debridement; electrotherapy; combined ultrasound and electric field stimulation; low-frequency pulsed electromagnetic fields; phototherapy (for example, laser therapy and light-emitting diode (LED) therapy); biophotonic therapies, and pressure therapies (for example, negative pressure wound therapy, and high pressure and intermittent pneumatic compression) The review focuses on the evidence-based medicine and adequate clinical trial design in relation to these devices.

The Effects of Whole-Body Photobiomodulation Light-Bed Therapy on Creatine Kinase and Salivary Interleukin-6 in a Sample of Trained Males: A Randomized, Crossover Study

Photobiomodulation therapy (PBMT) can be applied to the whole body as compared to the application of using single hand-held devices that isolate a smaller muscle area. The purpose of this study was to examine the effects of an acute dose of whole-body PBMT pre- and post-high-intensity resistance training on creatine kinase (CK) and salivary interleukin-6 (IL-6) in a sample of trained males. Twelve males (31 ± 8.3 years, 177.2 ± 5.4 cm, and 86.0 ± 7.5 kg) were part of a randomized, counterbalanced, cross-over design, whereby each participant performed a high-intensity resistance training session that consisted of the bench press, chin-up, and repeated sprints on two separate occasions. Each participant was assigned to either the PBMT or control condition on two separate weeks, with a 10-days washout period between the weeks. Creatine kinase was measured at baseline, 24, 48, and 72 h post-exercise. Salivary IL-6 was measured at baseline, 60, 90, and 120 min. A paired t-test showed no significant difference (p = 0.669) in the area under the curve (AUC) for CK during the PBMT (191.7 ± 48.3) and control conditions (200.2 ± 68.0). A Wilcoxon signed-rank test also showed no significant median difference (p = 0.155) in the AUC for salivary IL-6 during the PBMT (Mdn = 347.7) and control conditions (Mdn = 305.8). An additional Wilcoxon signed-rank test for CK percentage change from 24 to 72 h showed the PBMT condition (Mdn = −45%) to have a −18% median difference as compared to the control condition (Mdn = −41%). As such, whole-body PBMT does not significantly reduce the activity of salivary IL-6 or CK concentration during the 24 to 72-h recovery post-high-intensity resistance training.

Photobiomodulation in Endodontic, Restorative, and Prosthetic Dentistry: A Review of the Literature

Objective: To provide a review of the literature about the photobiomodulation therapy (PBMT) dental treatment protocols in endodontic, restorative, and prosthetic dentistry based on validated clinical studies published so far. More specifically, this study was carried out to carefully review therapeutic protocol of PBMT in clinical studies and their conclusions. Background data: The importance of using low-power lasers and photobiomodulation (PBM) is increasing in dentistry mainly due to their painless and noninvasive function. However, lack of sufficient clinical studies has led to unclear results regarding PBMT in dentistry, and also lack of an available precise protocol for clinicians. Moreover, scarcity of clinical studies in this area has made conduction of a precise systematic review study difficult. Methods: In our study, published clinical studies up to April 2019 were reviewed from library sources, Google Scholar, PubMed and Medline, Elsevier, Embase, Cochrane, Scopus, and Web of science (ISI). Inclusion criteria included those presented in clinical trials and case report/case series, language (English), and studies available in full text. Exclusion criterion was in vitro studies. Results: In general, findings of clinical studies have shown that PBMT can have a significant role in reducing postoperative dental pain, increasing depth of anesthesia, improving tooth hypersensitivity, reducing inflammation of the tissue, and helping wound healing. Conclusions: A review of clinical studies showed that the use of alternative or adjunctive PBMT is of great importance in controlling postoperative pain after endodontic treatments. In addition, evidence suggests that different parameters of light can be efficient in the treatment of tooth hypersensitivity. Nevertheless, lack of sufficient clinical studies and reliable results do not allow introducing a precise treatment protocol.

Photobiostimulation activity of different low-level laser dosage on masticatory muscles and temporomandibular joint in an induced arthritis rat model

This study aimed to investigate the anti-inflammatory effects of different dosage of low-level laser therapy (LLLT) in an experimental model of temporomandibular joint (TMJ) arthritis. One hundred male Wistar rats were used and divided into the following groups: CG, control group; AG, animals group with left TMJ arthritis induced by intra-articular injection of Complete Freund's adjuvant - CFA; LG5, LG10 and LG20 - animals with arthritis and treated with LLLT at doses 5, 10, and 20 J/cm², respectively. Morphological analysis was performed by TMJ histological sections stained with hematoxylin-eosin (HE), picrosirius (PSR), and toluidine blue (TB), as well as histomorphometric evaluation of cartilage, articular disc, and masticatory muscles. The amount of feed consumed within 3 weeks was evaluated, and biochemical analysis of TMJ tissues included measurement of sulfated glycosaminoglycans (GAGs), matrix metalloproteinases (MMPs) 2 and 9 zymography, and ELISA for cytokines IL-6, TNF-α, and IL-1β. Only the 20 J/cm² dose promoted higher feed intake compared to AG. On the other hand, all LLLT doses promoted better organization of articular disc collagen fibers, greater number of proteoglycans in articular cartilage, increased area and diameter of left lateral pterygoid fibers, reduced latent and active MMP 9 and 2 activity, and lower IL-1β concentration compared to AG. Considering the study limitations, it was observed that LLLT treatments were effective in protecting and tissue cleansing joint structures, accelerating tissue repair, especially at lower doses.

Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials

OBJECTIVES

Low-level laser therapy (LLLT) is not recommended in major knee osteoarthritis (KOA) treatment guidelines. We investigated whether a LLLT dose-response relationship exists in KOA.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Eligible articles were identified through PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database and Cochrane Central Register of Controlled Trials on 18 February 2019, reference lists, a book, citations and experts in the field.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We solely included randomised placebo-controlled trials involving participants with KOA according to the American College of Rheumatology and/or Kellgren/Lawrence criteria, in which LLLT was applied to participants' knee(s). There were no language restrictions.

DATA EXTRACTION AND SYNTHESIS

The included trials were synthesised with random effects meta-analyses and subgrouped by dose using the World Association for Laser Therapy treatment recommendations. Cochrane's risk-of-bias tool was used.

RESULTS

22 trials (n=1063) were meta-analysed. Risk of bias was insignificant. Overall, pain was significantly reduced by LLLT compared with placebo at the end of therapy (14.23 mm Visual Analogue Scale (VAS; 95% CI 7.31 to 21.14)) and during follow-ups 1-12 weeks later (15.92 mm VAS (95% CI 6.47 to 25.37)). The subgroup analysis revealed that pain was significantly reduced by the recommended LLLT doses compared with placebo at the end of therapy (18.71 mm (95% CI 9.42 to 27.99)) and during follow-ups 2-12 weeks after the end of therapy (23.23 mm VAS (95% CI 10.60 to 35.86)). The pain reduction from the recommended LLLT doses peaked during follow-ups 2-4 weeks after the end of therapy (31.87 mm VAS significantly beyond placebo (95% CI 18.18 to 45.56)). Disability was also statistically significantly reduced by LLLT. No adverse events were reported.

CONCLUSION

LLLT reduces pain and disability in KOA at 4-8 J with 785-860 nm wavelength and at 1-3 J with 904 nm wavelength per treatment spot.

PROSPERO REGISTRATION NUMBER

CRD42016035587.

The effect of red-to-near-infrared (R/NIR) irradiation on inflammatory processes

Introduction: Near-infrared (NIR) and red-to-near-infrared (R/NIR) radiation are increasingly applied for therapeutic use. R/NIR-employing therapies aim to stimulate healing, prevent tissue necrosis, increase mitochondrial function, and improve blood flow and tissue oxygenation. The wide range of applications of this radiation raises questions concerning the effects of R/NIR on the immune system. Methods: In this review, we discuss the potential effects of exposure to R/NIR light on immune cells in the context of physical parameters of light. Discussion: The effects that R/NIR may induce in immune cells typically involve the production of reactive oxygen species (ROS), nitrogen oxide (NO), or interleukins. Production of ROS after exposure to R/NIR can either be inhibited or to some extent increased, which suggests that detailed conditions of experiments, such as the spectrum of radiation, irradiance, exposure time, determine the outcome of the treatment. However, a wide range of immune cell studies have demonstrated that exposure to R/NIR most often has an anti-inflammatory effect. Finally, photobiomodulation molecular mechanism with particular attention to the role of interfacial water structure changes for cell physiology and regulation of the inflammatory process was described. Conclusions: Optimization of light parameters allows R/NIR to act as an anti-inflammatory agent in a wide range of medical applications.

Fractionated Irradiation in Photobiomodulation Therapy of Ankle Sprain

OBJECTIVE

The aim of this study was to test whether fractionated irradiation in photobiomodulation therapy enhances short-term recovery in patients with moderate severity ankle sprain.

DESIGN

Nineteen patients were randomly assigned to one of two groups: one group receiving photobiomodulation therapy combined with the standard rest, icing, compression, and elevation treatment, or a group receiving only standard treatment. Group 1 patients were irradiated using a laser system (635 nm, 15 mW) according to a double-fractionated irradiation scheme consisting of two sessions (4.5 and 9 J/cm) separated by a 30-min time interval. Short-term outcomes (reflectance, pain, and clinical outcomes) were assessed at baseline, 10 days, and 6 wks after treatment.

RESULTS

Reflectance data analysis showed significant changes in group 1 (P = 0.027). There was also an ankle function score improvement more in group 1 than in group 2, with a significant short-term effect (P = 0.011) but without significant long-term effects (P = 0.178). Compared with group 2, group 1 had an immediate effect on pain reduction, but no long-term effect (P = 0.074).

CONCLUSIONS

Combined with standard treatment, fractionated irradiation photobiomodulation therapy has been shown to have favorable short-term effects on the recovery of patients with ankle sprains, but its long-term effects should be improved.

Effect of 810 nm Near-Infrared Laser on Revascularization of Ischemic Flaps in Rats

OBJECTIVE

To investigate the effect of 810 nm near-infrared (NIR) laser on the revascularization of ischemic flaps.

BACKGROUND

It has long been proved that photobiomodulation therapy (PBMT) improves the blood supply of flaps. NIR laser improves the treatment of hypodermis-located lesions and of flap survival, but basic research on the use of 810 nm NIR laser for ischemic flap revascularization is still lacking.

MATERIALS AND METHODS

We prepared two symmetrical long random-pattern flaps on the backs of 60 rats. Each flap was 6 cm long, 1 cm wide, and 1 cm to the middle line. The flaps were divided into an irradiated flap group and an internal control group. The irradiated flaps underwent postoperative 810 nm laser therapy with the energy density of 11.30 J/cm² daily. The control flaps were covered by stainless steel to avoid laser irradiation. We observed the viability of the flaps. The flaps underwent Hematoxylin and Eosin (H&E) staining for the observation of histomorphology, immunohistochemical staining of factor VIII for the capillary count, α-smooth muscle actin for the small arterial count, and vascular endothelial growth factor for the integrated optical density (OD) of the positive stained color.

RESULTS

The irradiated flaps showed significantly better flap survival than the control flaps. H&E staining showed that the irradiated flaps had clear tissue structure and little inflammatory cell infiltration. The control flaps demonstrated comparatively worse results. Vascular endothelial growth factor staining showed that the difference in integrated OD between the irradiated flaps and the control flaps was not statistically significant. α-smooth muscle actin and factor VIII staining showed significantly greater numbers of arterioles and capillaries in the irradiated flaps than the control flaps after 4 days of irradiation.

CONCLUSIONS

PBMT with 810 nm NIR laser could enhance ischemic flap revascularization and increase flap viability.

Photobiomodulation Therapy in Veterinary Medicine: A Review

Laser therapy, or photobiomodulation, has rapidly grown in popularity in human and veterinary medicine. With a number of proposed indications and broad, sometimes anecdotal, use in practice, research interest has expanded aimed at providing scientific support. Recent studies have shown that laser therapy alters the inflammatory and immune response as well as promotes healing for a variety of tissue types. This review will cover the history of the modality, basic principles, proposed mechanisms of action, evidence-based clinical indications, and will guide the practitioner through its application in practice.

Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment

Low-level laser therapy (LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals (12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group (LG) or a placebo group (PG) (1:1). The LG received LLLT (810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm^–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale (NRS) of pain, pressure pain thresholds (PPTs), cold detection thresholds (CDTs), warmth detection thresholds (WDTs), cold pain thresholds (CPTs), and heat pain thresholds (HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance (ANOVA). The NRS pain scores were significantly lower in the LG group (P = 0.01). The CDTs, CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG (P < 0.033). The parameters tested also showed significantly less sensitivity on the non-treatment side of the LG compared to that of the PG (P < 0.043). There were no differences between the groups for any quantitative sensory testing (QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment. Further clinical applications are suggested.

Repeated applications of low-level laser therapy during and after orthodontic procedures could help reduce pain and discomfort. Many orthodontic patients experience pain in the hours and days following treatment, which impacts on treatment participation. Wenjing Chen at Nanjing Medical University and co-workers assessed whether low-level laser therapy (LLLT) can reduce pain and sensitivity in teeth and surrounding tissues. They divided 40 patients into two groups; one was given repeated LLLT in the hours and days following procedures, while the other group received a placebo course. They tested both groups for sensitivity to stimuli including heat and pressure, in the mouth and on the hands. LLLT significantly reduced pain in the mouth relative to the placebo group. No differences were found in tests on the hands, suggesting LLLT works as a targeted analgesia.

Can photobiomodulation associated with implantation of mesenchymal adipose-derived stem cells attenuate the expression of MMPs and decrease degradation of type II collagen in an experimental model of osteoarthritis?

This study aimed to determine whether photobiomodulation therapy (PBMT) could improve the bioavailability and chondroprotective benefits of mesenchymal stem cells injected into the knees of rats used as an experimental model of osteoarthritis (OA) as well as reduce the expression of matrix metalloproteinases (MMPs) and degradation of type II collagen (COL2-1) in the cartilage. Adipose-derived stem/stromal cells (ADSCs) were collected from three male Fischer 344 rats and characterized by flow cytometry. Fifty female Fischer 344 rats were distributed into five groups of 10 animals each. These groups were as follows: control, OA, OA PBMT, OA ADSC, and OA ADSC PBMT. OA was induced in the animals using a 4% papain solution. Animals from the OA ADSC and OA ADSC PBMT groups received an intra-articular injection of 10 × 10⁶ ADSCs and were treated with PBMT by irradiation (wavelength: 808 nm, power: 50 mW, energy: 42 J, energy density: 71.2 J/cm², spot size: 0.028). Euthanasia was performed 7 days after the first treatment. The use of PBMT alone and the injection of ADSCs resulted in downregulation of pro-inflammatory cytokines and MPs in cartilage compared to the OA group. PBMT and ADSCs caused upregulation of tissue inhibitors of MPs 1 and 2 and mRNA and protein expression of COL2-1 in cartilage compared to the OA group. The intra-articular injection of ADSCs and PBMT prevented joint degeneration resulting from COL2-1 degradation and modulated inflammation by downregulating cytokines and MMPs in the OA group.

Ultrasound plus low-level laser therapy for knee osteoarthritis rehabilitation: a randomized, placebo-controlled trial

This study evaluated the synergistic effects of ultrasound (US) and low-level laser therapy (LLLT) with or without therapeutic exercises (TE) in women with knee osteoarthritis. Forty-two Caucasian women with knee osteoarthritis were allocated into three groups: (1) the placebo group who did not perform TE, but the prototype without emitting light or ultrasonic waves was applied, (2) the US + LLLT group in which only the prototype was applied and (3) the TE + US + LLLT group that performed TE before the prototype was applied. However, 35 women completed the full clinical trial. Pressure pain thresholds (PPT) using an algometer and functional performance during the sit-to-stand test were carried out. The average PPT levels increased for US + LLLT (41 ± 9 to 54 ± 15 N, p < 0.01) and TE + US + LLLT (32 ± 8 to 45 ± 9 N, p < 0.01) groups. The number of sit-to-stands was significantly higher for all groups. However, the change between pre-treatment and post-treatment (delta value) was greater for the US + LLLT (4 ± 1) and TE + US + LLLT groups (5 ± 1) than for the placebo group (2 ± 1) with a significant intergroup difference (p < 0.05). This study showed reduced pain and increased physical functionality after 3 months of US + LLLT with and without TE.

Photobiomodulation versus light-emitting diode (LED) therapy in the treatment of temporomandibular disorder: study protocol for a randomized, controlled clinical trial

BACKGROUND

Temporomandibular disorder (TMD) is described as a subgroup of orofacial pain with a set of signs and symptoms that involve the temporomandibular joint, masticatory muscles, ears, and neck. TMD can occur unilaterally or bilaterally and approximately 70% of the population is affected with at least one sign. The disorder progresses with orofacial pain, muscle pain involving the masticatory and cervical muscles, joint noises (clicks and pops), joint block, mandibular dysfunction, and headache. The etiology can be abnormal occlusion and/or posture, trauma involving local tissues, repetitive microtrauma, parafunctional habits, and an increase in emotional stress. Studies have demonstrated that phototherapy is an efficient option for the treatment of TMD, leading to improvements in pain and orofacial function.

METHODS

The aim of the proposed study is to compare the effects of two sources of photobiomodulation in individuals with TMD. A randomized, controlled, double-blind, clinical trial is proposed, which will involve 80 individuals aged 18-65 years allocated to either a laser group or light-emitting diode (LED) group submitted to 12 sessions of phototherapy. The Research Diagnostic Criteria for TMDs will be used to evaluate all participants. Pain will be measured using the visual analog scale and maximum vertical mandibular movement will be determined with the aid of digital calipers.

DISCUSSION

This study compares the effects of two modalities of laser therapy on the pain and orofacial function of patients with TMD dysfunction. Photobiomodulation and LED therapy are treatment options for reducing the inflammatory process and pain as well as inducing the regeneration of the target tissue.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03257748 . Registered on 8 August 2017.