Low intensity laser therapy: still not an established clinical tool

The impact of low-level laser therapy (photobiomodulation) on the complications associated with conventional dental treatments and oral disorders: A literature review

Oral health-related quality of life (OHRQoL) refers to how oral conditions impact an individual's social interactions and positive perception of their dental and facial appearance. OHRQoL is a crucial patient-reported outcome in dentistry and typically includes four key dimensions: Oral Function, orofacial pain, orofacial appearance, and Psychosocial impact. The Oral Health Impact Profile (OHIP) is a widely used tool for evaluating OHRQoL due to its strong psychometric properties. It focuses on how individuals perceive the repercussions of oral health issues. Complications arising from oral disorders and dental procedures can significantly disrupt a patient's daily routine, affecting aspects such as diet, sleep, physical activities, and work immediately following the intervention, thereby impacting their overall OHRQoL. Low-level laser therapy (LLLT), also known as "photobiomodulation," has emerged as a promising adjunctive treatment option to reduce inflammation, expedite the healing process, and enhance patients' OHRQoL. LLLT influences various cellular functions, including adenosine triphosphate production, protein and prostaglandin synthesis, neurotransmitter release, cellular growth, differentiation, and phagocytosis. Considering the significance of how oral health issues and associated treatment complications affect patients' OHRQoL, this study aimed to review patient-centered outcome measures in the context of LLLT to evaluate its impact on the complications associated with conventional dental treatments and oral disorders and patients' OHRQoL.

Muscle Rehabilitation Techniques and Prevention of Injury

Rehabilitation following muscle injury is critical in restoring the equine athlete to full function. Rehabilitation protocols should be tailored to each patient's global functional assessment, taking into account sports-specific demands, goals for return-to-performance, and overall prognosis. Rehabilitation protocols are often designed to modulate pain, enhance repair, improve proprioception, increase flexibility, restore muscle strength, joint range-of-motion, and neuromotor control. This article will review mechanisms of muscle injury, various physical modalities commonly employed in the rehabilitation period following muscle injury, and injury prevention.

A Randomized Controlled Trial Evaluating the Effect of Local Application of Sodium Alendronate Gel and Low-Level Laser Therapy (LLLT) On Peri-Implant Tissue Healing in Wistar Rats

Objective

To evaluate the effect of local application of Sodium Alendronate incorporated in Carbapol gel together with LLLT on peri-implant tissue healing in Wistar rat femurs.

Methods

Twenty-four male Wistar rats were randomly divided into 4 groups: Group 1 (the control group), Group 2 (the Sodium Alendronate group), Group 3 (the Sodium Alendronate and LLLT group), and Group 4 (the LLLT group). Mini implants were placed in right and left femur bones in all the four groups. Implants of groups 2 and 3 were coated in 1mg Carbapol gel incorporated with 1 mg Sodium alendronate. Groups 3 and 4 were exposed to LLLT (CO 2 laser, wavelength 830nm; 2.1J/cm 2) on 1 st, 7 th, 14 th and 21 st day. Animals were sacrificed on the 28th day, following which the femurs were dissected out and stored in 10% buffered formaldehyde for histopathological analysis.

Results

Groups 3 and 4 showed bony union and formation of reorganized spongiosa whereas Groups 1 and 2 showed fibrous union. The bone marrow from Group 3 had an adult-type fatty marrow, while that from Group 2 and 4 was occupied by red blood cells. Group 1 showed initial stages of bone healing in which the defect occupied more than half of the bone marrow.

Conclusion

LLLT given using CO 2 laser therapy, together with a one-time application of Sodium Alendronate in Carbapol gel at the time of implant placement optimally enhances healing of peri-implant tissues.

Effect of photobiomodulation treatment on pain control in patients with temporomandibular dysfunction disorder: systematic review

OBJECTIVE

To critically evaluate the literature and answer the question, "How effective is photobiomodulation treatment on pain control in patients with TMJ disorder?".

METHODS

PRISMA, PubMed, Web of Science, Scopus, and Embase databases were used for the personalized search strategy. For risk of bias, Rob 2.0 for randomized clinical trials and ROBINS-I for non-randomized clinical trials were used.

RESULTS

Eighty-four articles were found and, after removing duplicates, seventy one studies were included for titles and abstracts. For a full reading, 30 articles were selected and, according to the eligibility criteria, 24 remained for qualitative analysis. The studies showed a low risk of bias. Due to the heterogeneity of the studies, it was not possible to perform a meta-analysis.

CONCLUSION

Photobiomodulation is an effective adjunct for the treatment of temporomandibular disorders, being a less invasive approach, safe, low-cost, and without side effects.

Enhanced forward scattering of a cell in line optical tweezers with an astigmatic beam

The line optical tweezers (LOT) has been proven to be an alternative technique to manipulating the biological cells because of the bigger potential compared with traditional optical tweezers with a highly focused spot. We deduce the 4 × 4 optical matrix of the astigmatic LOT to investigate the optical characteristics related to the systematic parameters. The comparison of the initial and scattered electric fields by the cell under the astigmatic and stigmatic LOT is implemented to illustrate that the forward scattered light from the astigmatic LOT is much stronger than that from the stigmatic LOT, so as to the cell deformations. It is demonstrated that the astigmatic LOT could provide a more efficient way to deform the cell not only in the focal plane, but also along the optical axis to screen large biomaterials in biomechanics.

Effect of high-intensity laser therapy versus shockwave therapy on selected outcome measures in osteoporotic long-term hemiparetic patients: a randomized control trial

BACKGROUND

This study aimed to compare the effects of high-intensity laser therapy (HILT) and extracorporeal shock wave therapy (ESWT) in treating consequences of osteoporosis in hemiparetic patients.

METHODS

A randomized controlled trial was conducted on hemiplegic patients with osteoporosis. They were randomly classified into three equal groups (n = 40 in each group). The control group received medication and traditional physiotherapy programs for stroke patients. The high-intensity laser (HIL) group received the same intervention as the control group in addition to high-intensity laser therapy. The shock wave (SW) group received the same intervention as the control group in addition to shock wave therapy. The three groups received an intervention that lasted 3 sessions/week for 12 weeks). All groups were assessed before and after therapy for the degree of pain, fall risk, and quality of life.

RESULTS

A statistically significant difference (p < 0.05) was found concerning VAS, which had a significant difference in favor of HILT and ESWT groups compared to the control group; however, no significant difference was determined between HIL and SW groups. Regarding the overall stability index, SFBBS, and QUALEFFO-41, there was a significant difference in favor of HIL and SW groups compared to the control group, and a significant difference was found in HIL when compared to SW.

CONCLUSION

The current study indicates that the combined traditional physical therapy and HILT and ESWT have clinical significance in improving osteoporotic long-term hemiparetic patients with more favor to HILT.

TRIAL REGISTRATION

The study was registered as a clinical trial at ClinicalTrial.gov ID (NCT05616611).

Effects of High-Intensity Laser Therapy (HILT) on Skin Surface Temperature and Vein Diameter in Healthy Racehorses with Clipped and Non-Clipped Coat

The aim of this study was to investigate the differences in the effects of high-intensity laser therapy (HILT) on skin surface temperature and vein diameter in the carpal joint region in racehorses with clipped and non-clipped treatment areas. The study included 20 Thoroughbreds split into two equal groups: clipped coat and non-clipped coat. Horses underwent thermographic examination to detect changes in skin surface temperature at the medial surface of the carpal joint, followed by ultrasonographic examination to assess changes in the diameter of the medial palmar vein before and after HILT. The increase in skin surface temperature after HILT was significantly lower in the group with clipped coat than in the non-clipped group. The group with clipped coat showed a greater increase in vessel diameter. There was a significantly weak negative correlation between the changes in average skin surface temperature and vein diameter in both groups. In conclusion, an efficient photothermal effect can be achieved in skin with a non-clipped coat and clipping the treatment area increases photobiostimulation of the tissue, while reducing the photothermal effect. Further research is needed to specify the parameters for the treatment of skin with clipped and non-clipped coat in order to perform effective laser therapy.

Tissue Bioengineering with Fibrin Scaffolds and Deproteinized Bone Matrix Associated or Not with the Transoperative Laser Photobiomodulation Protocol

Extending the range of use of the heterologous fibrin biopolymer, this pre-clinical study showed a new proportionality of its components directed to the formation of scaffold with a lower density of the resulting mesh to facilitate the infiltration of bone cells, and combined with therapy by laser photobiomodulation, in order to accelerate the repair process and decrease the morphofunctional recovery time. Thus, a transoperative protocol of laser photobiomodulation (L) was evaluated in critical bone defects filled with deproteinized bovine bone particles (P) associated with heterologous fibrin biopolymer (HF). The groups were: BCL (blood clot + laser); HF; HFL; PHF (P+HF); PHFL (P+HF+L). Microtomographically, bone volume (BV) at 14 days, was higher in the PHF and PHFL groups (10.45 ± 3.31 mm3 and 9.94 ± 1.51 mm3), significantly increasing in the BCL, HFL and PHFL groups. Histologically, in all experimental groups, the defects were not reestablished either in the external cortical bone or in the epidural, occurring only in partial bone repair. At 42 days, the bone area (BA) increased in all groups, being significantly higher in the laser-treated groups. The quantification of bone collagen fibers showed that the percentage of collagen fibers in the bone tissue was similar between the groups for each experimental period, but significantly higher at 42 days (35.71 ± 6.89%) compared to 14 days (18.94 ± 6.86%). It can be concluded that the results of the present study denote potential effects of laser radiation capable of inducing functional bone regeneration, through the synergistic combination of biomaterials and the new ratio of heterologous fibrin biopolymer components (1:1:1) was able to make the resulting fibrin mesh less dense and susceptible to cellular permeability. Thus, the best fibrinogen concentration should be evaluated to find the ideal heterologous fibrin scaffold.

Use of Photobiomodulation Combined with Fibrin Sealant and Bone Substitute Improving the Bone Repair of Critical Defects

In this preclinical protocol, an adjunct method is used in an attempt to overcome the limitations of conventional therapeutic approaches applied to bone repair of large bone defects filled with scaffolds. Thus, we evaluate the effects of photobiomodulation therapy (PBMT) on the bone repair process on defects filled with demineralized bovine bone (B) and fibrin sealant (T). The groups were BC (blood clot), BT (B + T), BCP (BC + PBMT), and BTP (B + T + PBMT). Microtomographically, BC and BCP presented a hypodense cavity with hyperdense regions adjacent to the border of the wound, with a slight increase at 42 days. BT and BTP presented discrete hyperdensing areas at the border and around the B particles. Quantitatively, BCP and BTP (16.96 ± 4.38; 17.37 ± 4.38) showed higher mean bone density volume in relation to BC and BT (14.42 ± 3.66; 13.44 ± 3.88). Histologically, BC and BCP presented deposition of immature bone at the periphery and at 42 days new bone tissue became lamellar with organized total collagen fibers. BT and BTP showed inflammatory infiltrate along the particles, but at 42 days, it was resolved, mainly in BTP. In the birefringence analysis, BT and BTP, the percentage of red birefringence increased (9.14% to 20.98% and 7.21% to 27.57%, respectively), but green birefringence was similar in relation to 14 days (3.3% to 3.5% and 3.5% to 4.2%, respectively). The number of osteocytes in the neoformed bone matrix proportionally reduced in all evaluated groups. Immunostaining of bone morphogenetic protein (BMP—2/4), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) were higher in BCP and BTP when compared to the BC and BT groups (p < 0.05). An increased number of TRAP positive cells (tartrate resistant acid phosphatase) was observed in BT and BTP. We conclude that PBMT positively influenced the repair of bone defects filled with B and T.

Effects of low-level laser therapy on reducing pain, edema, and trismus after orthognathic surgery: a systematic review

The purpose of this study was to systematically review the scientific evidence of the effect of low-level laser therapy (LLLT) on the perception of pain, edema, and trismus after orthognathic surgery. The literature was searched in 11 databases (MedLine via PubMed, Scopus, LILACS, SciELO, Embase, Web of Science, Cochrane Library, and LIVIVO, OpenGrey, OADT, and OpenThesis), without restriction of publication year or language. This search aimed to identify randomized clinical trials comparing low-level laser therapy and placebo for controlling pain, edema, and trismus after orthognathic surgeries. Two reviewers extracted the data and assessed the individual risk of bias of the eligible studies using the Cochrane Collaboration Risk of Bias Tool (RoB, version 2.0). The initial search resulted in 808 articles, from which only five (total of 190 participants) were included in the qualitative synthesis. The studies were published from 2014 to 2020. Two presented a low risk of bias + in the mean mouth opening of all patients subjected to bimaxillary surgery who received LLLT. However, the other study found a significant difference in maximum mouth opening in the LLLT group at 14, 30, and 60 days after surgery. Based on limited evidence, LLLT was presented as an auxiliary tool for reducing pain and trismus after surgery. However, the reduction of edema is controversial due to the absence of measuring standardization.

Effect of Light-Emitting Diode Phototherapy on Allograft Bone After Open Sinus Lift Surgery: A Randomized Clinical Trial (Concurrent Parallel)

Introduction: Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses. Methods: This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients. Results: Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P >0.05). Conclusion: The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.

Benefits of Sebastiania hispida (Euphorbiaceae) extract and photobiomodulation therapy as potentially adjunctive strategies to be explored against snake envenoming

The purpose of this study was to assess the topic use of Sebastiania hispida extract and low-level gallium-arsenide laser irradiation (GaAs, 904 nm) to reduce the local myonecrosis and edema of Bothrops moojeni snake venom-injected gastrocnemius. Wistar rats receiving intramuscular venom injection (VBm) were compared with saline control (S) and envenomed rats receiving local exposure to plant extract (VExt) or laser irradiation (VL). The phytochemistry and thin-layer chromatography of S. hispida extract indicated the presence of phenolic compounds like gallic acid and flavonoids including quercetin. Gastrocnemius of VExt and VL groups had a significant reduction of edema and creatine kinase (CK) activities and a greater Myogenin (MyoG) expression compared to VBm group, with the plant extract efficacy better than laser exposure. Reduction of edema and serum CK activities reflects a lessening of muscle damage, whereas the increase of MyoG indicates myoblast differentiation and acceleration of muscle repair. The S. hispida richness in phenolic compounds and flavonoids, such as the light modulatory ability to triggering a multitude of cell signalings likely underlie the positive outcomes. Our findings suggest both treatments as potential auxiliary tools to be explored in clinical trials in combination with anti-venom therapy after Bothropic snakebites.

A smart LED therapy device with an automatic facial acne vulgaris diagnosis based on deep learning and internet of things application

In low-level laser therapy, providing an optimal dosage and proposing a proper diagnosis before dermatological treatment are essential to reduce the side effects and potential dangers. In this article, a smart LED therapy system for automatic facial acne vulgaris diagnosis based on deep learning and Internet of Things application is proposed. The main goals of this study were to (1) develop an LED therapy device with different power densities and LED grid control; (2) propose a deep learning model based on modified ResNet50 and YOLOv2 for an automatic acne diagnosis; and (3) develop a smartphone application for facial photography image capture and LED therapy parameter configuration. Furthermore, a healthcare Internet of Things (H-IoT) platform for the connectivity between smartphone apps, the cloud server, and the LED therapy device is proposed to improve the efficiency of the treatment process. Experiments were conducted on test data sets divided by a cross-validation method to verify the feasibility of the proposed LED therapy system with automatic facial acne detection. The obtained results evidenced the practical application of the proposed LED therapy system for automatic acne diagnosis and H-IoT-based solutions.

A Prospective Comparative Study of Pulsed High-Intensity Laser Therapy and Pulsed Electromagnetic Field on Chronic Nonspecific Low Back Pain

Objective: This study explored the different effects of pulsed high-intensity laser therapy (HILT) versus pulsed electromagnetic field (EMF) in the treatment of chronic nonspecific low back pain (ChNsLBP). Methods: Between August and December 2019, 51 ChNsLBP participants with a mean age of 35.2 ± 8.6 years were enrolled in this prospective comparative study. At random, they were divided into three groups, 17 in each; HILT, EMF, and controls. HILT group was recruited for Nd:YAG laser using the following parameters: a wavelength of 1064 nm, fluency of 610-810 mJ, frequency of 10-40 Hz, average power of 10.5 W, and 120 μs short pulse duration in scanning mode. All groups received the treatment twice a week for 8 consecutive weeks. They were assessed for the modified Oswestry disability index (MODI), pain disability index (PDI), visual analog scale (VAS), and lumbar flexion range of motion (flex ROM) before and after 8 weeks of study program. Results: The results showed greater improvement in the HILT group (VAS, PDI, MODI, and lumbar flex ROM, p = 0.001) than the EMF group (VAS, p = 0.002, PDI, p = 0.045, MODI, p = 0.002, and lumbar flex ROM, p = 0.042), with significant difference between the two groups in favor of the HILT group (p ˂ 0.05). Conclusions: Depending on the results of the study, both HILT and EMF are useful physiotherapy modalities in the treatment of ChNsLBP with HILT exhibiting better outcomes than EMF. Clinical recommendations should be highlighted to instigate the use of HILT in the management of musculoskeletal disorders, distinctively ChNsLBP.

The Use of Technology in the Management of Orthodontic Treatment-Related Pain

Orthodontic pain is one of the negatives associated with fixed orthodontic treatment that cannot be avoided. This pain usually comes around the wire placement period and gradually decreases once the endogenous analgesic mechanisms start functioning. Over the years, several treatment modalities have been utilized for relief from orthodontic pain, and these include mechanical, behavior modification, and pharmacological methods. However, in the last decade, there are several newer methods employing the use of technology that have come up and are being used for alleviating pain. From computerized indirect bonding to virtual treatment planning, technology has slowly become a vital part of an orthodontist's repertoire. The digital age is here, and orthodontics must embrace the use of technology to help improve the quality of life of patients.

Photobiomodulation Therapy on the Guided Bone Regeneration Process in Defects Filled by Biphasic Calcium Phosphate Associated with Fibrin Biopolymer

The aim is to evaluate the effects of photobiomodulation therapy (PBMT) on the guided bone regeneration process (GBR) in defects in the calvaria of rats filled with biphasic calcium phosphate associated with fibrin biopolymer. Thirty male Wistar rats were randomly separated: BMG (n = 10), defects filled with biomaterial and covered by membrane; BFMG (n = 10), biomaterial and fibrin biopolymer covered by membrane; and BFMLG (n = 10), biomaterial and fibrin biopolymer covered by membrane and biostimulated with PBMT. The animals were euthanized at 14 and 42 days postoperatively. Microtomographically, in 42 days, there was more evident bone growth in the BFMLG, limited to the margins of the defect with permanence of the particles. Histomorphologically, an inflammatory infiltrate was observed, which regressed with the formation of mineralized bone tissue. In the quantification of bone tissue, all groups had a progressive increase in new bone tissue with a significant difference in which the BFMLG showed greater bone formation in both periods (10.12 ± 0.67 and 13.85 ± 0.54), followed by BFMG (7.35 ± 0.66 and 9.41 ± 0.84) and BMG (4.51 ± 0.44 and 7.11 ± 0.44). Picrosirius-red staining showed greater birefringence of collagen fibers in yellow-green color in the BFMLG, showing more advanced bone maturation. PBMT showed positive effects capable of improving and accelerating the guided bone regeneration process when associated with biphasic calcium phosphate and fibrin biopolymer.

Three-Dimensional Assessment of Mandibular Condylar Volume and Position Subsequent to Twin Block Functional Therapy of Skeletal Class II Malocclusion Accompanied by Low-Level Laser Therapy

This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) on mandibular condylar volume and position following treatment of a Class II malocclusion with a twin block (TB) appliance employing cone beam computed tomography (CBCT). Twenty-four growing patients, aged 9–12 years, were randomly allocated into control and laser groups. All patients were treated with a TB appliance. The patients in the laser group were treated weekly with a gallium–aluminum–arsenide (GaAlAs) diode laser around the temporomandibular joint (TMJ) region for three months. CBCT images were obtained before and after TB therapy and the changes in TMJ and skeletal variables were evaluated and compared among and between the groups. In the laser group, the condylar volume of the right and left sides significantly increased by 213.3 mm³ and 231.2 mm³, respectively (p < 0.05), whereas in the control group it significantly increased by 225.2 mm³, and 244.2 mm³, respectively (p < 0.05), with forward and lateral positioning of both sides. Furthermore, effective mandibular, ramus, and corpus lengths were increased, which were not significant between the groups. Low-Level Laser therapy accomplished no considerable effect on mandibular condylar volume and position following the functional orthopedic treatment of skeletal Class II malocclusions using a TB appliance.

Short-term clinical efficacy of the pulsed Nd: YAG laser therapy on chronic nonspecific low back pain: A randomized controlled study

BACKGROUND

Chronic non-specific low back pain (LBP) is gradually increasing among populations worldwide and affects their activities. Recently, the Nd:YAG laser has been presented in the rehabilitation field.

OBJECTIVES

This study aims to explore the short-term effects of the Nd:YAG laser on chronic non-specific LBP individuals.

METHODS

Thirty-five individuals with chronic nonspecific LBP were included in the study from December 2019 to March 2020. Randomly, they were categorized to Nd:YAG group (n = 18) and sham laser as a control (n = 17) thrice weekly for a 6-week intervention. Modified Oswestry disability index (MODI), pain disability index (PDI), visual analogue scale (VAS), and lumbar flexion range of motion (ROM) have been assessed pre and post-6 weeks of the intervention.

RESULTS

Significant improvements were observed in the Nd:YAG group (MODI, P < .001; PDI, P = .007; VAS, P < .001; lumbar ROM, P = .002), whereas the sham group showed no significant changes (MODI, P = .451; PDI, P = .339; VAS, P = .107; lumbar ROM, P = .296) after 6-week intervention. Between-group comparisons showed significant differences in tending toward the Nd:YAG group (MODI, P < .001; PDI, P = .046; VAS, P < .001; lumbar ROM, P = .003).

CONCLUSIONS

Regarding the present study outcomes, short-term pulsed Nd:YAG laser (6 weeks) may reduce functional disabilities and pain intensity, and improve the lumbar flexion ROM in patients with chronic nonspecific LBP. Further well-designed randomized controlled studies with large sample sizes should be conducted regarding laser treatment.

Photobiomodulation Therapy (PBMT) Applied in Bone Reconstructive Surgery Using Bovine Bone Grafts: A Systematic Review

The use of low-level laser therapy (LLLT) with biomodulatory effects on biological tissues, currently called photobiomodulation therapy (PBMT), assists in healing and reduces inflammation. The application of biomaterials has emerged in bone reconstructive surgery, especially the use of bovine bone due to its biocompatibility. Due to the many benefits related to the use of PBMT and bovine bones, the aim of this research was to review the literature to verify the relationship between PBMT and the application of bovine bone in bone reconstruction surgeries. We chose the PubMed/MEDLINE, Web of Science, and Scopus databases for the search by matching the keywords: "Bovine bone AND low-level laser therapy", "Bovine bone AND photobiomodulation therapy", "Xenograft AND low-level laser therapy", and "Xenograft AND photobiomodulation therapy". The initial search of the three databases retrieved 240 articles, 18 of which met all inclusion criteria. In the studies concerning animals (17 in total), there was evidence of PBMT assisting in biomaterial-related conduction, formation of new bone, bone healing, immunomarker expression, increasing collagen fibers, and local inflammation reduction. However, the results disagreed with regard to the resorption of biomaterial particles. The only human study showed that PBMT with bovine bone was effective for periodontal regeneration. It was concluded that PBMT assists the process in bone reconstruction when associated with bovine bone, despite divergences between applied protocols.

Molecular impacts of photobiomodulation on bone regeneration: A systematic review

Photobiomodulation (PBM) encompasses a light application aimed to increase healing process, tissue regeneration, and reducing inflammation and pain. PBM is specifically aimed to modify the expression of cellular molecules; however, PBM impacts on cellular and molecular pathways especially in bone regenerative medicine have been investigated in scattered different studies. The purpose of the current study is to systematically review evidence on molecular impact of PBM on bone regeneration. A comprehensive electronic search in Medline, Scopus, EMBASE, EBSCO, Cochrane library, web of science, and google scholar was conducted from January 1975 to October 2018 limited to English language publications on administrations of photobiomodulation for bone regeneration which evaluated biological factors. In addition, hand search of selected journals was done to retrieve all articles. This systematic review was performed based on PRISMA guideline. Among these studies, five articles reported in vitro results, twelve articles were in vivo, and three of them were clinical trials. The data tabulated according to the type of markers (osteogenic markers, angiogenic markers, growth factors, and inflammation mediators). PBM's effects depend on many parameters which energy density is more important than the others. PBM can significantly enhance expression of osteocalcin, collagen, RUNX-2, vascular endothelial growth factor, bone morphogenic proteins, and COX-2. Although since the heterogeneity of the studies and their limitations, an evidence-based decision for definite therapeutic application of PBM is still unattainable, the findings of our review can help other researchers to ameliorate their study design and elect more efficient approach for their investigation.

Fibrin Sealant Derived from Human Plasma as a Scaffold for Bone Grafts Associated with Photobiomodulation Therapy

Fibrin sealants derived from human blood can be used in tissue engineering to assist in the repair of bone defects. The objective of this study was to evaluate the support system formed by a xenograft fibrin sealant associated with photobiomodulation therapy of critical defects in rat calvaria. Thirty-six rats were divided into four groups: BC (n = 8), defect filled with blood clot; FSB (n = 10), filled with fibrin sealant and xenograft; BCPBMT (n = 8), blood clot and photobiomodulation; FSBPBMT (n = 10), fibrin sealant, xenograft, and photobiomodulation. The animals were killed after 14 and 42 days. In the histological and microtomographic analysis, new bone formation was observed in all groups, limited to the defect margins, and without complete wound closure. In the FSB group, bone formation increased between periods (4.3 ± 0.46 to 6.01 ± 0.32), yet with lower volume density when compared to the FSBPBMT (5.6 ± 0.45 to 10.64 ± 0.97) group. It was concluded that the support system formed by the xenograft fibrin sealant associated with the photobiomodulation therapy protocol had a positive effect on the bone repair process.

The Impacts of Low-Level Laser Therapy - A Complementary Treatment in the Management of Side Effects After Implant Surgery

Introduction: One of the most important medical applications of laser is low-level laser therapy (LLLT). In this method, laser radiation penetrates easily into the target tissue. The aim of this study was to investigate whether LLLT can reduce the side effects of advanced implant surgery. Methods: In this triple-blind clinical trial, 30 patients aged 25 to 65 years were selected for implant insertion and divided into two groups. In the laser group, immediately after the surgery, 72 hours and 1 week after the surgery, the surgical site was irradiated with an 830 nm laser. The dose required for the laser therapy was 5 J/cm² . The degree of pain, facial swelling and wound healing were analyzed using statistical methods. Results: Our results showed that at 12, 24, 48, and 72 hours after the surgery, the pain level was reduced in the laser group compared with the placebo group (P<0.05). Swelling of the face was also significantly reduced 7 days after surgery in the laser group (P<0.05). The investigation on the recovery conditions of the surgical site showed that on the 3rd, 7th and 14th days after the surgery, higher levels of wound healing have been achieved (P<0.05). Conclusion: Our results suggest that laser, as a complementary therapy; can be used to reduce the severity and duration of pain. Also, laser can reduce facial swelling and accelerate wound healing.

Long-Term Effect of Pulsed Nd:YAG Laser in the Treatment of Patients with Rotator Cuff Tendinopathy: A Randomized Controlled Trial

OBJECTIVE

The purpose of the present study was to investigate the long-term effect of pulsed Nd:YAG laser on the treatment of rotator cuff tendinopathy.

METHODS

Sixty patients with rotator cuff tendinopathy participated and completed the study. The mean age was 50.2 ± 3.6 years. Participants were randomly assigned to one of two groups: the control group and the treatment group. Both groups were treated with an exercise program, in addition to the pulsed Nd:YAG laser received by the treatment group and the "sham" laser received by the control group, both for three sessions per week for 4 weeks. Outcome measures included pain, assessed by the visual analog scale, and range of motion (ROM), assessed using a traditional goniometer, while the shoulder pain and disability index were used to evaluate the functional recovery of the shoulder joint. Evaluation was carried out before treatment, immediately after treatment, 3 months posttreatment, and 6 months posttreatment. Statistical analyses were used to investigate the effect of interventions and to compare the study groups' pretreatment, posttreatment, and at follow-up points. The significance level was set to p < 0.05.

RESULTS

Pain was significantly decreased after treatment and at follow-up points, while ROM and shoulder functions were significantly improved after treatment and at follow-up intervals in both groups. The improvement was more significant in the treatment group than in the control group posttreatment and at follow-up intervals.

CONCLUSIONS

Pulsed Nd:YAG laser combined with an exercise program seems to be more effective in the treatment of patients with rotator cuff tendinopathy than a sham laser with exercises.

The influence of low level laser irradiation on vascular reactivity

PURPOSE

The mechanism of action of low level laser irradiation on tissues is unclear. Authors of publications present the positive clinical impact of low and medium power laser irradiation on vascular reactivity. The purpose of this study was to analyze the role of vascular endothelium in laser-induced constricted by endothelin-1 and phenylephrine.

MATERIALS AND METHODS

Experiments were performed on isolated and perfused rat tail arteries of weighing 250-350g male Wistar rats. Contractility of arteries as a response to endothelin-1 and phenylephrine was measured after exposure to laser stimulation (10, 30 and 110mW).

RESULTS

Laser irradiation inhibits vascular smooth muscle contraction induced by endothelin-1 and an alpha-adrenergic receptor agonist, phenylephrine proportionally to the laser power. Concentration-response curves were shifted to the right with significant reduction in maximal response. Laser irradiation at the power of 10mW, 30mW, and 110mW reduced the maximum response of arteries stimulated with phenylephrine sequentially to 88%, 72%, and 52%. Similar findings were observed during stimulation of endothelin-1. Laser irradiation at the power of 10mW, 30mW and 110mW resulted in maximal response respectively reduced to 94%, 62% and 38%.

CONCLUSION

Our results strongly suggest that during low level laser irradiation vascular smooth muscle cells reactivity is reduced, this effect is present in arteries with normal endothelium. The mechanism of action of laser biosimulation on tissues is unclear. Authors of publications present the positive clinical impact of low level laser irradiation on vascular reactivity.

In Vitro Influence of Low-Power Diode Laser Irradiation Time on Human Red Blood Cells

OBJECTIVE

The present study investigates whether the exposure to low-power diode laser induces denaturation in red blood cell (RBC) membrane protein composition, and determines the irradiation time for when denaturation of membrane protein process begins.

BACKGROUND

A low-energy laser has been used extensively in medical applications. Several studies indicated significant positive effects of laser therapy on biological systems. In contrast, other studies reported that laser induced unwanted changes in cell structure and biological systems. The present work studied the effect of irradiation time of low-power diode laser on the structure of membrane proteins of human RBCs.

MATERIALS AND METHODS

The RBC suspension was divided into five equal aliquots. One aliquot served as control. The remaining four aliquots were exposed to low-power diode laser (wave length = 650 nm, power = 50 mW) for 10, 20, 30, and 40 min, respectively. After each given time, the percentage of denatured RBCs was calculated in each sample as described later.

RESULTS

Irradiation of RBCs by this laser for 20 min did not cause any change in membrane protein composition. While increasing the irradiation time to 30 min caused denaturation of membrane proteins, resulting in the formation of cross-bonding in a considerable number of RBCs, and the percentage of denatured cells increased in a dose-dependent manner to the irradiation.

CONCLUSIONS

It can be concluded that the effect of low-power diode laser on RBC membrane protein structure depends on irradiation time.

In Vitro Effects of High-Intensity Laser Photobiomodulation on Equine Bone Marrow-Derived Mesenchymal Stem Cell Viability and Cytokine Expression

OBJECTIVE

This study aimed to examine the influence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on equine bone marrow-derived mesenchymal stem cell (MSC) viability, proliferation, and cytokine expression in vitro.

BACKGROUND

Photobiomodulation of cells using monochromatic light is a technique designed to influence cellular processes. Previous studies have shown dose-dependent effects of low-level laser irradiation on cell proliferation and cytokine expression in a range of cell types and species. Evidence for the influence of 1064 nm wavelength near-infrared irradiation on MSCs is sparse, and high-energy doses have shown inhibitory effects.

METHODS

MSC cultures from six horses were exposed to 1064 nm irradiation with an energy density of 9.77 J/cm² and a mean output power of 13.0 W for 10 sec. MSC viability and proliferation were evaluated through flow cytometry and real-time live cell analysis. Gene expression and cytokine production in the first 24 h after irradiation were analyzed through polymerase chain reaction (PCR), multiplex assay, and enzyme-linked immunosorbent assay.

RESULTS

No difference in viability was detected between irradiated and control MSCs. Irradiated cells demonstrated slightly lower proliferation rates, but remained within 3.5% confluence of control cells. Twenty-four hours after irradiation, irradiated MSCs demonstrated a significant increase in expression of interleukin (IL)-10 and vascular endothelial growth factor (VEGF) compared with control MSCs.

CONCLUSIONS

Under these irradiation parameters, equine MSCs remained viable and expressed increased concentrations of IL-10 and VEGF. IL-10 has an anti-inflammatory action by inhibiting the synthesis of proinflammatory cytokines at the transcriptional level. This response to 1064 nm irradiation shows promise in the photobiomodulation of MSCs to enhance their therapeutic properties.

Effects of photobiomodulation therapy on Bothrops moojeni snake-envenomed gastrocnemius of mice using enzymatic biomarkers

Bothropic venom contains a range of biologically active substances capable of causing severe local and systemic envenoming symptomatology within its victims. The snake anti-venom is effective against systemic effects but has no neutralizing effect against the fast developing local effects. Herein, mice gastrocnemius injected with Bothrops moojeni venom (40 μg/kg) or saline solution were irradiated with HeNe (632.8 nm) and GaAs (904 nm) lasers (daily energy density of 4 J/cm²; 0.03/0.21 power density; 0.07/0.16 spot size; 1.2/0.04 total energy, 1 cm off contact, for HeNe and GaAs lasers, respectively) and euthanized in periods ranging from 3 h to 21 days. Blood biochemistry for creatine kinase (CK), alkaline phosphatase (ALP), acid phosphatase (AP), lactate dehydrogenase (LDH), aspartate transaminase (AST), and myoglobin and histopathological analysis, for assessing the degree of myonecrosis and regeneration of gastrocnemius, were done at every time interval. GaAs laser promoted faster photobiomodulation therapy (PBMT) effects, and the GaAs group exhibited a better clinical outcome than the HeNe group. Within the GaAs group, the serum levels of CK, LDH, AP, AST, and myoglobin, which were increased by the physiological effects of the venom, were reduced to initial baseline before snake envenomation in less time than those irradiated by the HeNe laser. However, the group receiving irradiation from the HeNe laser returned the levels of ALP activity to baseline faster than those of the GaAs group. Histopathological analysis revealed enhanced muscle regeneration in mice groups treated with both lasers. PBM promoted by GaAs and HeNe showed well-developed centrally nucleate regenerating cells and an increased number of newly formed blood vessels when compared to unirradiated muscle. We therefore suggest that GaAs had the best outcomes likely derived from a deeper penetrating longer wavelength. We conclude that PMBT is a promising, non-invasive approach to be further tested in pre-clinical studies with a goal to further its clinical use in skeletal muscle recovery in snakebite victims.

Investigation of photobiomodulation potentiality by 635 and 809 nm lasers on human osteoblasts

Photobiomodulation (PBM) describes light-induced photochemical reactions achieved by the application of red or near infrared lasers/LED light with low energy densities. This noninvasive and painless method has been used in some clinical areas but controversial outcomes demand a skeptical look for its promising and potential effects. In this detailed in vitro study, the osteoblast cells were irradiated with 635 and 809 nm diode lasers at energy densities of 0.5, 1, and 2 J/cm². Cell viability, proliferation, bone formation, and osteoblast differentiation were evaluated by methylthiazole tetrazolium (MTT) assay, Alamar Blue assay, acridine orange/propidium iodide staining, alkaline phosphatase (ALP) activity, Alizarin red staining, and reverse-transcription polymerase chain reaction (RT-PCR) to test the expression of collagen type I, ALPL, and osteocalcin. The results indicate that studied energy doses have a transient effect (48 h after laser irradiation) on the osteoblast viability and proliferation. Similarly, laser irradiation did not appear to have any effect on ALP activity. These results were confirmed by RT-PCR analysis of osteoblast markers. This study suggests that several irradiation parameters and variations in the methods should be clearly established in the laboratory before laser treatment becomes a postulated application for bone tissue regeneration in clinical level.

Efficacy of pulsed high-intensity laser therapy on pain, functional capacity, and gait in children with haemophilic arthropathy

AIM

The aim of this study was to evaluate the effects of pulsed high-intensity laser therapy (HILT) on pain, functional capacity, and gait in children with haemophilia.

METHODS

Thirty children with haemophilia type A with ages ranging from 9 to 13 years were selected for this study. They were assigned randomly, into two equal treatment groups. The laser group received the traditional physical therapy programme plus active laser (total energy of 1500 J through three phases/3 sessions/week), whereas the placebo group received the same physical therapy programme plus placebo laser over three consecutive months. Baseline and post-treatment assessments used the visual analogue scale (VAS) to evaluate pain, a 6-min walk test (6MWT) to evaluate functional capacity, and the GAITRite^® system to evaluate gait parameters.

RESULTS

Children in the laser group showed significant improvement in pain, functional capacity, and gait parameters compared to those in the placebo group (p < 0.05). Post-treatment functional capacity for the laser and placebo groups were 316.6 ± 35.27 and 288 ± 43.3 m, respectively.

CONCLUSIONS

HILT is an effective modality in reducing pain, increasing functional capacity, and improving gait performance in children with haemophilic arthropathy. Implications for Rehabilitation Haemophilic arthropathy due to recurrent joint bleeding leads to physical, psychological, and socioeconomic problems in children with haemophilia and reduces their quality of life. Early physiotherapeutic interventions help to prevent and treat the sequelae of recurrent haemarthrosis. High-intensity laser therapy has been introduced as non-invasive and an effective physiotherapy modality for rapid pain control, with consequent improvement in children's quality of life. High-intensity laser therapy should be used as an adjunct to exercise programme in the rehabilitation of children with haemophilic arthropathy.

The effectiveness of low-level laser on postoperative pain and edema in secondary palatal operation

OBJECTIVE

The postoperative period after palatal surgery is usually very painful, requiring the use of pain-relieving drugs. Hence, the aim of this study was to evaluate the efficacy of Low-level laser therapy (LLLT) in post-operative pain control and edema after secondary palatal operations.

METHODS

A randomized double blinded clinical study on 20 children undergoing secondary palatal operations between 2013 and 2015 was done. Patients were randomly divided on two groups 10 patients each. In one group patients received local application of therapeutic laser immediately after surgery while patients received nothing in the control group. The mean age was 5.22 years ± 2.53 SD in the laser group and 6.42 years ± 0.76 in the control group. Postoperative pain was assessed by using visual analog scale scores and by recording the need of analgesics. The degree of postoperative edema was also recorded.

RESULTS

The pain scale showed significantly less postoperative pain in the laser group than in the control group from the first day (P-value = 0.006) to the 6th day (P-value = 0.014). The number of postoperative analgesic doses needed were significantly less in the laser group in the second and third days (P-value = 0.014). The postoperative edema was significantly higher in the control group from the 2nd (P-value = 0.004) to the 7th (P-value = 0.014) postoperative days.

CONCLUSIONS

Preliminary results showed that low-level laser therapy is effective in the reduction of postoperative pain and edema, and minimizing the need of analgesic medication after secondary palatal operations.

A Review of the Principles and Use of Lasers in Lower Limb Problems

Lasers present a unique light source with many clinical uses including a number of applications relevant to the lower extremity. In this article, the basic principles of lasers and their interactions with tissue will be reviewed. The article examines laser applications in skin and vascular disease including wound healing. The principles of laser safety are discussed, and relevant future developments are considered.

Using low level laser therapy to reduce early postoperative airway obstruction following modified Hogan's flap

INTRODUCTION AND OBJECTIVE

The most common postoperative complications of velopharyngeal insufficiency surgery are postoperative bleeding and airway obstruction or obstructive sleep apnoea. Consequently, the aim of this study was to evaluate the effect of low level laser therapy (LLLT) during the first postoperative days in children undergoing superiorly based pharyngeal flap (SBF) surgery.

MATERIALS AND METHODS

A randomized double blind clinical study on 30 children divided on two groups 15 patients each, who underwent SBF. LLLT was used in a group and the other was a control group. The study was conducted in academic tertiary care medical centres between 2013 and 2015. The degree of edema, oxygen saturation, occurrence of obstructive sleep apnoea (OSA) and steroid administration were recorded.

RESULTS

The mean of the average oxygen saturation was significantly less in the control group in the 1st and 2nd day as compared to the laser group. The need for oxygen and the incidence of OSA in the first 3 days were significantly higher in the control group as compared to the laser group. The degree of edema showed no significant difference in the first day but was significantly higher in the control group in the 2nd and 3rd days. Hence, the need of steroids was significantly higher in the control group in the first 3 days.

CONCLUSIONS

Preliminary results showed that low level laser therapy is effective in reducing the incidence of early postoperative airway obstruction after SBF operations.

Clinical Practice Patterns and Beliefs in the Management of Hamstrings Strain Injuries

CONTEXT

Hamstrings strain injuries (HSIs) are among the most commonly occurring injuries in sport and are top causes of missed playing time. Lingering symptoms, prolonged recovery, and a high reinjury rate (12%-34%) make HSI management a frustrating and challenging process for the athletic trainer (AT). The clinical practice patterns and opinions of ATs regarding HSI treatment and rehabilitation are unknown.

OBJECTIVE

To examine the frequency of method use and opinions about current HSI management among ATs.

DESIGN

Cross-sectional study.

SETTING

Survey administered to registrants at the 2013 National Athletic Trainers' Association Clinical Symposia and AT Expo.

PATIENTS OR OTHER PARTICIPANTS

A total of 1356 certified ATs (691 men, 665 women; age = 35.4 ± 10.5 years, time certified = 11.92 ± 9.75 years).

DATA COLLECTION AND ANALYSIS

A survey was distributed electronically to 7272 registrants and on paper to another 700 attendees. Validity and reliability were established before distribution. Participants reported demographic information and rated their frequency of treatment and rehabilitation method use and agreement with questions assessing confidence, satisfaction, and desire for better clinical practice guidelines. Exploratory factor analysis and principal axis factor analysis were used. We also calculated descriptive statistics and χ(2) tests to assess practice patterns.

RESULTS

The response rate was 17% (n = 1356). A 2-factor solution was accepted for factor analysis (r = 0.76, r = 0.70), indicating that ATs follow either a contemporary or traditional management style. Various practice patterns were evident across employment settings and years of clinical experience. Satisfaction with the current HSI management plan was high (73.6%), whereas confidence in returning an athlete to play was lower (62.0%). Rates of use were associated with belief in effectiveness for all methods assessed (P < .001). Higher confidence levels were associated with high use of several methods; we observed increased satisfaction (χ(2)2 = 22.5, P = .002) but not increased confidence levels in more experienced ATs.

CONCLUSIONS

Our study demonstrated the lack of consensus in HSI treatment and rehabilitation and the ATs' desire for better clinical practice guidelines. Future research in which multimodal strategies, including both traditional and contemporary methods, are studied is warranted for effective management of HSI.

"Quantum Leap" in Photobiomodulation Therapy Ushers in a New Generation of Light-Based Treatments for Cancer and Other Complex Diseases: Perspective and Mini-Review

OBJECTIVE

Set within the context of the 2015 International Year of Light and Light-Based Technologies,and of a growing and aging world population with ever-rising healthcare needs, this perspective and mini-review focuses on photobiomodulation (PBM) therapy as an emerging, cost-effective, treatment option for cancer (i.e., solid tumors) and other complex diseases, particularly, of the eye (e.g., age-related macular degeneration, diabetic retinopathy, glaucoma, retinitis pigmentosa) and the central nervous system (e.g., Alzheimer's and Parkinson's disease).

BACKGROUND DATA

Over the last decades, primary and secondary mechanisms of PBM have been revealed. These include oxygen-dependent and oxygen-independent structural and functional action pathways. Signal and target characteristics determine biological outcome, which is optimal (or even positive) only within a given set of parameters.

METHODS

This study was a perspective and nonsystematic literature mini-review.

RESULTS

Studies support what we describe as a paradigm shift or "quantum leap" in the understanding and use of light and its interaction with water and other relevant photo-cceptors to restore physiologic function.

CONCLUSIONS

Based on existing evidence, it is argued that PBM therapy can raise the standard of care and improve the quality of life of patients for a fraction of the cost of many current approaches. PBM therapy can, therefore,benefit large, vulnerable population groups, including the elderly and the poor, whilehaving a major impact on medical practice and public finances.

Lack of clinical evidence on low-level laser therapy (LLLT) on dental titanium implant: a systematic review

Low-level laser therapy (LLLT) has proved to have biostimulating effects on tissues over which they are applied, therefore accelerating the healing process. Most studies in implantology were focused on a reduction of the duration of osseointegration. There exist few articles analyzing the potential effects of these therapies on the osseointegration of titanium dental implants. The aim of this study was to assess the effect of LLLT on the interaction between the bone and the titanium dental implant and the methodological quality of the studies. We conducted an electronic search in PubMed, ISI Web, and Cochrane Library. From 37 references obtained, only 14 articles met the inclusion criteria. The analysis of the studies shows that most of the experiments were performed in animals, which have a high risk of bias from the methodological point of view. Only two studies were conducted in human bone under different conditions. Several protocols for the use of low-power laser and different types of laser for all studies analyzed were used. Although animal studies have shown a positive effect on osseointegration of titanium implants, it can be concluded that it is necessary to improve and define a unique protocol to offer a more conclusive result by meta-analysis.

Evaluation of Low-Level Laser Therapy in TMD Patients

Light amplification by stimulated emission of radiation (laser) is one of the most recent treatment modalities in dentistry. Low-level laser therapy (LLLT) is suggested to have biostimulating and analgesic effects through direct irradiation without causing thermal response. There are few studies that have investigated the efficacy of laser therapy in temporomandibular disorders (TMD), especially in reduced mouth opening. The case report here evaluates performance of LLLT with a diode laser for temporomandibular clicking and postoperative findings were evaluated in two cases of TMD patients. First patient had a history of limited mouth opening and pain in temporomandibular joint (TMJ) region since nine months. Second patient's main complaint was his restricted mouth opening, which was progressed in one year. LLLT was performed with a 685 nm red probed diode laser that has an energy density of 6.2 J/cm(2), three times a week for one month, and application time was 30 seconds (685 nm, 25 mW, 30 s, 0.02 Hz, and 6.2 J/cm(2)) (BTL-2000, Portative Laser Therapy Device). The treatment protocol was decided according to the literature. One year later patients were evaluated and there were no changes. This application suggested that LLLT is an appropriate treatment for TMD related pain and limited mouth opening and should be considered as an alternative to other methods.

A comparative study of red and blue light-emitting diodes and low-level laser in regeneration of the transected sciatic nerve after an end to end neurorrhaphy in rabbits

This study aimed at evaluating the effects of red and blue light-emitting diodes (LED) and low-level laser (LLL) on the regeneration of the transected sciatic nerve after an end-to-end neurorrhaphy in rabbits. Forty healthy mature male New Zealand rabbits were randomly assigned into four experimental groups: control, LLL (680 nm), red LED (650 nm), and blue LED (450 nm). All animals underwent the right sciatic nerve neurotmesis injury under general anesthesia and end-to-end anastomosis. The phototherapy was initiated on the first postoperative day and lasted for 14 consecutive days at the same time of the day. On the 30th day post-surgery, the animals whose sciatic nerves were harvested for histopathological analysis were euthanized. The nerves were analyzed and quantified the following findings: Schwann cells, large myelinic axons, and neurons. In the LLL group, as compared to other groups, an increase in the number of all analyzed aspects was observed with significance level (P < 0.05). This finding suggests that postoperative LLL irradiation was able to accelerate and potentialize the peripheral nerve regeneration process in rabbits within 14 days of irradiation.

Long-term effect of pulsed high-intensity laser therapy in the treatment of post-mastectomy pain syndrome: a double blind, placebo-control, randomized study

We assess the long-term effect of pulsed high-intensity laser therapy (HILT) in the treatment of the post-mastectomy pain syndrome (PMPS). A total of 61 women participated in this study (30 in the laser group and 31 in the placebo laser group), with a mean age of 53.56 ± 1.11 years. Patients who were randomly assigned to the laser group received HILT three times per week for 4 weeks, plus a routine physical therapy program (RPTP). The placebo laser group received placebo HILT plus RPTP. The outcomes measured were pain level by visual analog scale (VAS), shoulder range of motion (ROM), and quality of life (QOL). Statistical analysis was performed by ANOVA with repeated measures to compare the differences between baseline and post-treatment measurements and after 12 weeks of follow-up for both groups. The level of statistical significance was set at P < 0.05. Shoulder ROM significantly increased in the laser group after 4 weeks of treatment and after 12 weeks of follow-up compared with the placebo group. VAS results showed a significant decrease post-treatment in the laser group relative to the placebo group, and QOL results showed a significant improvement in the laser group compared with the placebo group and still improved after 12 weeks of follow-up. HILT combined with an RPTP appears to be more effective in patients with PMPS than a placebo laser procedure with RPTP.

The influence of laser radiation on human osteoblasts cultured on nanostructured composite substrates

BACKGROUND AND AIMS

Carbon-based nanomaterials such as carbon nanotubes, graphene oxide and graphene have been explored by researchers as well as the industry. Graphene is a new nanomaterial which has commercial and scientific advantages. Laser therapy has proven highly useful in biomedicine, with the use of different laser types and energies for distinct purposes. The low level laser therapy (LLLT) can have anti-inflammatory, analgesic and biostimulant effects. Recent research has shown that laser radiation has different effects on osteoblasts. The aim of this study was to identify the influence of laser radiation on human osteoblastic cells cultured on nanostructured composite substrates.

MATERIALS AND METHODS

Four types of substrates were created using colloidal suspensions of nanostructured composites in PBS at a concentration of 30 μg/ml. We used human osteoblasts isolated from patella bone pieces harvested during arthroplasty. Irradiation of osteoblasts cultured on nanostructured composite substrates was made with a semiconductor laser model BTL-10 having a wavelength of 830 nm. The proliferation activity of osteoblast cells was assessed using the MTT assay. After laser irradiation procedure the viability and proliferation of osteoblast cells were analyzed using fluorescein diacetate (FDA) staining.

RESULTS

The osteoblast cells viability and proliferation were evaluated with MTT assay at 30 minutes, 24 hours, 5 days and 10 days after laser irradiation. In the first 30 minutes there were no significant differences between the irradiated and non-irradiated cells. At 24 hours after laser irradiation procedure a significant increase of MTT values in case of irradiated osteoblasts cultivated on nanostructured hydroxyapatite, nanostructured hydroxyapatite with gold nanoparticles and 1.6% and 3.15% graphenes composites substrates was observed. A more marked proliferation rate was observed after 10 days of irradiation for irradiated osteoblasts seeded on nanostructured hydroxyapatite with gold nanoparticles and graphenes containing substrate. Using FDA staining we obtained very similar results with MTT test.

CONCLUSIONS

The association between the 830 nm laser irradiation of osteoblasts and their long-term cultivation of the nanostructured composite substrates induces the cell proliferation and differentiation and therefore it will be a useful alternative for bone regeneration therapy.

Short-term effects of high-intensity laser therapy on frozen shoulder: A prospective randomized control study

BACKGROUND

Frozen shoulder, which is characterized by shoulder pain and limitation of the range of motion (ROM), is a common disorder. High-intensity laser therapy (HILT) was recently introduced in the musculoskeletal therapeutic field.

OBJECTIVE

The objective of this study is to evaluate the clinical efficacy of HILT in patients with frozen shoulder.

DESIGN

A prospective randomized controlled study.

METHOD

Patients with frozen shoulder were randomly divided into 2 groups: a HILT group (n = 33) and a placebo group (n = 33). The treatment was administered 3 times per week on alternate days for 3 weeks. For all patients, the visual analog scale (VAS) for pain, VAS for satisfaction, and passive ROM were measured at baseline and 3, 8, and 12 weeks after the treatment.

RESULTS

The HILT group had a lower pain VAS score at 3 weeks (3.2 ± 1.7 vs. 4.3 ± 2.2, p = 0.033) and 8 weeks (2.2 ± 2.0 vs. 3.4 ± 2.7, p = 0.042), however, no statistically significant difference in the pain VAS was observed between the two groups at the final follow-up (12 weeks). No statistical difference in the ROM and the satisfaction VAS was observed between the 2 groups at serial follow-ups.

CONCLUSIONS

In management of frozen shoulder, HILT provided significant pain relief at 3 and 8 weeks, but not at the final follow-up time point. HILT is a noninvasive adjuvant treatment that can reduce pain in frozen shoulders. Further study is needed in order to optimize the dose and duration of HILT.