Orofacial evaluation of individuals with temporomandibular disorder after LED therapy associated or not of occlusal splint: a randomized double-blind controlled clinical study.

This study compared the effects of LED therapy associated with occlusal splint (OS) on the signs and symptoms of temporomandibular disorder (TMD). In this randomized, double-blind clinical trial, 70 TMD patients were randomly divided into six groups. The volunteers received the following treatments: Group 1 (G1) was the control and received only conventional therapy with OS; Group 2 (G2) was the placebo and received treatment with OS and therapy with LED (device turned off); Group 3 (G3) LED therapy (infrared,) once a week; Group 4 (G4) LED therapy (infrared) twice a week; Group 5 (G5) OS associated with LED (infrared) therapy (once a week); Group 6 (G6) received OS therapy plus infrared LED (two sessions per week). The patients were evaluated before, after, and 30 days after treatment. The pain intensity in masticatory system was recorded at each interval. The evaluation of the electromyographic signals (EMG) of the muscles (masseter and temporal) and blood lactate was performed before and after treatment. The associated groups presented better clinical results in relation to the control. The associated groups showed significant differences (p < 0.05) from control in the analysis of pain intensity and in decrease of the RMS value (EMG analysis). In the intragroup analysis, the volunteers in G6 exhibited a significant reduction (p < 0.05) in blood lactate. In conclusion, the association of LED therapy and OS presented superior results in relation to the isolated therapies, especially the protocol with two weekly sessions.

Long-term analyses of spastic muscle behavior in chronic poststroke patients after near-infrared low-level laser therapy (808 nm): a double-blinded placebo-controlled clinical trial.

Stroke results in impairment of basic motor functions, such as muscle weakness in limbs affected by spasticity, leading to peripheral fatigue and impaired functionality. The clinical use of photobiomodulation therapy (PBMT) has provided major advances in the treatment of muscular disorders and prevention of muscle fatigue. The aim of this study was to analyze the effects of two distinct therapies in biceps spasticity of chronic hemiparetic patients. We analyzed range of elbow motion, torque, electromyography, and mean spectral frequency after 10 sessions of PBMT (Laser 100 mW, 808 nm, 159.24 J/cm2/point, 5 J/point); PBMT active or placebo was associated with exoskeleton-assisted functional treatment. A double-blind placebo-controlled sequential clinical trial was conducted with 12 healthy volunteers and 15 poststroke patients who presented upper-limb spasticity. The healthy volunteers performed only the evaluation protocol, and the poststroke volunteers participated in three consecutive phases (PBMT, PBMT + exoskeleton, placebo + PBMT) with a washout period of 4 weeks between each phase. We could observe significant increases in range of elbow motion after PBMT from 57.7 ± 14 to 84.3 ± 27.6 degrees (p < 0.001). The root mean square (RMS) values also increased after PBMT + exoskeleton from 23.2 ± 15 to 34.9 ± 21 µV (p = 0.0178). Our results suggest that the application of PBMT may contribute to an increased range of elbow motion and muscle fiber recruitment, increases in muscle strength, and, hence, to increase signal conduction on spastic muscle fibers in spastic patients.

Effects of Therapy with Light Emitting Diode (LED) in the Calcaneal Tendon Lesions of Rats: A Literature Review.

The objective of this review was to analyze original articles about the effects of therapy with LED in experimental models of calcaneal tendon lesions of rats. The search was performed in the period from February to May 2018, in the following electronic databases: MEDLINE, SciELO, and LILACS, besides the Google Scholar, using the descriptors "Achilles tendon", "Rats", "LED", "Tendinopathy", and "Low-level Light Therapy", as well as their matching parts in the Portuguese and Spanish languages, related to and in association with the relevant terms to the content sought. From the descriptors used 215 works were found. After application of eligibility criteria 8 works were selected, in which positive results were found after the application of the LED. Regarding the main results found with phototherapy, we observed a significant reduction in inflammation. Only one article mentioned little reduction of inflammation. In relation to the number of sessions, there was wide variation, with an average of approximately 5 sessions every 24 hours. Studies in this review pointed out, therefore, positive results in the repair of the calcaneal tendon after therapy with irradiation LED; however, carrying out more experimental studies that help the standardization of parameters to be used in this therapy for further clinical studies becomes necessary.

Low-intensity LED therapy (λ 640 ± 20 nm) on saphenectomy healing in patients who underwent coronary artery bypass graft: a randomized, double-blind study.

Myocardial revascularization surgery (CABG) is the most appropriate treatment for coronary artery disease. Currently, the great challenge is to reduce postoperative complications, such as wound infections, dehiscence, pain, and patients' quality of life. The saphenectomy is the target of complications in 10% of cases, which can cause greater morbidity, time, and cost of hospitalization. Studies show that low-intensity laser or light-emitted diode (LED) therapy promotes positive biomodulation of the tissue repair process, culminating in a lower incidence of dehiscence, pain reduction, and improvement in quality of life. The objective of the present study was to evaluate clinically the saphenous tissue repair after LED therapy. Forty subjects of both genders who underwent CABG with extracorporeal circulation were randomly divided into two groups: the placebo (PG) and experimental (EG). The experimental group underwent low-intensity LED therapy (λ 640 ± 20 nm, 6 J/cm2) on saphenectomy. The tissue repair was analyzed by digital photogrammetry on the first and fifth postoperative day. The border closure was blindly evaluated by three researchers. The hematoma and hyperemia area was quantitatively analyzed using ImageJ© software. The results showed that in the experimental group, there were less bleeding points and no dehiscence in saphenectomy, as compared to the placebo group. There was also a smaller area of hematoma and hyperemia in the experimental group (p < 0.0009). These data lead to the conclusion that the type of phototherapy protocol employed can assist in tissue repair.

Evaluation of the therapeutic effects of led (λ627 ± 10 nm) on the initial phase of ankle sprain treatment: a randomised placebo-controlled clinical trial.

Various therapies for the treatment of sprains have emerged as advances occur in biomedical engineering and photobiology. Therapy with coherent and non-coherent light is a treatment modality for various musculoskeletal injuries. The main certified phototherapy benefits are the reduction of nociceptive processes and the modulation of the inflammatory process, among others. The objective of this study was to analyse the changes caused by the use of light-emitting diodes (LED) (λ627 ± 10 nm) with an energy density of 10 J/cm2 in 40 subjects divided into two groups (20 placebo and 20 LED). All of the volunteers had acute ankle sprains by inversion of grade II treated with the PRICE (protection, rest, ice, compression and elevation) technique and were treated for 6 days with LED therapy and LED therapy turned off (placebo). Pain assessment was performed on the 1st, 3rd and 6th days using the visual analogue scale (VAS) of pain, the McGill Pain Questionnaire and volumetry. The group treated with LED showed statistically decreased pain compared to the placebo group in both the VAS (85.79 vs 55.73%) and McGill questionnaire (83.33 vs 52.52%). The reduction of oedema in the LED group on the 3rd and 6th days after therapy was statistically superior to that in the placebo (p < 0.0001). Based on the results of this study, treatment with LED, using the tested dose, is effective for pain and oedema in the initial phase of ankle sprains.

Effects of Matricaria Recutita (L.) in the Treatment of Oral Mucositis.

OBJECTIVE: The objective of this study was to review the effects of the Matricaria recutita (L.) in the treatment of oral mucositis. METHODOLOGY: The online search was performed in the period from June 2016 to April 2018 by means of databases LILACS (Latin American and Caribbean Center on Health Sciences Information), SciELO (Scientific Electronic Library Online), and MEDLINE (Medical Literature Analysis and Retrieval System Online). The consultation was restricted to the years 1991 to 2018 with the aim of elucidating the effects of Matricaria recutita in the treatment of oral mucositis. RESULTS: The final sample consisted of 21 studies, of which 10 were developed in animals and 11 in humans, published from 1991 to 2017, with a total sample of 644 patients. The total number of patients treated with Matricaria included in 11 studies was 364, while in the control groups the total number was 280. In experimental studies, animal models used were rats and the sample size ranged between 36 and 105 animals submitted to the induction of oral mucositis, where 4 studies used an intraperitoneal injection of 5-fluorouracil, while 7 induced lesion in the mucosa. From the data collected, it should be noted that both studies with humans and with animals showed significant effects. In this way, there is strong evidence for the discussion on the therapy; however, it should be noted that more studies are developed in order to clarify the most appropriate protocol for the prevention and treatment of injuries. CONCLUSION: According to the results found in this study, Matricaria recutita appeared to be a promising alternative for the treatment of oral mucositis. However, due to the great variability in the various types of intervention, more controlled double-blind randomized clinical studies are necessary to ensure the best protocol for treating oral mucositis.

Effect of non-coherent infrared light (LED, λ945 ± 20 nm) on bone repair in diabetic rats-morphometric and spectral analyses.

Phototherapy using coherent light (lasers) and non-coherent light (light-emitting diodes (LEDs)) has been investigated for the purpose of biomodulation in biological tissues. Several effects can be expected, including pain moderation, biostimulation of cellular tropism, anti-inflammatory effects, regular circulatory stimulation, and tissue repair. The aim of this study was to evaluate the effect of LED (λ945 ± 20 nm, 48 mW) therapy on the regeneration process in femoral lesions of rats (Wistar). Seven irradiation sessions were held, with a 48-h interval between sessions. The animals were euthanised 14, 21, and 28 days after surgery. Bone samples were analysed by histomorphometry, micro X-ray fluorescence spectroscopy, scanning electron microscopy, and optical densitometry. The results demonstrated the effective positive influence of low-intensity LED therapy using the near-infrared region on the tissue repair process in diabetic animals, especially in the early stages of repair (14 and 21 days after surgery). It can be concluded that LED therapy positively influences bone formation in the early stages of the bone repair process in non-diabetic and diabetic animals, without causing changes in the optical density and volume of tissue in the final stages. No influence of LED therapy was observed on the percentage of calcium, percentage of phosphorus, Ca/P ratio, or optical mineral density in non-diabetic animals. However, increased mineral concentration was evident in the diabetic animals treated with the LED during the repair process.

Low-intensity laser (660 nm) on sternotomy healing in patients who underwent coronary artery bypass graft: a randomized, double-blind study.

The aim of this study was to analyze the healing effects of low-level laser therapy (LLLT) on the longitudinal sternotomy incisions of patients who underwent coronary artery bypass graft (CABG). The volunteers were randomized into three groups of equal size (n = 30): control, placebo, and laser (λ = 660 nm and spatial average energy fluency [SAEF] = 1.06 J/cm2). The patients in the laser group underwent irradiation on postoperative days 2, 4, 6, and 8, and their sternotomy incisions were photographed immediately after the surgery and 8 days later for analysis. Three researchers who were blinded to the patient treatment groups analyzed the incision photographs to assess hyperemia and wound closure on the day of hospital discharge (eighth postoperative day). The sternotomy incisions in the LLLT group demonstrated less hyperemia, incisional bleeding, and dehiscence (p ≤ 0.005).

Effects of low-level laser therapy (LLLT 808 nm) on lower limb spastic muscle activity in chronic stroke patients.

A cerebrovascular accident (CVA) may affect basic motor functions, including spasticity that may be present in the upper extremity and/or the lower extremity, post-stroke. Spasticity causes pain, muscle force reduction, and decreases the time to onset of muscle fatigue. Several therapeutic resources have been employed to treat CVA to promote functional recovery. The clinical use of low-level laser therapy (LLLT) for rehabilitation of muscular disorders has provided better muscle responses. Thus, the aim of this study was to evaluate the effect of the application of LLLT in spastic muscles in patients with spasticity post-CVA. A double-blind clinical trial was conducted with 15 volunteer stroke patients who presented with post-stroke spasticity. Both males and females were treated; the average age was 51.5 ± 11.8 years old; the participants entered the study ranging from 11 to 48 months post-stroke onset. The patients participated in three consecutive phases (control, placebo, and real LLLT), in which all tests of isometric endurance of their hemiparetic lower limb were performed. LLLT (diode laser, 100 mW 808 nm, beam spot area 0.0314 cm(2), 127.39 J/cm(2)/point, 40 s) was applied before isometric endurance. After the real LLLT intervention, we observed significant reduction in the visual analogue scale for pain intensity (p = 0.0038), increased time to onset of muscle fatigue (p = 0.0063), and increased torque peak (p = 0.0076), but no significant change in the root mean square (RMS) value (electric signal in the motor unit during contraction, as obtained with surface electromyography). Our results suggest that the application of LLLT may contribute to increased recruitment of muscle fibers and, hence, to increase the onset time of the spastic muscle fatigue, reducing pain intensity in stroke patients with spasticity, as has been observed in healthy subjects and athletes.

Immediate effects of low-intensity laser (808 nm) on fatigue and strength of spastic muscle.

The cerebrovascular accident (CVA), high-impact disease II, affects the basic functions of the limbs, leading to changes of sensory, language, and motor functions. The search for resources that minimize the damage caused by this disease grows every day. The clinical use of low-intensity laser therapy (LILT) has provided major breakthroughs in the treatment of muscular disorders and prevention of muscle fatigue. Thus, the objective of the present study is to analyze the answers and immediate adaptations of the rectus femoris and vastus medialis of spastic hemiparetic patients, facing the increase in peak torque and triggering muscle fatigue, after application of LILT. Double-blind clinical trials were conducted with 15 volunteers post-CVA with spasticity, of both genders, between 40 and 80 years old. To this end, the volunteers went through three consecutive stages of rating (control, placebo, and laser). All performed tests of isometric contraction on the patient's hemiparetic side. Significant differences were observed with regard to the increase in muscle performance (p = 0.0043) and the reduction in blood lactate concentration (p < 0.0001) of the post-LILT muscles. The LILT (diode laser, l100 mW 808 nm, 4.77 J/cm(2)/point, 40 s/AP) can be employed during and after spastic muscle-strengthening exercises, contributing to the improvement of motor function of the patient. After application of LILT, we found increased torque as well as decreased in lactate level in patients with spasticity.

"Low-intensity laser therapy effect on the recovery of traumatic spinal cord injury".

Scientific advances have been made to optimize the healing process in spinal cord injury. Studies have been developed to obtain effective treatments in controlling the secondary injury that occurs after spinal cord injury, which substantially changes the prognosis. Low-intensity laser therapy (LILT) has been applied in neuroscience due to its anti-inflammatory effects on biological tissue in the repairing process. Few studies have been made associating LILT to the spinal cord injury. The objective of this study was to investigate the effect of the LILT (GaAlAs laser-780 nm) on the locomotor functional recovery, histomorphometric, and histopathological changes of the spinal cord after moderate traumatic injury in rats (spinal cord injury at T9 and T10). Thirty-one adult Wistar rats were used, which were divided into seven groups: control without surgery (n = 3), control surgery (n = 3), laser 6 h after surgery (n = 5), laser 48 h after surgery (n = 5), medullar lesion (n = 5) without phototherapy, medullar lesion + laser 6 h after surgery (n = 5), and medullar lesion + laser 48 h after surgery (n = 5). The assessment of the motor function was performed using Basso, Beattie, and Bresnahan (BBB) scale and adapted Sciatic Functional Index (aSFI). The assessment of urinary dysfunction was clinically performed. After 21 days postoperative, the animals were euthanized for histological and histomorphometric analysis of the spinal cord. The results showed faster motor evolution in rats with spinal contusion treated with LILT, maintenance of the effectiveness of the urinary system, and preservation of nerve tissue in the lesion area, with a notorious inflammation control and increased number of nerve cells and connections. In conclusion, positive effects on spinal cord recovery after moderate traumatic spinal cord injury were shown after LILT.

The effects of LED emissions on sternotomy incision repair after myocardial revascularization: a randomized double-blind study with follow-up.

This study aimed to analyze the effects of light-emitting diode (LED) therapy on sternotomy pain and healing in patients who underwent coronary artery bypass grafting (CABG). The patients were followed for 6 months after the surgery to determine their dehiscence. This study was conducted with 90 volunteers who electively submitted to CABG. The volunteers were randomly allocated into three different groups of equal size: LED (λ of 640 ± 20 nm and spatial average energy fluency of 1.2 J/cm(2) during hospitalization), placebo, or control. The outcomes assessed were pain when coughing by a visual analog scale (VAS) and the McGill questionnaire and sternotomy healing by clinical assessment and photographical register end interpretation. The LED group had better pain reduction, as indicated by both the VAS and the McGill questionnaire (number of words chosen and pain index) (p ≤ 0.05), on days 6 and 8 after hospital discharge compared to the placebo and control groups. One month after surgery, almost no individual mentioned pain when coughing. Three researchers blindly analyzed the incision photographs to determine hyperemia and wound closure, and they found that the LED group had both less hyperemia and less incision bleeding or dehiscence. The LED therapy (640 nm) had an analgesic effect on the sternotomies of patients who underwent CABG, increasing their incision healing and preventing dehiscence.

Digital photogrammetry and histomorphometric assessment of the effect of non-coherent light (light-emitting diode) therapy (λ640 ± 20 nm) on the repair of third-degree burns in rats.

Recent studies have demonstrated the efficacy of coherent light therapy from the red region of the electromagnetic spectrum on the tissue-healing process. This study analysed the effect of non-coherent light therapy (light-emitting diode-LED) with or without silver sulfadiazine (sulpha) on the healing process of third-degree burns. In this study, 72 rats with third-degree burns were randomly divided into six groups (n = 12): Gr1 (control), Gr2 (non-contact LED), Gr3 (contact LED), Gr4 (sulfadiazine), Gr5 (sulfadiazine + non-contact LED) and Gr6 (sulfadiazine + contact LED). The groups treated with LED therapy received treatment every 48 h (λ = 640 ± 20 nm, 110 mW, 16 J/cm(2); 41 s with contact and 680 s without contact). The digital photometric and histomorphometric analyses were conducted after the burn occurred. The combination of sulpha and LED (contact or non-contact) improved the healing of burn wounds. These results demonstrate that the combination of silver sulfadiazine with LED therapy (λ = 640 ± 20 nm, 4 J/cm(2), without contact) improves healing of third-degree burn wounds, significantly reduces the lesion area and increases the granulation tissue, increases the number of fibroblasts, promotes collagen synthesis and prevents burn infections by accelerating recovery.

Phototherapy effect on the muscular activity of regular physical activity practitioners.

Clinical investigations have demonstrated the effectiveness of phototherapy on the muscle activity. The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on the tibialis anterior muscle of regular physical activity practitioners by electromyographic, biomechanical, and biochemical (lactate) analysis. Double-blind controlled clinical trials were conducted with 12 healthy females, regular physical activity practitioners, between 18 and 30 years. The LLLT application (780 nm, 30 mW, 0.81 J/point, beam area of 0.2 cm(2), 27 s, ≈ 29 points) in the tibialis anterior muscle occurred after the delimitation of the points on every 4 cm(2) was held. It was observed that (a) a significant torque increase (p < 0.05) post-LLLT compared to the values after placebo therapy at the beginning of resistance exercise, (b) both muscle torque (isokinetic) and median frequency (EMG) showed a faster decay of the signals collected after placebo and laser treatment when compared to control values, (c) no significant change in torque in the strength test of five repetitions, (d) a significant muscle activity decrease (p < 0.05) after laser therapy compared to control values, and (e) an increase in lactate levels post-LLLT (p < 0.05) after 30 min of exercise. It is concluded that the LLLT increased the muscle torque at the beginning of the exercise and maintained the levels of lactate after resistance exercise. Therefore, the LLLT with the parameters used in this study can be utilized in rehabilitation to improve muscle performance in elite athletes.

The effect of two phototherapy protocols on pain control in orthodontic procedure--a preliminary clinical study.

Phototherapy with low-level coherent light (laser) has been reported as an analgesic and anti-inflammatory as well as having a positive effect in tissue repair in orthodontics. However, there are few clinical studies using low-level LED therapy (non-coherent light). The aim of the present study was to analyze the pain symptoms after orthodontic tooth movement associated with and not associated with coherent and non-coherent phototherapy. Fifty-five volunteers (mean age = 24.1 ± 8.1 years) were randomly divided into four groups: G1 (control), G2 (placebo), G3 (protocol 1: laser, InGaAlP, 660 nm, 4 J/cm(2), 0.03 W, 25 s), G4 (protocol 2: LED, GaAlAs, 640 nm with 40 nm full-bandwidth at half-maximum, 4 J/cm(2), 0.10 W, 70 s). Separators were used to induce orthodontic pain and the volunteers pain levels were scored with the visual analog scale (VAS) after the separator placement, after the therapy (placebo, laser, or LED), and after 2, 24, 48, 72, 96, and 120 h. The laser group did not have statistically significant results in the reduction of pain level compared to the LED group. The LED group had a significant reduction in pain levels between 2 and 120 h compared to the control and the laser groups. The LED therapy showed a significant reduction in pain sensitivity (an average of 56%), after the orthodontic tooth movement when compared to the control group.

Effect of Modified Laser Transcutaneous Irradiation on Pain and Quality of Life in Patients with Diabetic Neuropathy.

Background: Diabetic neuropathy (DN) is one of the major complications developed by individuals with diabetes mellitus. DN is responsible for a high morbidity and mortality rate and impacts the public health and medical assistance resources. Intradermic laser irradiation on blood (ILIB) consists of the application of light beams on the radial arterial, providing anti-inflammatory and vasodilator effects, antiarrhythmic action, reduction of glucose, and stabilization of the hormonal and immunological systems. These effects help to maintain the physiological dynamics of the body. Objective: The goal of this research was to evaluate the effects of ILIB to relieve pain and improve the quality of life in DN patients. The sample comprised 30 diabetic volunteers with DN, randomly distributed into 3 groups: Control-conventional treatment; ILIB-100 mW, 660 ± 10 nm, 30 applications in total, divided into 3 stages of 10 applications, 30 min each, daily, with a 20-day interval between each stage; SILIB-same protocol described for ILIB, with the equipment switched off. Before and after the application of the therapeutic protocols, all volunteers were evaluated by the following instruments: Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), visual analog scale, Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), and PAIN DETECT scale. Collected data were statistically analyzed with a 95% confidence interval, p < 0.05. Results: The ILIB group presented significantly lower pain levels and a better quality of life compared with the control and SILIB groups. Conclusions: This study demonstrated that ILIB therapy was effective in reducing pain and improving quality of life in patients with DN.

Effect of low intensity photobiomodulation associated with norbixin-based poly (hydroxybutyrate) membrane on post-tenotomy tendon repair. In vivo study.

PURPOSE: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. METHODS: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. RESULTS: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p<0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p<0.0001) and L3 (p<0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. CONCLUSION: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.

Effect of norbixin-based poly(hydroxybutyrate) membranes on the tendon repair process after tenotomy in rats.

PURPOSE: To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair. METHODS: Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically. RESULTS: Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107). CONCLUSION: Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.

Comparative analysis of coherent light action (laser) versus non-coherent light (light-emitting diode) for tissue repair in diabetic rats.

The already known benefits produced by the interaction of coherent light (laser) with biologic tissues determine its use as an adjuvant in the treatment of several complications associated with diabetes. Non-coherent light, such as that emitted by light emitting diodes (LEDs), becomes a promising alternative, because of its low cost and easy handling in these applications. Thirty-six rats were given surgical dorsum lesions. The lesions for the control group did not receive any supporting therapy. The other groups were irradiated only once, 30 min after the establishment of the lesion, with LED (640 nm with 40 nm full bandwidth at half maximum) or laser (660 nm). The histomorphological and histomorphometrical parameters were quantified. The coherent and non-coherent lights produced similar effects during a period of 168 h after the lesions had been made. For the group composed of diabetic animals, 72 h after creation of the lesion, it was observed that the therapy with LEDs had been more efficient than that with the laser in the reduction of the wounds' diameters.

Effect of laser therapy (660 nm) on recovery of the sciatic nerve in rats after injury through neurotmesis followed by epineural anastomosis.

The aim of this study was to analyze the influence of aluminum gallium arsenide (AlGaAs) laser (660 nm) on the myelin sheath and functional recovery of the sciatic nerve in rats. The sciatic nerves of 12 Wistar rats were subjected to injury through neurotmesis and epineural anastomosis, and the animals were divided into two groups: group 1 was the control and group 2, underwent low-level laser therapy (LLLT). After the injury, AlGaAs laser at 660 nm, 4 J/cm(2), 26.3 mW and beam area of 0.63 cm(2) was administered to three equidistant points on the injury for 20 consecutive days. In the control group the mean area of the myelin impairment was 0.51 (+/- 0.11) on day 21 after the operation, whereas this value was 1.31 (+/- 0.22) in the LLLT group. Student's t-test revealed a P value = 0.0229 for the mean area values of the myelin sheath between the LLLT and control groups. Comparison of the sciatic functional index (SFI) showed that there was no significant difference between the pre-lesion value in the laser therapy group and the control group. The use of AlGaAs laser (660 nm) provided significant changes to the morphometrically assessed area of the myelin sheath, but it did not culminate in positive results for functional recovery in the sciatic nerve of the rats after injury through neurotmesis.