The efficacy of laser therapy in wound repair: a meta-analysis of the literature

Clinical efficacy and pain control of diode laser-assisted flap surgery in the treatment of chronic periodontitis:A systematic review and meta-analysis

Objective

To assess the diode laser-assisted periodontal flap surgery's clinical effectiveness and postoperative pain management in treating chronic periodontitis, and to offer evidence-based medical justification for the procedure's clinical use.

Data sources and study selection

In this study, a computer combined with manual search was used to search for articles on diode laser-assisted periodontal flap surgery for the treatment of chronic periodontitis published from the establishment of the database to September 2023. The databases searched included China Academic Journal Full Text Database (CNKI), China Biomedical Literature Database (CBM), Chinese Science and Technology Journal Database (VIP), Wanfang Database, PubMed, Web of science, Cochrane Library, Embase, and Scopus. Two researchers independently performed the screening and study selection, following the inclusion and exclusion standards to extract basic information and required data. Meta-analysis of the included literature was performed using Revman V5.4 software.

Result

Thirteen articles were analyzed. Meta-analysis showed that the use of the diode laser was effective in reducing patients' probing pocket depth (PPD) at 3 and 6 months postoperatively (3 months: MD = -0.46, 95 % CI = [-0.89, -0.03], P = 0.04; 6 months: MD = -0.35, 95 % CI = [-0.63, -0.06], P = 0.02), was able to effectively improve 3 month clinical attachment level (CAL) (MD = -0.36, 95 % CI = [-0.66, -0.06], P = 0.02), and was able to promote wound healing and reduce patients' early postoperative pain (MD = 0.67, 95 % CI = [0.01, 1.32], P = 0.05; MD = -1.67, 95 % CI = [-2.23, -1.00], and P < 0. 001), while for gingival index (GI), the use of diode laser did not have a significant effect.

Conclusions

The available evidence suggests that the use of a diode laser adjunct is effective in reducing PPD, improving CAL, promoting wound healing, and reducing early postoperative pain in patients compared with flap application alone; however, for GI, diode lasers did not show any improvements.

Clinical significance

Periodontal flap surgery fails to eliminate microorganisms from the soft tissue wall, potentially leading to recolonization, reinfection, and accompanying side effects such as pain and swelling. The use of a diode laser reduces PPD, improves CAL, and relieves early postoperative pain.

Performance of multiple therapeutic approaches for palatal wound healing after soft tissue graft removal - an overview of systematic reviews

OBJECTIVE

To overview the literature to answer the following question: "What is the performance of different therapies on wound healing and postoperative discomfort after palatal ASTG removal?"

METHODS

SRs that evaluated the wound healing (WH), postoperative pain, bleeding, and analgesic consumption of patients submitted to de-epithelialized/free gingival grafts (FGG) or subepithelial connective tissue grafts (SCTG) removed from the palate were included. The searches were conducted on six white and two gray databases up to December 2023. Methodological quality was evaluated through AMSTAR 2. The synthesis of results was described as a narrative analysis.

RESULTS

Ten SRs (involving 25 randomized clinical trials) related to low-level laser therapy (LLLT) (3), platelet-rich fibrin (PRF) (4), cyanoacrylate tissue adhesives (CTA) (2), and ozone therapy (OT) (1) were included in this overview. All techniques demonstrated improvements in WH. LLT, PRF, and CTA reduced pain and analgesic consumption. PRF and CTA reduced bleeding. Regarding methodological quality, the SRs were classified as critically low (2), low (5), moderate (2), or high quality (1).

CONCLUSIONS

In SRs related to LLLT, PRF, CTA, and OT, the use of different therapies after palatal ASTG removal improved WH and postoperative discomfort. Due to the studies' low methodological quality and high heterogeneity, data should be interpreted with caution.

CLINICAL RELEVANCE

The present overview compiles the evidence of SRs related to different therapies for WH and patients' postoperative experience and reveals that different treatments can significantly improve the clinical outcomes of patients who require ASTG removal for periodontal or peri-implant surgeries.

REGISTRATION

PROSPERO registration number: CRD42022301257.

Effects of Short-, Medium-, and Long-Term Treatment Using Photobiomodulation Therapy Combined with Static Magnetic Field in Aging Rats

(1) Background: We investigated the detrimental and protective effects of short-, medium, and long-term treatment with different doses of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) during the aging process. (2) Methods: Rats were treated for 15, 30, and 60 weeks with 1, 3, 10, and 30 J of PBMT-sMF or a placebo control. In addition, eight young rats were not subjected to any procedure or treatment and were euthanized at six weeks old. Skin, muscle, bone, kidney, liver, and blood samples were analyzed. (3) Results: No differences between the groups in the morphology of the skin, muscle, and bone was observed. Glutamic pyruvic transaminase levels were increased in the placebo group after 30 and 60 weeks. Glutamic oxaloacetic transaminase levels were also increased in the placebo group after 30 weeks. An increase in creatinine in the PBMT-sMF 3, 10, and 30 J groups compared with that in the young control group was observed. No significant difference in urea levels between the groups was noted. Vascular endothelial growth factor increased in the PBMT-sMF 10 and 30 J groups after 15 weeks of treatment and in the PBMT-sMF 3 J after 60 weeks. Finally, vascular endothelial growth factor decreased in the PBMT-sMF 30 J group after 30 weeks of treatment. (4) Conclusions: PBMT-sMF did not have detrimental effects on the skin, muscle, bone, kidney, or liver after short-, medium-, and long-term treatments in aging rats. In addition, PBMT-sMF may have protective effects on the muscle tissue in aging rats after short- and long-term treatment.

Effect of low-level laser therapy in wound healing of primary molar teeth extraction

INTRODUCTION

Tooth extraction in children requires attention to wound healing and pain management, which are influenced by patient-related factors and behavioral guidance.

AIM OF THE STUDY

The study aimed to evaluate the effect of LLLT on healing sockets in pediatric patients with bilateral primary molar teeth extraction and determine its impact on pain management.

METHODS

6-10 years of age, systemically healthy, and with atraumatic extraction indications of bilateral primary molar teeth were included in the study (n = 40). In the first session, randomly selected teeth were extracted under local anesthesia. In the control group, only clot formation in the socket was observed and photographed. The other group extractions were performed 2 weeks later. The low-level laser therapy (LLLT) group was treated with a 980 nm wavelength, in a continuous emission mode, 0.5 W power, 300 J of energy, 400 µm tip, 60 s diode laser and photographed. Nonepithelialized surface measurements were performed using ImageJ. Pain assessment was performed using the Wong-Baker Pain Scale. Statistical analyses were performed using SPSS software.

RESULTS

There was a statistically significant difference between the groups in the Wong-Baker values in 3rd day (p < 0.05). In soft tissue healing on the 3rd and 7th day, the nonepithelialized surface of the laser socket was smaller than that of the control group, and the measurement results were found to be statistically significant (p < 0.05).

CONCLUSION

Although LLLT was not found to be very effective in reducing postoperative discomfort after extraction of primary molars, it provided better wound healing in extraction sockets.

Histological, Physiological and Biomechanical Effects of Low-Level Laser Therapy on Tendon Healing in Animals and Humans: A Systematic Review

Low-level Laser Therapy (LLLT) was widely used in clinical practice for tendon disorders. However, the underlying mechanisms and effectiveness of LLLT in treating tendon injury remain unclear. Therefore, the present study was conducted aiming to summarize the evidence regarding the histological, physiological, and biomechanical effects of LLLT on tendon healing in animal and human models. Four databases were searched for relevant literature. Four independent reviewers screened abstracts and full-text articles, extracted relevant data, evaluated the risk of bias, and quantified the quality of evidence. Database searches yielded 1400 non-duplicated citations. Fifty-five studies were included (50 animal and five human studies). Animal studies revealed that LT had stimulating effects on collagen organization, collagen I and collagen II formation, matrix metalloproteinase (MMP)-8, transforming growth factor β1, vascular endothelial growth factor, hydroxyproline, maximum load, maximum elongation before breaking, and tendon stiffness. However, LLLT had inhibitory effects on the number of inflammatory cells, histological scores, relative amount of collagen III, cyclooxygenase-2, prostaglandin E2 (PGE2), interleukin-6, tumor necrosis factor-α, MMP-1, and MMP-3. Although one human study found that LLLT reduced the concentration of PGE2 in peritendinous tissue of the Achilles tendon, other human studies revealed that the effects of LLLT on the physiology and biomechanics of human tendons remained uncertain. LLLT facilitates tendon healing through various histological, physiological, and biomechanical effects in animal models. Only post-LLLT anti-inflammatory effects were found in human studies.

Effectiveness of photodynamic therapy on clinical and biomarker related periodontal parameters and oral health related quality of life (OHRQoL) in Parkinson's disease patients with stage III periodontitis

AIMS

To evaluate the clinical, radiographic, immune modulatory biomarkers and quality of life with the application of photodynamic therapy (PDT) as an adjunctive treatment to dental scaling and root planing (SRP) in patients with chronic periodontitis and Parkinson's disease.

METHODOLOGY

Individuals who had a confirmed diagnosis of stage III periodontitis and stage 4 Parkinson's disease according to Hoehn and Yahr scale were involved in this study. The participants were divided into two groups: Group SRP (n = 25) received traditional dental scaling procedure including full-mouth debridement and disinfection, and Group PDT + SRP (n = 25) received both traditional cleaning procedures along with adjunctive chloro‑aluminum phthalocyanine (CAPC) gel (0.005% concentration) mediated PDT. CAPC photosensitizer was activated using a diode laser (wavelength=640 nm, energy=4 J, 150 mW power, and overall power density of 300 J/cm2) for 60 s. The study measured clinical parameters such as plaque score (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and radiographic alveolar bone loss (ABL). Proinflammatory cytokine levels such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) and oral health related quality of life were also assessed.

RESULTS

The mean age of patients in Group SRP was 73.3 years, while the mean age in Group PDT + SRP was 71.6 years. The PDT + SRP group showed a significant reduction in all clinical parameters at 6 and 12 months compared to the SRP group alone (p < 0.05). IL-6 and TNF-α levels were significantly reduced in the PDT + SRP group at 6 months compared to the SRP group alone (p < 0.05). However, at 12 months, both groups showed comparable TNF-α levels. The results showed that Group PDT + SRP had significantly lower OHIP scores compared to Group SRP, with a mean difference of 4.55 (95% confidence interval [CI]: 1.98 to 7.12) (p < 0.01).

CONCLUSION

Combined SRP with PDT showed significant improvement compared to SRP alone in terms of clinical parameters, cytokine levels, and oral health-related quality of life in individuals diagnosed with stage III periodontitis associated with Parkinson's disease.

A Holistic Perspective on How Photobiomodulation May Influence Fatigue, Pain, and Depression in Inflammatory Bowel Disease: Beyond Molecular Mechanisms

BACKGROUND

Numerous mechanisms, mostly molecular, have been tested and proposed for photobiomodulation. Photobiomodulation is finding a niche in the treatment of conditions that have no gold-standard treatment or only partially effective pharmacological treatment. Many chronic conditions are characterised by symptoms for which there is no cure or control and for which pharmaceuticals may add to the disease burden through side effects. To add quality to life, alternate methods of symptom management need to be identified.

OBJECTIVE

To demonstrate how photobiomodulation, through its numerous mechanisms, may offer an adjunctive therapy in inflammatory bowel disease. Rather than considering only molecular mechanisms, we take an overarching biopsychosocial approach to propose how existing evidence gleaned from other studies may underpin a treatment strategy of potential benefit to people with Crohn's disease and ulcerative colitis.

MAIN FINDINGS

In this paper, the authors have proposed the perspective that photobiomodulation, through an integrated effect on the neuroimmune and microbiome-gut-brain axis, has the potential to be effective in managing the fatigue, pain, and depressive symptoms of people with inflammatory bowel disease.

Evaluation of Photobiomodulation and Boldine as Alternative Treatment Options in Two Diabetic Retinopathy Models

Diabetic retinopathy causes progressive and irreversible damage to the retina through activation of inflammatory processes, overproduction of oxidative species, and glial reactivity, leading to changes in neuronal function and finally ischemia, edema, and hemorrhages. Current treatments are invasive and mostly applied at advanced stages, stressing the need for alternatives. To this end, we tested two unconventional and potentially complementary non-invasive treatment options: Photobiomodulation, the stimulation with near-infrared light, has shown promising results in ameliorating retinal pathologies and insults in several studies but remains controversial. Boldine, on the other hand, is a potent natural antioxidant and potentially useful to prevent free radical-induced oxidative stress. To establish a baseline, we first evaluated the effects of diabetic conditions on the retina with immunofluorescence, histological, and ultrastructural analysis in two diabetes model systems, obese LepR^db/db mice and organotypic retinal explants, and then tested the potential benefits of photobiomodulation and boldine treatment in vitro on retinal explants subjected to high glucose concentrations, mimicking diabetic conditions. Our results suggest that the principal subcellular structures affected by these conditions were mitochondria in the inner segment of photoreceptors, which displayed morphological changes in both model systems. In retinal explants, lactate metabolism, assayed as an indicator of mitochondrial function, was altered, and decreased photoreceptor viability was observed, presumably as a consequence of increased oxidative-nitrosative stress. The latter was reduced by boldine treatment in vitro, while photobiomodulation improved mitochondrial metabolism but was insufficient to prevent retinal structural damage caused by high glucose. These results warrant further research into alternative and complementary treatment options for diabetic retinopathy.

Transcriptome analysis of the effects of polarized photobiomodulation on human dermal fibroblasts

BACKGROUND

Photobiomodulation (PBM), the therapeutic use of light, is used to treat a myriad of conditions, including the management of acute and chronic wounds. Despite the presence of clinical evidence surrounding PBM, the fundamental mechanisms underpinning its efficacy remain unclear. There are several properties of light that can be altered in the application of PBM, of these, polarization-the filtering of light into specified plane(s)-is an attractive variable to investigate.

AIMS

To evaluate transcriptomic changes in human dermal fibroblasts in response to polarized PBM.

RESULTS

A total of 71 Differentially Expressed Genes (DEGs) are described. All DEGs were found in the polarized PBM group (P-PBM), relative to the control group (PC). Of the 71 DEGs, 10 genes were upregulated and 61 were downregulated. Most DEGs were either mitochondrial or extracellular matrix (ECM)-related. Gene Ontology (GO) analysis was then performed using the DEGs from the P-PBM vs. PC group. Within biological processes there were 95 terms found (p < 0.05); in the molecular function there were 18 terms found (p < 0.05); while in the cellular component there were 32 terms enriched (p < 0.05). A KEGG pathways analysis was performed for the DEGs found in the P-PBM vs. PC group. This revealed 21 significantly enriched pathways (p < 0.05). Finally, there were 24 significantly enriched reactome pathways when comparing the DEGs of the P-PBM vs. PC groups (p < 0.05).

DISCUSSION AND CONCLUSIONS

The P-PBM DEGs were almost always down regulated compared to the comparator groups. This may be explained by the P-PBM treatment conditions decreasing the amount of cellular stress, hence causing a decreased mitochondria and ECM protective response. Alternatively, it could point to an alternate mechanism, outside the mitochondria, by which PBM exerts its effects. Additionally, PBM appears to have a more widespread effect on the mitochondria than previously thought, opening up many new avenues of investigation in the process.

Periodontal, Microbiological, and Proinflammatory Cytokines Levels in Fixed Orthodontics Patients Treated with Photodynamic Therapy Adjunct to Full Mouth Scaling

Objective: To assess the efficiency of photodynamic therapy (PDT) adjunct to full mouth scaling (FMS) in improving periodontal, microbiological, and proinflammatory cytokines levels in patients undergoing fixed orthodontics treatment (FOT). Materials and methods: The study recruited 60 teenage patients who were undergoing FOT. All the patients were arbitrarily divided into two groups: Group 1, FMS +PDT and Group 2, FMS alone. Plaque scores (PS), bleeding on probing (BOP), and probing depth (PD) were assessed. Levels of biomarkers interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) using enzyme-linked immunosorbent assay were evaluated. Samples were collected from gingival plaque for estimation of Prevotella intermedia and Porphyromonas gingivalis load. All measurements were completed at three intervals baseline, 4th week, and 8th week. Post Hoc corrections and intergroup comparisons were examined using Student's t-test and Bonferroni correction. To find differences between repeated follow-ups, analysis of variance (ANOVA) multiple rank tests were used. Results: At baseline, all the gingival parameters displayed comparable outcomes between patients of Group 1 and Group 2 (p > 0.05). However, at 4 and 8 weeks of follow-up, PS and BOP among tested groups exhibited significantly lower values than baseline (p < 0.001). At 8 weeks, there was a significant difference in PS between the two groups tested. Moreover, at 4 and 8 weeks, BOP revealed a significant difference between the groups. PD remains comparable with baseline at follow-up visits (p > 0.05). A significant decrease in IL-6 and TNF-α levels was observed in both investigated groups at 4 and 8 weeks of baseline. Moreover, it was identified that P. intermedia and P. gingivalis were reduced significantly at 4 weeks. Moreover, a significant difference existed between both Group 1 and Group 2 at 4 and 8 weeks of recall visit (p < 0.05). Conclusions: The use of photodynamic treatment adjuvant to FMS aids in improving periodontal parameters and cytokines levels.

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.

Photobiomodulation in dental implant stability and post-surgical healing and inflammation. A randomised double-blind study

BACKGROUND

The aim of this randomized clinical trial was to evaluate the effect of diode laser photobiomodulation (PBM) on post-surgical healing, inflammation and implant stability.

METHODS

Forty dental implants were inserted into 13 patients. The implants were randomly divided into two groups. The test group (PBM+) underwent two sessions of PBM (combined diode laser of 630 and 808 nm), the first of which after surgery, and the second, 7 days after the surgical procedure. The control group (PBM-) received simulated laser treatment. The implant stability quotient (ISQ) was determined immediately after the surgical procedure, and 7 days, 4 and 8 weeks later. Post-surgical inflammation was assessed following the criteria described by Bloemen and Cols. Healing was calculated using the healing index (HI).

RESULTS

No differences were found in terms of the mean values of implant stability between the test and control groups over time. Only two of the implants (18.2%) from the PBM- group were classified with the maximum healing index (HI = 5), whereas in the PBM+ group, nine implants (45%) were classified with the aforementioned index (P < 0.0001). Using the logistic regression, it was determined that the non-application of the laser in the PBM- group caused an OR of 4.333 times of presenting inflammation (IC95% 1.150-16.323; P = 0.030).

CONCLUSIONS

The application of 808 nm infra-red laser for bone tissue, and 630 nm for mucosal tissue in two sessions is considered to be an effective way of reducing inflammation and improving early healing. More studies are needed to confirm these results.

Evaluating the Effect of Low Power Diode Laser 806 nm on the Healing of Unilateral Cleft Lip Scar: An Open-Label Comparative Study

OBJECTIVE

To investigate the effect of laser bio-modulation irradiation therapy on the scar after surgical correction of unilateral cleft lip.

DESIGN

a comparative, open-label study.

SETTING

we conducted the study in a university based tertiary hospital that recruited early wound healers of unilateral cleft lip correction.

PATIENTS

Eighty patients were divided into two groups: In study's group, patients undergo laser bio-modulation irradiation (n = 60); in the control group, patients were followed-up without intervention (n = 20).

INTERVENTION

In the study's group, patients underwent low-power diode Laser with wavelength of 806 nm and power of 100 mw.

MAIN OUTCOME

The change in the scar of cleft lip patients, which was assessed by clinical examination and ultrasound.

RESULTS

The median pigmentation score was significantly lower in the laser group (median = 1; IQR = 1-2) than the control group (median 2; IQR 1-3), with p-value of <0.001. Likewise, the median height score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 1.5; IQR 1.5-2), with p-value of 0.001. The median pliability score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 2.5; IQR 1-3), with p-value of <0.001. Finally, the median vascularity score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 1.5; IQR 1-2), with p-value of <0.001.

CONCLUSION

laser bio-modulation irradiation therapy demonstrates a potential efficacy in managing the hypertrophic scars after surgical repair of unilateral cleft lip.

A transient photoactivation of epidermal stem cells by femtosecond laser promotes skin wound healing

Wound healing is a long-term complex process, in which epidermal stem cells (EPSCs) in epidermis of skin have been found to play an essential role in it. We develop a noninvasive method to activate EPSCs in skin in vivo to promote wound healing, based on a microscopic system to enable a sequential frame-by-frame scanning of a femtosecond laser at 800 nm to the predefined skin region for a single time for 16 seconds. The laser is tightly focused on a submicron spot and localized in the epidermis, and scans point by point to activate EPSCs there. The density and stemness of EPSCs are significantly enhanced for at least 60 hours after the single-time transient photoactivation. We demonstrate this method works in a skin wound mouse model. Our results provide an optical method for in vivo EPSC activation and hold good potential in wound healing.

Anti-inflammatory effect of green photobiomodulation in human adipose-derived mesenchymal stem cells

Photo biomodulation (PBM) as a non-invasive and safe treatment has been demonstrated the anti-inflammatory potential in a variety of cell types, including stem cells. However, further investigations using different laser parameters combined with more accurate methods such as quantitative measurement of inflammatory gene expression at the mRNA level are still necessary. The aim of this study was to evaluate the effect of 532 nm green laser on cell proliferation as well as expression of inflammatory genes in human adipose-derived mesenchymal stem cells (hADMSCs) using RNA sequencing (RNA-seq) technique and confirmatory RT-PCR. hADMSCs were cultured in DMEM low glocuse medium with 10% fetal bovine serum until the fourth passage. Cultured cells were divided in two groups: control group (no laser irradiation) and laser group, irradiated with 532 nm laser at 44 m J/cm² with an output power of 50 mW and a density of 6 mW/cm², every other day, 7 s each time. The cell viability was assessed using MTT assay 24 h after each irradiation on days 3, 5, and 7 after cell seeding, followed by performing RNA-seq and RT-PCR. The MTT assay showed that PBM increased cell proliferation on day 5 after irradiation compared to day 3 and decreased on day 7 compared to day 5. In addition, gene expression analysis in hADMSCs using RNA-seq revealed down-regulation of inflammatory genes including CSF2, CXCL2, 3, 5, 6, 8, and CCL2, 7. These results indicate that 532 nm PBM with the parameters used in this study has a time-dependent effect on hADMSCs proliferation as well as anti-inflammatory potential.

The effects of polarized photobiomodulation on cellular viability, proliferation, mitochondrial membrane potential and apoptosis in human fibroblasts: Potential applications to wound healing

Photobiomodulation (PBM) is a widely used therapeutic intervention used to treat several chronic conditions. Despite this, fundamental research underpinning its effectiveness is lacking, highlighted by the lack of a definitive mechanism of action. Additionally, there are many treatment variables which remain underexplored, one of those being the effect of polarization the property of light that specifies the direction of the oscillating electric field. When applied to PBM, using linearly polarized light, when compared to otherwise identical non-polarized light, may enhance its biological efficacy. As such, we investigated the potential biological effects of polarized PBM when compared to non-polarized and non-irradiated controls in the domains of cellular viability, proliferation, apoptosis and mitochondrial membrane potential (ΔΨ) within cells exposed to oxidative stress. It was noted that polarized PBM, when compared to non-polarized PBM and non-irradiated controls, demonstrated mostly increased levels of cellular proliferation and ΔΨ, whilst decreasing the amount of cellular apoptosis. These results indicate that polarization may have utility in the clinical application of PBM. Future research is needed to further elucidate the underpinning mechanisms of PBM and polarization.

A, Prakash P, Bahammam SA, Bahammam MA, Almarghlani A, Assaggaf M, Kamil MA, Subramanian S, Balaji TM, Patil S. The Efficacy of Low-Level Laser Therapy Combined with Single Flap Periodontal Surgery in the Management of Intrabony Periodontal Defects: A Randomized Controlled Trial

This study aimed at assessing the clinical outcomes of the Single Flap Approach (SFA) with the additional use of Low-level laser therapy (LLLT). The defects were treated as per the principles of SFA, whereby 20 defects received only SFA (control group) and 20 defects received additional LLLT for bio stimulation/bio modulation (test group). Stable primary closure of the flaps was obtained with vertical internal mattress sutures. Plaque indices (FMPS), clinical attachment levels (CAL), probing pocket depth (PPD), and gingival bleeding scores (FMBS) were calculated at baseline, and at the 3rd and 6th months in both groups. An EHI score of 1 was observed at all sites except for two, where a score of 2 in the control group at week 2 was observed. In the test group, the PPD reduction at 6 months was 3.60 ± 0.95 and in the control group it was 3.75 ± 0.91 mm. CAL gain at 6 months was 2.70 ± 1.36 mm and 3.45 ± 1.2 mm in the test group and showed no statistical significance. These data suggested the positive effect of LLLT over CAL gain; thus, LLLT may be combined with SFA to potentially enhance the early wound healing and higher clinical outcomes in terms of increase in CAL and decrease in PPD.

Open flap debridement compared to repeated applications of photodynamic therapy in the treatment of residual pockets. A randomized clinical trial

BACKGROUND

The aim of the present study was to compare repeated applications of antimicrobial photodynamic therapy (aPDT) to open flap debridement (OFD) in the treatment of residual periodontal pockets in non-furcation sites.

METHODS

Forty-six subjects with a diagnosis of Stage III or IV Grade C periodontitis, that had been previously treated, participated in the study.  Residual pockets were divided between two groups: 1) aPDT group: received ultrasonic periodontal debridement followed by immediate application of aPDT, and repeated on1st, 2nd, 7th and 14th days; and 2) OFD group: treated by modified papilla preservation technique, where granulation tissue and visible calculus were removed with hand curettes and an ultrasonic device. Clinical, immunological and microbiological parameters were evaluated before and after treatment.

RESULTS

Both treatments were effective reducing clinical parameters of disease. OFD resulted in a greater mean probing pocket depths (PPD) reduction in deep pockets (p = 0.001). However, aPDT resulted in a lower occurrence of gingival recession (GR), dentin hypersensitivity and analgesic intake. Reduction in Porphyromonas gingivalis was observed in both groups. Only the OFD group had a significant reduction in Aggregatibacter actinomycetemcomitans. aPDT group had greater increase in IL-10 levels and a greater reduction of IL-1β at 14 days when compared to the OFD group (p<0.05).

CONCLUSION

OFD was superior in reducing PPD in deep pockets compared to the aPDT. However, OFD resulted in greater GR.  Both treatments lowered P. gingivalis levels but only OFD reduced levels of A. actinomycemtemcomitans. This article is protected by copyright. All rights reserved.

Optimization of photo-biomodulation therapy for wound healing of diabetic foot ulcers in vitro and in vivo

Unclear optical parameters make photo-biomodulation (PBM) difficult to implement in diabetic foot ulcer (DFU) clinically. Here, 12 wavelengths (400-900 nm) were used to conduct PBM to heal DFU wounds in vitro and in vivo. PBM at 10 mW/cm² and 0.5-4 J/cm² with all 12 wavelengths promoted proliferation of diabetic wound cells. In a mimic DFU (mDFU) rat model, PBM (425, 630, 730, and 850 nm, and a combination light strategy) promoted mDFU healing. The positive cell proliferation, re-epithelialization, angiogenesis, collagen synthesis, and inflammation were possible mechanisms. The combination strategy had the best effect, which can be applied clinically.

Effect of diode laser as an adjunct to open flap debridement in treatment of periodontitis – A randomized clinical trial

Background:

The goals of periodontal therapy are to prevent the disease, arrest the disease progression, and regeneration of lost periodontium. Diode laser gained popularity in periodontal practice with a wide range of potential benefits.

Aim:

This study aims to evaluate and compare the clinical effects of laser-assisted open flap debridement (OFD) versus conventional OFD for the periodontitis treatment.

Materials and Methods:

A split-mouth, randomized clinical trial was conducted on fifteen participants with periodontitis having probing pocket depths (PPD) ≥5 mm. A total of 30 sites, two sites in each patient, were randomly divided into two groups. Group A received conventional OFD, and Group B received laser-assisted OFD. The assessment of PPD, relative attachment level (RAL), modified sulcular bleeding index (mSBI) was done at baseline, 3 months, and 6 months. Wound healing index (WHI) was assessed at 3^rd and 7^th day postsurgery, patient response to pain using visual analog scale (VAS) was assessed immediately, 1 day, and 1 week after surgery.

Results:

The results revealed a significant reduction in PPD, mSBI, and gain in RAL within the groups from baseline to 3 months and 6 months. Intergroup comparison showed a significant difference in PPD, RAL, mSBI, WHI and VAS scores.

Conclusions:

The use of 980 nm diode laser provided additional benefits over conventional flap therapy.

Efficacy of Photobiomodulation and Vitamin D on Odontogenic Activity of Human Dental Pulp Stem Cells

Introduction: The regeneration of dental pulp tissue using human dental pulp stem cells (HDPSCs) has attracted increasing attention in recent years. Recent studies have suggested that several factors such as photobiomodulation (PBM) and vitamin D affect the proliferation and differentiation of HDPSCs. Therefore, the present study evaluated the effects of PBM and vitamin D on odontogenic differentiation of HDPSCs for dentin -like tissue formation. Methods: HDPSCs were collected, isolated, and characterized and then divided into six groups: group I, control; group II, vitamin D (10^-7 Mol); group III, irradiation at 1 J/cm² of 810 nm diode laser; group IV, irradiation at 1 J/cm² and culture with vitamin D; group V, irradiation at 2 J/cm², and group VI, irradiation at 2 J/cm² and culture with vitamin D, cell viability assay was measured through MTT. Alkaline phosphatase (ALP) enzyme activity and mRNA levels of vascular endothelial growth factor (VEGF), bone morphogenic protein-2 (BMP-2), and dentin sialophosphoprotein (DSPP) were also assessed. Results: PBM at 1 and 2 J/cm² combined with vitamin D significantly promoted HDPSCs proliferation through MTT assay and odontogenic differentiation through gene expression of VEGF, BMP-2, and DSPP levels (P < 0.0001). Conclusion: PBM at 2 J/cm² combined with vitamin D enhanced the HDPSCs proliferation and odontogenic differentiation and thus could be a novel strategy for dentin regeneration in dentistry.

LASER in periodontal treatment: is it an effective treatment or science fiction?

There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Stellate Ganglion Phototherapy Using Low-Level Laser: A Novel Rescue Therapy for Patients With Refractory Ventricular Arrhythmias

OBJECTIVES

This study investigates the effect of stellate ganglion (SG) phototherapy in healthy participants and assesses its efficacy in suppressing electrical storm (ES) refractory to antiarrhythmic drugs and catheter ablation.

BACKGROUND

Modulation of the autonomic nervous system has been shown to be an effective adjunctive therapy for ES.

METHODS

Ten-minute SG phototherapy was performed twice weekly for 4 weeks in 20 healthy volunteers. To evaluate the acute and chronic effects of SG phototherapy, heart rate variability and serum concentrations of adrenaline, noradrenaline, and dopamine were obtained before phototherapy, immediately after the first phototherapy session, after 8 sessions of phototherapy, and 3 months after the first phototherapy session. In addition, the efficacy of SG phototherapy was evaluated in 11 patients with ES refractory to medication, sedation, and catheter ablation.

RESULTS

In healthy participants, serum adrenaline concentration significantly decreased after phototherapy, whereas low-frequency power/high-frequency power significantly decreased during phototherapy. Moreover, the effect on heart rate variability did not last beyond 3 months. In the clinical pilot study, 7 patients had a suppression of ES after SG phototherapy; however, without maintenance therapy, 2 patients had a recurrence of ventricular arrhythmias. Furthermore, it did not control ES in 4 patients.

CONCLUSIONS

SG phototherapy reduced sympathetic activity and may be a safe and effective adjunctive therapy to control ES in some patients, but its long-term efficacy remains unknown. Chronic phototherapy might help reduce ES recurrence.

Effects of photobiomodulation on bone remodeling in an osteoblast-osteoclast co-culture system

The general bone anabolic effect of photobiomodulation (PBM) is largely accepted. As a result, PBM therapy is expected to be beneficial in the medical fields of dentistry and bone healing. However, most of the previous in vitro studies on PBM and bone metabolism were performed with single-cell cultures of osteoclast-lineage cells or osteoblast-lineage cells. In the present study, the bone-modulating effects of PBM were evaluated in an in vitro osteoblast/osteoclast co-culture system. Mouse bone marrow-derived macrophages (BMMs) and mouse calvarial pre-osteoblasts cells were purified and used as precursor cells for osteoclasts and osteoblasts, respectively. The PBM effects on single-cell culture of osteoclasts or osteoblasts as well as co-culture were examined by 1.2 J/cm² low-level Ga-Al-As laser (λ  = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1cm²; NDLux, Seoul, Korea) irradiation for 30 s at daily intervals throughout culture period. At the end of culture, the osteoclast differentiation and osteoblast differentiation were assessed by TRAP staining and ALP staining, respectively. The expressions of osteoclastogenic cytokines were evaluated by RT-PCR and Western blot analyses. Under the single-cell culture condition, PBM enhanced osteoblast differentiation but had minor effects on osteoclast differentiation. However, in the co-culture condition, its osteoblastogenic effect was maintained, and osteoclast differentiation was substantially reduced. Subsequent RT-PCR analyses and western blot results revealed marked reduction in receptor activator of NF-κB ligand (RANKL) expression and elevation in osteoprotegerin (OPG) expression by PBM in co-cultured cells. More importantly, these alterations in RANKL/OPG levels were not observed under the single-cell culture conditions. Our results highlight the different effects of PBM on bone cells based on culture conditions. Further, our findings suggest the indirect anti-osteoclastogenic effect of PBM, which is accompanied by a decrease in RANKL expression and an increase in OPG expression.

Effective Low-Level Laser Therapy Including Laser Acupuncture Treatment Conditions for Non-Specific Chronic Low Back Pain: Systematic Review and Meta-Analysis

Low-level laser therapy including laser acupuncture has been widely used for non-specific chronic low back pain in primary Korean medical clinics. However, there is no critically appraised data regarding which treatment conditions are most effective. A systematic review and meta-analysis was conducted to determine effective treatment conditions using 12 databases (PubMed, Ovid, CENTRAL, KoreaMed, KMBASE, KISS, NDSL, KISTI, OASIS, CNKI, CiNII, and J-STAGE). There were 1,019 studies retrieved and 13 studies included in this review. It was determined that when the power output was ≥ 50 mW, the beam size was increased to ≥ 1 cm2, the energy dose was increased to ≥ 4 J per point, the treatment interval was increased to ≥ 3 times a week, and the number of treatment sessions was increased to ≥ 10 treatments, these conditions appeared to increased treatment effectiveness.

Comparative evaluation of the efficacy of diode laser as an adjunct to modified Widman flap surgery for the treatment of chronic periodontitis: A randomized split-mouth clinical trial

BACKGROUND

Periodontitis is a chronic inflammatory disease that is mainly initiated by plaque biofilm which may require treatment using periodontal flap surgery. Recently, diode lasers have become popular in the field of periodontology owing to advantages such as antibacterial effect, promoting angiogenesis, and providing hemostasis. However, scientific data on application of diode laser in periodontal flap surgery and its benefits are limited. Hence, the aim of the study was to investigate the adjunctive effect of removal of remnant pocket epithelium by 980 nm diode laser and biostimulation in modified Widman flap (MWF) surgery for the treatment of chronic periodontitis.

MATERIALS AND METHODS

A total of 20 patients with generalized chronic periodontitis with pocket probing depth (PPD) ≥5mm post Phase I therapy were selected for this split-mouth study. MWF surgery was performed in Group 1, and in Group 2, MWF surgery with adjunctive diode laser de-epithelization and biostimulation was done. Clinical parameters including PPD, clinical attachment level, plaque index, and gingival index were recorded at baseline and 3 months following treatment, and postprocedural pain (Visual Analog Scale [VAS] score) was assessed 1-week posttreatment. In addition, colony-forming units/milliliter (CFU/ml) of anaerobic bacteria at baseline and 3 months were microbiologically examined.

RESULTS

MWF surgery along with diode laser led to a significant improvement in Group 2 compared to Group 1 in clinical parameters such as PPD, relative clinical attachment level, VAS score as well as microbial parameter CFU/ml after 3 months.

CONCLUSION

Diode laser as an adjunct to MWF in chronic periodontitis can provide enhanced clinical attachment gain with little postoperative discomfort.

Effect of photobiomodulation therapy on painful temporomandibular disorders

To evaluate the effect of photobiomodulation therapy (PBMT) on painful temporomandibular disorders (TMD) patients in a randomized, double-blinded, placebo-controlled manner. Participants were divided into a masseter myalgia group (n = 88) and a temporomandibular joint (TMJ) arthralgia group (n = 87) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Both groups randomly received PBMT or placebo treatment once a day for 7 consecutive days, one session. The PBMT was applied with a gallium-aluminum-arsenide (GaAlAs) laser (wavelength = 810 nm) at pre-determined points in the masseter muscle (6 J/cm², 3 regions, 60 s) or TMJ region (6 J/cm², 5 points, 30 s) according to their most painful site. Pain intensity was rated on a 0–10 numerical rating scale (NRS) and pressure pain thresholds (PPT) and mechanical sensitivity mapping were recorded before and after the treatment on day 1 and day 7. Jaw function was assessed by pain free jaw opening, maximum unassisted jaw opening, maximum assisted jaw opening, maximum protrusion and right and left excursion. Data were analyzed with a mixed model analysis of variance (ANOVA). Pain intensity in arthralgia patients decreased over time (P < 0.001) for both types of interventions, however, PBMT caused greater reduction in pain scores than placebo (P = 0.014). For myalgia patients, pain intensity decreased over time (P < 0.001) but without difference between interventions (P = 0.074). PPTs increased in both myalgia (P < 0.001) and TMJ arthralgia patients over time (P < 0.001) but without difference between interventions (P ≥ 0.614). Overall, PBMT was associated with marginally better improvements in range of motion compared to placebo in both myalgia and arthralgia patients. Pain intensity, sensory function and jaw movements improve after both PBMT and placebo treatments in myalgia and arthralgia patients indicating a substantial non-specific effect of PBMT.

Evaluation of Adjunctive Photobiomodulation (PBMT) for COVID-19 Pneumonia via Clinical Status and Pulmonary Severity Indices in a Preliminary Trial

PURPOSE

Evidence-based and effective treatments for COVID-19 are limited, and a new wave of infections and deaths calls for novel, easily implemented treatment strategies. Photobiomodulation therapy (PBMT) is a well-known adjunctive treatment for pain management, wound healing, lymphedema, and cellulitis. PBMT uses light to start a cascade of photochemical reactions that lead to local and systemic anti-inflammatory effects at multiple levels and that stimulate healing. Numerous empirical studies of PBMT for patients with pulmonary disease such as pneumonia, COPD and asthma suggest that PBMT is a safe and effective adjunctive treatment. Recent systematic reviews suggest that PBMT may be applied to target lung tissue in COVID-19 patients. In this preliminary study, we evaluated the effect of adjunctive PBMT on COVID-19 pneumonia and patient clinical status.

PATIENTS AND METHODS

We present a small-scale clinical trial with 10 patients randomized to standard medical care or standard medical care plus adjunctive PBMT. The PBMT group received four daily sessions of near-infrared light treatment targeting the lung tissue via a Multiwave Locked System (MLS) laser. Patient outcomes were measured via blood work, chest x-rays, pulse oximetry and validated scoring tools for pneumonia.

RESULTS

PBMT patients showed improvement on pulmonary indices such as SMART-COP, BCRSS, RALE, and CAP (Community-Acquired Pneumonia questionnaire). PBMT-treated patients showed rapid recovery, did not require ICU admission or mechanical ventilation, and reported no long-term sequelae at 5 months after treatment. In the control group, 60% of patients were admitted to the ICU for mechanical ventilation. The control group had an overall mortality of 40%. At a 5-month follow-up, 40% of the control group experienced long-term sequelae.

CONCLUSION

PBMT is a safe and effective potential treatment for COVID-19 pneumonia and improves clinical status in COVID-19 pneumonia.

Therapeutic alternatives in the management of osteoradionecrosis of the jaws. Systematic review

Background

to systematically review the literature, comparing the healing of osteoradionecrosis (ORN) among the therapeutic alternatives: surgical, pharmacological and combined.

Material and Methods

The review was organized according to the PRISMA protocol with regards to the following PICO question: patients with ORN of the jaws (P=Patient); all interventions reported (I = intervention); between all therapies (C=Comparison); healing of lesions (O=outcome).

Results

Surgical treatment was the most common choice (46.3%) followed by pharmacological treatment, exclusively (25.9%) or combined (26.9%). Treatment exclusively by surgical intervention seems to be most effective option, with 51.2% of the lesions healed, OR for healing of 5.7 (CI95% 1.9-16.9, p=0.002). Only 1 case (0.9%) corresponded to low level laser therapy.

Conclusions

It seems clear that early intervention with conservative surgical combined with pharmacological methods improves the prognosis of ORN.

Key words:Osteoradionecrosis, radiotherapy bone necrosis, hyperbaric oxygen, pentoxifylline, teriparatide, low level laser therapy.

Complementarity of Photo-Biomodulation, Surgical Treatment, and Antibiotherapy for Medication-Related Osteonecrosis of the Jaws (MRONJ)

Background and Objectives: Antiresorptive or anti-angiogenic agents may induce medication-related osteonecrosis of the jaws (MRONJ), which represents a challenge for clinicians. The aim of this study is to design and apply a composed and stage-approach therapy combining antibiotherapy, surgical treatment, and photo-biomodulation (PBM) for the prevention or treatment of MRONJ lesions. Materials and Methods: The proposed treatment protocol was carried out in the Department of Oral & Maxillofacial Surgery of the “Victor Babes” University of Medicine and Farmacy of Timisoara, in 2018–2020. A total of 241 patients who were previously exposed to antiresorptive or anti-angiogenic therapy, as well as patients already diagnosed with MRONJ at different stages of the disease were treated. A preventive protocol was applied for patients in an “at risk” stage. Patients in more advanced stages received a complex treatment. Results: The healing proved to be complete, with spontaneous bone coverage in all the n = 84 cases placed in an “at risk” stage. For the n = 49 patients belonging to stage 0, pain reductions and decreases of mucosal inflammations were also obtained in all cases. For the n = 108 patients proposed for surgery (i.e., in stages 1, 2, or 3 of MRONJ), a total healing rate of 91.66% was obtained after the first surgery, while considering the downscaling to stage 1 as a treatment “success”, only one “failure” was reported. This brings the overall “success” rate to 96.68% for a complete healing, and to 99.59% when downscaling to stage 1 is included in the healing rate. Conclusions: Therefore, the clinical outcome of the present study indicates that patients with MRONJ in almost all stages of the disease can benefit from such a proposed association of methods, with superior clinical results compared to classical therapies.

Photobiomodulation enhances the Th1 immune response of human monocytes

This study aims to evaluate the effects of photobiomodulation (PBM) on human monocytes, assessing the oxidative burst and ultimate fungicidal potential of these cells, as well as the gene expression at the mRNA level of CD68, CD80, CD163, CD204, IL-6, TNF-α and IL-10 in derived macrophages. Primary cultures of human monocytes were irradiated with an InGaAlP (660 nm)/GaAlAs (780 nm) diode laser (parameters: 40 mW, 0.04 cm², 1 W/cm²; doses: 200, 400 and 600 J/cm²). Cells were submitted to the chemiluminescence assay, and a microbicidal activity assay against Candida albicans was performed. Reactive oxygen species (ROS) and nitric oxide (NO) production were measured, and cell viability was assessed by the exclusion method using 0.2% Trypan blue reagent. Irradiated monocytes were cultured for 72 h towards differentiation into macrophages. Total RNA was extracted, submitted to reverse transcription and real-time PCR. The results were analysed by ANOVA and the Tukey test (α = 0.05). Irradiated monocytes revealed a significant increase in their intracellular and extracellular ROS (P < 0.001). The 660 nm wavelength and 400 J/cm² dose were the most relevant parameters (P < 0.001). The fungicidal capacity of the monocytes was shown to be greatly increased after PBM (P < 0.001). PBM increased the expression of TNF-α (P = 0.0302) and the production of NO (P < 0.05) and did not impair monocyte viability. PBM induces a pro-inflammatory Th1-driven response in monocytes and macrophages.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to open flap debridement in patients with aggressive periodontitis

AIM

The aim of the present clinical trial was to evaluate the clinical efficacy of photodynamic therapy (PDT) as an adjunct to open flap debridement (OFD) in the treatment of generalized aggressive periodontitis (GAP).

MATERIALS AND METHODS

The subjects recruited for the study were divided into two groups: 'control group' received treatment through OFD, whereas the test participants were treated with OFD and adjunctive PDT. The clinical periodontal parameters were plaque index (PI), full mouth probing depth (FMPD) and full mouth relative attachment loss (FMRA). The microbial levels of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannarella forsythia (Tf) were analyzed. All parameters were assessed at baseline and 3 months.

STATISTICAL ANALYSIS

The observed values for all the parameters were reported in mean and standard deviation (mean ± SD). In order to analyse the mean values and inter-group comparisons, the Mann-Whitney U test was employed. The p-value was set at <0.05 to establish a significant difference among the reported values.

RESULTS

A statistically significant improvement for BOP was observed in PDT group in comparison to the control group at 3 months only (p < 0.05). A significant reduction in the microbiological levels for Aa, Pg and Tf in both the study groups was observed. However, no significant differences in microbial levels were observed at any time point when the control and test groups were compared to each other.

CONCLUSION

PDT in conjuction with OFD plays a significant role in reducing the microbial load and improving the clinical periodontal parameters in patients with GAP. Moreover, it is regarded as a safe treatment regimen as no side effects have been reported regarding its use in GAP.

Photobiomodulation of the Visual System and Human Health

Humans express an expansive and detailed response to wavelength differences within the electromagnetic (EM) spectrum. This is most clearly manifest, and most studied, with respect to a relatively small range of electromagnetic radiation that includes the visible wavelengths with abutting ultraviolet and infrared, and mostly with respect to the visual system. Many aspects of our biology, however, respond to wavelength differences over a wide range of the EM spectrum. Further, humans are now exposed to a variety of modern lighting situations that has, effectively, increased our exposure to wavelengths that were once likely minimal (e.g., “blue” light from devices at night). This paper reviews some of those biological effects with a focus on visual function and to a lesser extent, other body systems.

Effect of Multiradiance Low-Level Laser Therapy and Topical Silver Sulfadiazine on Healing Characteristics of Dermal Wounds in Marine Toads (Rhinella marina)

Current recommendations for wound management in amphibians are based primarily on clinical experience and on extrapolation from other taxa, whereas controlled clinical studies are lacking. Low-level laser therapy, also termed photobiomodulation, has gained popularity in veterinary medicine and may represent a valuable adjunct therapy for wound care in amphibians, though dosing and safety evaluations have not been previously reported. Silver sulfadiazine (SSD), a topical antimicrobial, is commonly utilized in amphibian medicine but little is known about its effects on wound healing in this class of animals. This pilot study evaluated the effects of repeated treatments of low-level laser therapy or topical SSD on second-intention healing characteristics of surgically induced full-thickness dermal wounds in 33 adult wild-caught marine toads. Toads were anesthetized, and a 6 mm cutaneous biopsy was performed over the right dorsum. They were then randomly assigned to one of three groups: laser therapy (LT) at 5 Hz (905 nm wavelength on a super pulsed sequence), topical SSD (SD), or control sham treatment (CT). Treatments were administered at 24 hrs after biopsy and then every 72 hrs thereafter, concurrent with a visual assessment of the wound. Toads were euthanized at one of five timepoints (day 4, 7, 13, 19, or 28) to permit scoring of histologic criteria, including lymphocytic inflammation, granulomatous inflammation, heterophilic inflammation, granulation tissue, fibrosis, and reepithelialization. Visual assessments and histologic scoring did not identify a benefit of laser therapy or SSD as compared to controls. Laser therapy and SSD, at the doses and dosing schedule utilized in this pilot study, appear to be safe and well-tolerated treatments in marine toads, but may not be warranted for uncomplicated skin wounds in this species.

Physical therapy for tendinopathy: An umbrella review of systematic reviews and meta-analyses

OBJECTIVE

To summarize evidence in the last decade regarding the efficacy of physical therapy interventions to treat tendinopathy, as a single disease entity, as determined in systematic reviews (SRs) and/or meta-analyses (MAs).

METHODS

Electronic search of PubMed, PEDro, and Scopus database was performed from year 2010 to January 2020. The methodological quality of the identified studies was assessed using the AMSTAR 2 tool. Studies scoring 9 points or higher were further analyzed using GRADE principles.

RESULTS

40 SRs and/or MAs were included in qualitative synthesis, whereas only 5 MAs were included in quantitative synthesis. Low-level laser therapy (LLLT) intervention showed a pooled improvement in pain reduction of 1.53 cm; 95% CI, [1.14, 1.91] (I² = 1.9%, p = 0.361) on visual analogue scale, and grip strength of 9.59 kg; 95% CI, [5.90, 13.27].

CONCLUSIONS

Moderate-quality evidence may support these following interventions: LLLT revealed a statistically and potentially clinically significant improvement in pain and function on the short-term. Extracorporeal shockwave therapy showed a statistically significant enhancement in pain and function at all follow-up durations; however, its clinical significance was undetermined. Eccentric exercise was supported by qualitative evidence only. Caution is advised when interpreting results due to possible pathological differences in tendinopathy at each region.

Low level laser therapy as a modality to attenuate cytokine storm at multiple levels, enhance recovery, and reduce the use of ventilators in COVID-19

The global pandemic COVID-19 is a contagious disease and its mortality rates ranging from 1% to 5% are likely due to acute respiratory distress syndrome (ARDS), and cytokine storm. A significant proportion of patients who require intubation succumb to the disease, despite the availability of ventilators and the best treatment practices. Researchers worldwide are in search of anti-inflammatory medicines in the hope of finding a cure for COVID-19. Low-level laser therapy (LLLT) has strong, anti-inflammatory effects confirmed by meta-analyses, and it may be therapeutic to ARDS. LLLT has been used for pain management, wound healing, and other health conditions by physicians, physiotherapists, and nurses worldwide for decades. In addition, it has been used in veterinary medicine for respiratory tract disease such as pneumonia. Laser light with low-power intensity is applied to the surface of the skin to produce local and systemic effects. Based on the clinical experience, peer-reviewed studies, and solid laboratory data in experimental animal models, LLLT attenuates cytokine storm at multiple levels and reduces the major inflammatory metabolites. LLLT is a safe, effective, low-cost modality without any side-effects that may be combined with conventional treatment of ARDS. We summarize the effects of LLLT on pulmonary inflammation and we provide a protocol for augmenting medical treatment in COVID-19 patients. LLLT combined with conventional medical therapy has the potential to prevent the progression of COVID-19, minimize the length of time needed on a ventilator, enhance the healing process, and shorten recovery time.

Does Photobiomodulation Therapy Enhance Maximal Muscle Strength and Muscle Recovery?

Photobiomodulation has been shown to improve tissue and cell functions. We evaluated the influence of photobiomodulation, using a B-Cure laser, on: 1) maximal performance, and 2) muscle recovery after resistance exercise. Two separate crossover randomized double-blinded placebo-controlled trials were conducted. Sixty healthy physical education students (28 men, 32 women), aged 20-35, were recruited (30 participants for each trial). Participants performed two interventions for each experiment, with real lasers (GaAlAs, 808 nm) on three quadricep locations in parallel (overall treatment energy of ~150J) or sham (placebo) treatment. In the first experiment muscle total work (TW) and peak torque (PT) were measured by an isokinetic dynamometer in five repetitions of knee extension, and in the second experiment muscle recovery was measured after the induction of muscle fatigue by evaluating TW and PT in five repetitions of knee extension. There were no differences between treatments (real or sham) regarding the TW (F(1,28) = 1.09, p = .31), or PT (F(1,29) = .056, p = .814). In addition, there was no effect of photobiomodulation on muscle recovery as measured by the TW (F(1,27) = .16, p = .69) or PT (F(1,29) = .056, p = .814). Applying photobiomodulation for 10 min immediately before exercise did not improve muscle function or muscle recovery after fatigue.

Photobiomodulation for mucosal repair in patients submitted to dental extraction after head and neck radiation therapy: a double-blind randomized pilot study

OBJECTIVE

The aim of this study was to evaluate the efficacy of photobiomodulation therapy (PBMT) on the mucosal healing of patients submitted to simple dental extractions after head and neck radiation therapy (HNRT).

METHODS

Forty surgical procedures were randomly assigned into two groups: G1: dental extraction + PBMT (n = 19) and G2: dental extraction + sham-PBMT (n = 21). All patients received antibiotic therapy and the surgical alveolotomy to promote primary closure of the surgical site. Group 1 was submitted to PMBT according to the following parameters: 808 nm, 40 mW, 100 J/cm², 70 s, 2.8 J/point, 14 J/session, and area of 0.028cm². The primary outcome was complete mucosal lining at 14 days, and the secondary outcomes were the presence of infection, postoperative pain, and analgesics intake at 7 days. The patients were evaluated every 7 days until 28 days.

RESULTS

Alveolar mucosal lining was faster in G1, and at 14 postoperative days, 94.7% patients evolved with complete alveolar mucosal lining compared to no patient from G2 (p < 0.001). Patients from G1 reported postoperative pain less frequently (G1 = 4, 21.1% × G2 = 14, 66.7%, p = 0.005), and also reported lower intake of analgesic pills at D7 (21.1% × 66.7%, p = 0.005%). PBMT had a significant positive impact on both postoperative pain (NNT = 2.192, CI95% = 1.372-5.445) and mucosal healing (NNT = 1.056, CI95% = 0.954-1.181).

CONCLUSIONS

This preliminary study strongly supports the use of PMBT to promote surgical alveolar mucosal lining in a shorter time and with less postoperative pain.

The effect of low-level laser therapy as an adjunct to periodontal surgery in the management of postoperative pain and wound healing: a systematic review and meta-analysis

The meta-analysis and systematic review aimed to evaluate the effect of low-level laser therapy (LLLT) as an adjunct to periodontal surgery in the management of postoperative pain and wound healing. An electronic search in 4 databases (PubMed, Embase, Cochrane, and OpenGrey) was conducted for randomized clinical trials reporting the effectiveness of LLLT used as an adjunct to periodontal surgery to alleviate pain and accelerate wound healing compared with surgery alone. Finally, 13 studies were eligible and included. The results showed a significant difference of pain relief between groups at day 3 post-surgery, whereas no difference was found at day 7. Moreover, a significant reduction was observed in the mean analgesic intake during the first week in the LLLT group. On day 14, the adjunctive use of LLLT showed significantly faster re-epithelialization and better wound healing in palatal donor sites following free gingival graft procedures. Based on the results, LLLT used as an adjunct to periodontal surgery positively influenced postsurgical pain control. Low power (≤ 500 mW) combined with energy density ≥ 5 J/cm² might be more appropriate for postoperative pain relief. Moreover, adjunctive LLLT to free gingival grafts could significantly accelerate wound healing of palate sites at early healing phase. Multicenter studies using different LLL parameters without postsurgical analgesics are needed to determine optimal laser settings.

Effects of Low-Level Er:YAG Laser Irradiation on Proliferation and Calcification of Primary Osteoblast-Like Cells Isolated From Rat Calvaria

Several reports have shown that the photo-bio-modulation of cells by various lasers has favorable biological effects. However, the effects of low-level Er:YAG laser irradiation on osteoblasts remain unclear. The purpose of this study was to evaluate the effects of low-level Er:YAG laser irradiation on proliferation and osteogenic differentiation of primary osteoblast-like cells isolated from the calvariae of 3-5-day-old Wistar rats. Cells were irradiated by Er:YAG laser at energy fluences of 2.2, 3.3, and 4.3 J/cm2, respectively. After irradiation, cell surface temperatures were measured and cell proliferation was evaluated by flow cytometry and CCK-8. Calcification was evaluated by measuring areas of Alizarin red S staining after 7, 14, and 21 days culture in osteoinductive medium. Gene expression in non-irradiated and laser-irradiated cells was evaluated by qPCR at 3, 6, and 12 h, as well as 1, 3, 7, and 14 days after irradiation. Microarray analysis was performed to comprehensively evaluate the gene expression of non-irradiated and irradiated cells at 3.3 J/cm2 at 6 h after irradiation. No pronounced increase of cell surface temperature was induced by irradiation. Irradiation did not affect osteoblast-like cell proliferation. Osteoblast-like cell calcification was significantly increased 7 days after Er:YAG laser irradiation at 3.3 J/cm2. Bglap expression was significantly increased in cells irradiated at 3.3 J/cm2 6 h post-irradiation. Microarray analysis showed that irradiation at 3.3 J/cm2 caused an upregulation of inflammation-related genes and downregulation of Wisp2. Gene set enrichment analysis also clarified enrichment of inflammation-related and Notch signaling gene sets. In conclusion, low-level Er:YAG laser irradiation at 3.3 J/cm2 enhanced calcification of primary osteoblast-like cells via enhanced Bglap expression and enriched Notch signaling.

Medication association and immunomodulation: An approach in fungal diseases and in particular in the treatment of paracoccidioidomycosis

Fungal infections have been increasing in recent decades, mainly affecting immunocompromised individuals, although certain mycoses, such as paracoccidioidomycosis (PCM), infect immunologically competent individuals. The major problems observed regarding fungal diseases are inadequate diagnosis, prolonged treatment time, the reduced number of drugs available for treatment, in addition to the fact that there are no vaccines for clinical use. Drug combination in order to immunomodulate the immune response is a new strategy used for the treatment of mycoses, since it is difficult to develop new antifungal drugs. The aim of this study is to present and analyze strategies recently suggested for the treatment of fungi of medical interest, in particular for PCM, such as the utilization of combinations of protein fractions or dead microorganisms, as vaccinal antigens, and cellular immunotherapy. We will also propose new therapeutic alternatives, such as lipids, vitamins, synthetic or natural products as well as the use of low intensity LASER therapy (LLLT) to modulate the immune response of the host, enhancing the efficiency of the existing treatments of mycoses of medical interest and in particular of PCM.

Effect of 632 nm He-Ne Laser on Gram-Positive Bacteria in Deep Partial Thickness Pediatric Burn: A Prospective Double-Blind Randomized Controlled Trial

Background. Burns are one of the most common injuries in pediatric population, gram-positive bacteria is the main pathogens responsible for wound infection that is the leading cause of morbidity and sometimes mortality in growing children with burn. Low level laser is a new treatment option that is increasingly used in the field of wound healing. Aim. To investigate the effect of He-Ne laser on gram-positive bacteria and healing time of deep second-degree pediatric burn. Methods. Thirty children of both genders aged from 2 to 9 years old with 2nd degree upper limb burn infected with gram-positive bacteria participated in this study. They were randomly assigned into two equal groups; either the control group (group A) received systematic antibiotic and 10 minutes’ placebo laser light, or the laser group (group B) received 632 nm laser light, 6 J/cm2 scanning technique for 10 minutes. All patients received regular wound care (dressing). The study protocol was once a day, 3 times / week for one month. Pre and post-treatment evaluation of wound culture and the healing time was recorded for both groups. Results. Wound culture of all children in both groups were negative after two weeks of the study and wound healing time was significantly shorter in the laser group (14.6±5.7 days) than the control group (27±7.3 days). Conclusion. He-Ne laser is an effective option of treatment for 2nd-degree pediatric burn as it has a bactericidal effect on gram-positive bacteria and accelerates wound healing process significantly.

Fluorescent Light Energy (FLE) Acts on Mitochondrial Physiology Improving Wound Healing

Fluorescent light energy (FLE) has been used to treat various injured tissues in a non-pharmacological and non-thermal fashion. It was applied to stimulate cell proliferation, accelerate healing in chronic and acute wounds, and reduce pain and inflammation. FLE has been shown to reduce pro-inflammatory cytokines while promoting an environment conducive to healing. A possible mechanism of action of FLE is linked to regulation of mitochondrial homeostasis. This work aims to investigate the effect of FLE on mitochondrial homeostasis in an in vitro model of inflammation. Confocal microscopy and gene expression profiling were performed on cultures of inflamed human dermal fibroblasts treated with either direct light from a multi-LED lamp, or FLE from either an amorphous gel or sheet hydrogel matrix. Assessment using confocal microscopy revealed mitochondrial fragmentation in inflamed cells, likely due to exposure to inflammatory cytokines, however, mitochondrial networks were restored to normal 24-h after treatment with FLE. Moreover, gene expression analysis found that treatment with FLE resulted in upregulation of uncoupling protein 1 (UCP1) and carnitine palmitoyltransferase 1B (CPT1B) genes, which encode proteins favoring mitochondrial ATP production through oxidative phosphorylation and lipid β-oxidation, respectively. These observations demonstrate a beneficial effect of FLE on mitochondrial homeostasis in inflamed cells.

Opposite effects of low intensity light of different wavelengths on the planarian regeneration rate

Planarian freshwater flatworms have the unique ability to regenerate due to stem cell activity. The process of regeneration is extremely sensitive to various factors, including light radiation. Here, the effect of low-intensity LED light of different wavelengths on regeneration, stem cell proliferation and gene expression associated with these processes was studied. LED matrices with different wavelengths (red (λ_max = 635 nm), green (λ_max = 520 nm) and blue (λ_max = 463 nm), as well as LED laser diodes (red (λ_max = 638.5 nm), green (λ_max = 533 nm) and blue (λ_max = 420 nm), were used in the experiments. Computer-assisted morphometry, whole-mount immunocytochemical study and RT-PCR were used to analyze the biological effects of LED light exposure on the planarian regeneration in vivo. It was found that a one-time exposure of regenerating planarians with low-intensity red light diodes stimulated head blastema growth in a dose-dependent manner (up to 40%). The green light exposure of planarians resulted in the opposite effect, showing a reduced head blastema growth rate by up to 21%. The blue light exposure did not lead to any changes in the rate of head blastema growth. The maximum effects of light exposure were observed at a dose of 175.2 mJ/cm². No significant differences were revealed in the dynamics of neoblasts' (planarian stem cells) proliferation under red and green light exposure. However, the RT-PCR gene expression analysis of 46 wound-induced genes revealed their up-regulation upon red LED light exposure, and down-regulation upon green light exposure. Thus, we have demonstrated that the planarian regeneration process is rather sensitive to the effects of low-intensity light radiation of certain wavelengths, the biological activity of red and green light being dictated by the different expression of the genes regulating transcriptional activity.

An Open-Label Study of Low-Level Laser Therapy Followed by Autologous Fibroblast Transplantation for Healing Grade 3 Burn Wounds in Diabetic Patients

Introduction: Low-level laser therapy (LLLT) has been used as an effective therapeutic modality since the mid-1960s. Although there have been several clinical studies using LLLT in wound healing, especially diabetic, pressure and venous ulcers, there are few reports of using this technique in burn ulcers. Autologous fibroblast transplantation is a novel treatment for patients with burns or venous ulcers. In this study for the first time, we used LLLT along with autologous fibroblast skin transplantation to treat grade 3 burn ulcers in diabetic patients. This case series describes the successful management of grade 3 burn ulcers in 10 diabetic patients using autologous fibroblast transplantation along with LLLT. Methods: After the approval of the Tehran University Ethics Committee (IR.TUMS.REC.1394.1683) and the Iran Registry of Clinical Trials (IRCT2016050226069N3), 10 diabetic patients with 10 grade 3 burn ulcers, who were a candidate for skin graft surgery, entered the study. Donor skin was biopsied using a 3 mm punch. Fibroblasts were extracted and cultured in vitro in the GMP Technique laboratory. The patients were treated using LLLT in 3-4 weeks during the time that fibroblast cultures became ready to use. Laser irradiation was done using red light, 650 nm, 150 mW, 1 J/cm² for the bed of the ulcer and infra-red light 808 nm, 200 mW, 6 J/cm² for the margins every other day for 10 sessions. Results: The mean wound size before treatment was 16.28 cm² . All patients' burn wounds healed completely after 10-12 weeks. Conclusion: We conclude that this method can be used as an effective method for treating large wounds, especially in complicated patients including the diabetics.