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

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

Effect of GaAlAs low-level laser therapy on mouth opening after orthognathic surgery.

To evaluate low-level laser therapy (LLLT) as an adjunct to enhance postoperative mouth opening after orthognathic surgery. Prospective clinical trial of 82 patients allocated into an intervention group (laser, LG) and a control group (no laser, CG) and subgroups according to the procedure type : (1) surgically assisted rapid maxillary expansion (SARME); (2) maxillary surgery; (3) mandibular surgery; or (4) bimaxillary surgery. LG patients received LLLT immediately after surgery and every 24 h thereafter for 3 days, using a gallium-aluminum-arsenide (GaAlAs) diode laser (780 nm, 28 spots, 14 on each side of the face, output power 2 J/spot). Maximum mouth opening was measured using digital calipers at five time points: preoperative baseline and postoperative days 2, 7, 14, and 21. ANOVA was used to evaluate difference in mouth opening across groups. Significance was accepted at P ≤ 0.05. Final average mouth opening differed between women (GL1 = 94.24%, GC1 = 89.54%, GL2 = 69.39%; GC2 = 68.46%; GL3 = 65.11%; GC3 = 58.64%; GL4 = 61.85%; GC4 = 57.11%) and men (GL1 = 86.92%, GC1 = 102.44%, GL2 = 77.56%; GC2 = 81.65%; GL3 = 80.29%; GC3 = 67.63%; GL4 = 66.93%; GC4 = 55.31%). There were no significant differences between the SARME and isolated maxillary/mandibular surgery groups. In the bimaxillary groups, average mouth opening was increased in all patients who received LLLT, significantly so in male patients. LLLT with a GaAlAs diode laser (780 nm) did not affect postoperative mouth opening after SARME, isolated maxillary surgery, or isolated mandibular surgery. However, it improved mouth opening in men who had undergone bimaxillary orthognathic surgery.

Laser photobiomodulation in pressure ulcer healing of human diabetic patients: gene expression analysis of inflammatory biochemical markers.

Pressure ulcers (PU) are wounds located mainly on bone surfaces where the tissue under pressure suffers ischemia leading to cellular lesion and necrosis , its causes and the healing process depend on several factors. The aim of this study was evaluating the gene expression of inflammatory/reparative factors: IL6, TNF, VEGF, and TGF, which take part in the tissue healing process under effects of low-level laser therapy (LLLT). In order to perform lesion area analysis, PUs were photographed and computer analyzed. Biochemical analysis was performed sa.mpling ulcer border tissue obtained through biopsy before and after laser therapy and quantitative real-time PCR (qRT-PCR) analysis. The study comprised eight individuals, mean age sixty-two years old, and sacroiliac and calcaneous PU, classified as degree III and IV according to the National Pressure Ulcer Advisory Panel (NPUAP). PUs were irradiated with low-level laser (InGaAIP, 100 mW, 660 nm), energy density 2 J/cm2, once a day, with intervals of 24 h, totaling 12 applications. The lesion area analysis revealed averaged improvement of the granulation tissue size up to 50% from pre- to post-treatment. qRT-PCR analysis revealed that IL6 values were not significantly different before and after treatment, TNF gene expression was reduced, and VEFG and TGF-ß gene expression increased after treatment. After LLLT, wounds presented improvement in gross appearance, with increase in factors VEFG and TGF-ß, and reduction of TNF; despite our promising results, they have to be analyzed carefully as this study did not have a control group.

High doses of laser phototherapy can increase proliferation in melanoma stromal connective tissue.

It is well established that laser phototherapy (LP) is contraindicated directly over cancer cells, due to its bio modulatory effects in cell and blood vessel proliferation. The aim of the present study was to analyze the influence of typical low-level laser therapy (LLLT) and high intensity laser therapy (HILT) and an in-between dose of 9 J on collagen fibers and blood vessels content in melanoma tumors (B16F10) implanted in mice. Melanoma tumor cells were injected in male Balb C mice which were distributed in four groups: control (no irradiated) or irradiated by 3, 9, or 21 J (150; 450, or 1050 J/cm2). LP was performed in daily sessions for 3 days with a InGaAlP-660 nm (mean output: 50 mW, spot size: 2 mm2). Tumor volume was analyzed using (1) picrosirius staining to quantify collagen fibers content and (2) Verhoeff's method to quantify blood vessels content. Tumor growth outcome measured in the 3-J group was not significantly different from controls. Nine and 21-J groups, presented significant and dose-dependent increases in tumor volume. Quantitative analysis of the intensity of collagen fibers and their organization in stroma and peri-tumoral microenvironment showed significant differences between irradiated and control group. Blood vessels count of 21-J group outnumbered the other groups. High doses (≥ 9 J) of LP showed a dose-dependent tumor growth, different collagen fibers characteristics, and eventually blood vessel growth, while a typical LLLT dose (3 J) appeared harmless on melanoma cell activity.

Photobiomodulation therapy protects skeletal muscle and improves muscular function of mdx mice in a dose-dependent manner through modulation of dystrophin.

This study aimed to analyze the protective effects of photobiomodulation therapy (PBMT) with combination of low-level laser therapy (LLLT) and light emitting diode therapy (LEDT) on skeletal muscle tissue to delay dystrophy progression in mdx mice (DMD mdx ). To this aim, mice were randomly divided into five different experimental groups: wild type (WT), placebo-control (DMD mdx ), PBMT with doses of 1 J (DMD mdx ), 3 J (DMD mdx ), and 10 J (DMD mdx ). PBMT was performed employing a cluster probe with 9 diodes (1 x 905nm super-pulsed laser diode; 4 x 875nm infrared LEDs; and 4 x 640nm red LEDs, manufactured by Multi Radiance Medical®, Solon - OH, USA), 3 times a week for 14 weeks. PBMT was applied on a single point (tibialis anterior muscle-bilaterally). We analyzed functional performance, muscle morphology, and gene and protein expression of dystrophin. PBMT with a 10 J dose significantly improved (p < 0.001) functional performance compared to all other experimental groups. Muscle morphology was improved by all PBMT doses, with better outcomes with the 3 and 10 J doses. Gene expression of dystrophin was significantly increased with 3 J (p < 0.01) and 10 J (p < 0.01) doses when compared to placebo-control group. Regarding protein expression of dystrophin, 3 J (p < 0.001) and 10 J (p < 0.05) doses also significantly showed increase compared to placebo-control group. We conclude that PBMT can mainly preserve muscle morphology and improve muscular function of mdx mice through modulation of gene and protein expression of dystrophin. Furthermore, since PBMT is a non-pharmacological treatment which does not present side effects and is easy to handle, it can be seen as a promising tool for treating Duchenne's muscular dystrophy.

Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats-part 1: morphological and functional aspects.

Musculoskeletal injuries are very frequent and are responsible for causing pain and impairment of muscle function, as well as significant functional limitations. In the acute phase, the most prescribed treatment is with non-steroidal anti-inflammatory drugs (NSAIDs), despite their questionable effectiveness. However, the use of photobiomodulation therapy (PBMT) in musculoskeletal disorders has been increasing in the last few years, and this therapy appears to be an interesting alternative to the traditional drugs. The objective of the present study was to evaluate and compare the effects of PBMT, with different application doses, and topical NSAIDs, under morphological and functional parameters, during an acute inflammatory process triggered by a controlled model of musculoskeletal injury induced via contusion in rats. Muscle injury was induced by means of a single trauma to the animals' anterior tibialis muscle. After 1 h, the rats were treated with PBMT (830 nm; continuous mode, with a power output of 100 mW; 3.57 W/cm2; 1 J-35.7 J/cm2, 3 J-107.1 J/cm2, and 9 J-321.4 J/cm2; 10, 30, and 90 s) or diclofenac sodium for topical use (1 g). Morphological analysis (histology) and functional analysis (muscle work) were performed, 6, 12, and 24 h after induction of the injury. PBMT, with all doses tested, improved morphological changes caused by trauma; however, the 9 J (321.4 J/cm2) dose was the most effective in organizing muscle fibers and cell nuclei. On the other hand, the use of diclofenac sodium produced only a slight improvement in morphological changes. Moreover, we observed a statistically significant increase of muscle work in the PBMT 3 J (107.1 J/cm2) group in relation to the injury group and the diclofenac group (p < 0.05). The results of the present study indicate that PBMT, with a dose of 3 J (107.1 J/cm2), is more effective than the other doses of PBMT tested and NSAIDs for topical use as a means to improve morphological and functional alterations due to muscle injury from contusion.

Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats-part 2: biochemical aspects.

Muscle injuries trigger an inflammatory process, releasing important biochemical markers for tissue regeneration. The use of non-steroidal anti-inflammatory drugs (NSAIDs) is the treatment of choice to promote pain relief due to muscle injury. NSAIDs exhibit several adverse effects and their efficacy is questionable. Photobiomodulation therapy (PBMT) has been demonstrated to effectively modulate inflammation induced from musculoskeletal disorders and may be used as an alternative to NSAIDs. Here, we assessed and compared the effects of different doses of PBMT and topical NSAIDs on biochemical parameters during an acute inflammatory process triggered by a controlled model of contusion-induced musculoskeletal injury in rats. Muscle injury was induced by trauma to the anterior tibial muscle of rats. After 1 h, rats were treated with PBMT (830 nm, continuous mode, 100 mW of power, 35.71 W/cm2; 1, 3, and 9 J; 10, 30, and 90 s) or diclofenac sodium (1 g). Our results demonstrated that PBMT, 1 J (35.7 J/cm2), 3 J (107.1 J/cm2), and 9 J (321.4 J/cm2) reduced the expression of tumor necrosis factor alpha (TNF-α) and cyclooxygenase-2 (COX-2) genes at all assessed times as compared to the injury and diclofenac groups (p < 0.05). The diclofenac group showed reduced levels of COX-2 only in relation to the injury group (p < 0.05). COX-2 protein expression remained unchanged with all therapies except with PBMT at a 3-J dose at 12 h (p < 0.05 compared to the injury group). In addition, PBMT (1, 3, and 9 J) effectively reduced levels of cytokines TNF-α, interleukin (IL)-1ß, and IL-6 at all assessed times as compared to the injury and diclofenac groups (p < 0.05). Thus, PBMT at a 3-J dose was more effective than other doses of PBMT and topical NSAIDs in the modulation of the inflammatory process caused by muscle contusion injuries.

The low level laser therapy (LLLT) operating in 660 nm reduce gene expression of inflammatory mediators in the experimental model of collagenase-induced rat tendinitis.

Tendinopathy is a common disease with a variety of treatments and therapies. Laser therapy appears as an alternative treatment. Here, we investigate the effects of laser irradiation in an experimental model of tendinitis induced by collagenase injection on rats' Achilles tendon, verifying its action in important inflammatory markers. Male Wistar rats were used and divided into five groups: control saline (C), non-treated tendinitis (NT) and tendinitis treated with sodium diclofenac (D) or laser (1 J) and (3 J). The tendinitis was induced by collagenase (100 µg/tendon) on the Achilles tendon, which was removed for further analyses. The gene expression for COX-2; TNF-α; IL-6; and IL-10 (RT-PCR) was measured. The laser irradiation (660 nm, 100 mW, 3 J) used in the treatment of the tendinitis induced by collagenase in Achilles tendon in rats was effective in the reduction of important pro-inflammatory markers such as IL-6 and TNF-α, becoming a promising tool for the treatment of tendon diseases.

The thermal impact of phototherapy with concurrent super-pulsed lasers and red and infrared LEDs on human skin.

From the very first reports describing the method of action of phototherapy, the effects have been considered to be the result of photochemical and photophysical interactions between the absorbed photons and tissue and not related to secondary changes in tissue or skin temperature. However, thermal effects have been recently reported in dark pigmented skin when irradiated with single wavelengths of 810 and 904 nm of low-level laser therapy (LLLT) devices even with doses that do not exceed those recommended by the World Association of Laser Therapy (WALT). The aim of this study was to evaluate the thermal impact during the concurrent use of pulsed red and infrared LEDs and super-pulsed lasers when applied to light, medium, and dark pigmented human skin with doses typically seen in clinical practice. The study evaluated the skin temperature of 42 healthy volunteers (males and females 18 years or older, who presented different pigmentations, stratified according to Von Luschan's chromatic scale) via the use of a thermographic camera. Active irradiation was performed with using the multi-diode phototherapy cluster containing four 905-nm super-pulsed laser diodes (frequency set to 250 Hz), four 875-nm infrared-emitting diodes, and four 640-nm LEDs (manufactured by Multi Radiance Medical™, Solon, OH, USA). Each of the four doses were tested on each subject: placebo, 0 J (60 s); 10 J (76 s); 30 J (228 s); and 50 J (380 s). Data were collected during the last 5 s of each dose of irradiation and continued for 1 min after the end of each irradiation. No significant skin temperature increases were observed among the different skin color groups (p > 0.05), age groups (p > 0.05), or gender groups (p > 0.05). Our results indicate that the concurrent use of super-pulsed lasers and pulsed red and infrared LEDs can be utilized in patients with all types of skin pigmentation without concern over safety or excessive tissue heating. Additionally, the doses and device utilized in present study have demonstrated positive outcomes in prior clinical trials. Therefore, it can be concluded that the effects seen by the concurrent use of multiple wavelengths and light sources were the result of desirable photobiomodulation effect and not related to thermal influence.

What is the best treatment to decrease pro-inflammatory cytokine release in acute skeletal muscle injury induced by trauma in rats: low-level laser therapy, diclofenac, or cryotherapy?

Currently, treatment of muscle injuries represents a challenge in clinical practice. In acute phase, the most employed therapies are cryotherapy and nonsteroidal anti-inflammatory drugs. In the last years, low-level laser therapy (LLLT) has becoming a promising therapeutic agent; however, its effects are not fully known. The aim of this study was to analyze the effects of sodium diclofenac (topical application), cryotherapy, and LLLT on pro-inflammatory cytokine levels after a controlled model of muscle injury. For such, we performed a single trauma in tibialis anterior muscle of rats. After 1 h, animals were treated with sodium diclofenac (11.6 mg/g of solution), cryotherapy (20 min), or LLLT (904 nm; superpulsed; 700 Hz; 60 mW mean output power; 1.67 W/cm(2); 1, 3, 6 or 9 J; 17, 50, 100 or 150 s). Assessment of interleukin-1ß and interleukin-6 (IL-1ß and IL-6) and tumor necrosis factor-alpha (TNF-α) levels was performed at 6 h after trauma employing enzyme-linked immunosorbent assay method. LLLT with 1 J dose significantly decreased (p < 0.05) IL-1ß, IL-6, and TNF-α levels compared to non-treated injured group as well as diclofenac and cryotherapy groups. On the other hand, treatment with diclofenac and cryotherapy does not decrease pro-inflammatory cytokine levels compared to the non-treated injured group. Therefore, we can conclude that 904 nm LLLT with 1 J dose has better effects than topical application of diclofenac or cryotherapy in acute inflammatory phase after muscle trauma.

Antimicrobial Activity of Methylene Blue Associated with Photodynamic Therapy: In Vitro Study in Multi-Species Oral Biofilm.

The control of infectious diseases caused by biofilms is a continuing challenge for researchers due to the complexity of their microbial structures and therapeutic implications. Photodynamic therapy as an adjunctive anti-infective treatment has been described as a possible valid approach but has not been tested in polymicrobial biofilm models. This study evaluated the effect of photodynamic therapy in vitro with methylene blue (MB) 0.01% and red LEDs (λ = 660 nm, power density ≈ 330 mW/cm2, 2 mm distance from culture) on the metabolic activity and composition of a multispecies subgingival biofilm. Test Groups LED and MB + LED showed a more significant reduction in metabolic activity than the non-LED application group (~50 and 55%, respectively). Groups LED and MB equally affected (more than 80%) the total bacterial count in biofilms. No differences were noted in the bacterial biofilm composition between the groups. In vitro LED alone or the MB + LED combination reduced the metabolic activity of bacteria in polymicrobial biofilms and the total subgingival biofilm count.

Low-level laser therapy in different stages of rheumatoid arthritis: a histological study.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease of unknown etiology. Treatment of RA is very complex, and in the past years, some studies have investigated the use of low-level laser therapy (LLLT) in treatment of RA. However, it remains unknown if LLLT can modulate early and late stages of RA. With this perspective in mind, we evaluated histological aspects of LLLT effects in different RA progression stages in the knee. It was performed a collagen-induced RA model, and 20 male Wistar rats were divided into 4 experimental groups: a non-injured and non-treated control group, a RA non-treated group, a group treated with LLLT (780 nm, 22 mW, 0.10 W/cm(2), spot area of 0.214 cm(2), 7.7 J/cm(2), 75 s, 1.65 J per point, continuous mode) from 12th hour after collagen-induced RA, and a group treated with LLLT from 7th day after RA induction with same LLLT parameters. LLLT treatments were performed once per day. All animals were sacrificed at the 14th day from RA induction and articular tissue was collected in order to perform histological analyses related to inflammatory process. We observed that LLLT both at early and late RA progression stages significantly improved mononuclear inflammatory cells, exudate protein, medullary hemorrhage, hyperemia, necrosis, distribution of fibrocartilage, and chondroblasts and osteoblasts compared to RA group (p < 0.05). We can conclude that LLLT is able to modulate inflammatory response both in early as well as in late progression stages of RA.

Effect of simvastatin on passive strain-induced skeletal muscle injury in rats.

INTRODUCTION: HMG-CoA reductase inhibitors are the most frequently prescribed drugs for treatment of lipid imbalance, but they have side effects, such as myopathy. Our aim was to assess the effect of simvastatin on the inflammatory process induced by skeletal muscle injury. METHODS: Rats were divided into experimental groups [control group, simvastatin (20 mg/kg) group, group treated with simvastatin (20 mg/kg) and subjected to injury, and group subjected to injury only]. Histological analysis and analyses of creatine kinase activity and C-reactive protein were performed. RESULTS: Animals treated with simvastatin exhibited significantly greater morphological and structural skeletal muscle damage in comparison to the control group and injured animals without treatment. CONCLUSIONS: Although simvastatin has a small anti-inflammatory effect in the early stage after a muscle strain injury, the overall picture is negative, as simvastatin increases the extent of damage to muscle morphology. Further studies are needed.

Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy.

Low-level laser therapy is a tool employed in the management of post-operative inflammation process and in the enhancement of reparative process. The aim of the study was to perform histological evaluation of dental and periodontal ligament of rats central upper-left incisor teeth re-implanted and irradiated with low-level laser (InGaAl, 685 nm, 50 J/cm(2)) 15, 30, and 60 days after re-implantation. Seventy-two male rats had the central upper left incisor removed and kept for 15 min on dry gauze before replantation. Laser was irradiated over the root surface and empty alveolus prior replantation and over surrounding mucosa after the re-implantation. After histological procedures, all slices were analyzed regarding external resorption area and histological aspects. We observed an increase of root resorption (p < 0.05) in the control group compared to the laser group at 15, 30, and 60 days. These results showed that the laser groups developed less root resorption areas than the control group in all experimental periods. Additionally, histological analysis revealed less inflammatory cells and necrotic areas in laser groups.

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

Arthritis of the knee is the most common type of joint inflammatory disorder and it is associated with pain and inflammation of the joint capsule. Few studies address the effects of the 810-nm laser in such conditions. Here we investigated the effects of low-level laser therapy (LLLT; infrared, 810-nm) in experimentally induced rat knee inflammation. Thirty male Wistar rats (230-250 g) were anesthetized and injected with carrageenan by an intra-articular route. After 6 and 12 h, all animals were killed by CO(2) inhalation and the articular cavity was washed for cellular and biochemical analysis. Articular tissue was carefully removed for real-time PCR analysis in order to evaluate COX-1 and COX-2 expression. LLLT was able to significantly inhibit the total number of leukocytes, as well as the myeloperoxidase activity with 1, 3, and 6 J (Joules) of energy. This result was corroborated by cell counting showing the reduction of polymorphonuclear cells at the inflammatory site. Vascular extravasation was significantly inhibited at the higher dose of energy of 10 J. Both COX-1 and 2 gene expression were significantly enhanced by laser irradiation while PGE(2) production was inhibited. Low-level laser therapy operating at 810 nm markedly reduced inflammatory signs of inflammation but increased COX-1 and 2 gene expression. Further studies are necessary to investigate the possible production of antiinflammatory mediators by COX enzymes induced by laser irradiation in knee inflammation.

A systematic review with meta-analysis of the effect of low-level laser therapy (LLLT) in cancer therapy-induced oral mucositis.

PURPOSE: The purpose of this study is to review the effects of low-level laser therapy (LLLT) in the prevention and treatment of cancer therapy-induced oral mucositis (OM). METHODS: A systematic review and meta-analysis of randomised placebo-controlled trials of LLLT performed during chemotherapy or radiation therapy in head and neck cancer patients. RESULTS: We found 11 randomised placebo-controlled trials with a total of 415 patients; methodological quality was acceptable at 4.10 (SD ± 0.74) on the 5-point Jadad scale. The relative risk (RR) for developing OM was significantly (p = 0.02) reduced after LLLT compared with placebo LLLT (RR = 2.03 (95% CI, 1.11 to 3.69)). This preventive effect of LLLT improved to RR = 2.72 (95% CI, 1.98 to 3.74) when only trials with adequate doses above 1 J were included. For treatment of OM ulcers, the number of days with OM grade 2 or worse was significantly reduced after LLLT to 4.38 (95% CI, 3.35 to 5.40) days less than placebo LLLT. Oral mucositis severity was also reduced after LLLT with a standardised mean difference of 1.33 (95% CI, 0.68 to 1.98) over placebo LLLT. All studies registered possible side-effects, but they were not significantly different from placebo LLLT. CONCLUSIONS: There is consistent evidence from small high-quality studies that red and infrared LLLT can partly prevent development of cancer therapy-induced OM. LLLT also significantly reduced pain, severity and duration of symptoms in patients with cancer therapy-induced OM.

In vitro analysis of human tooth pulp chamber temperature after low-intensity laser therapy at different power outputs.

In vitro studies have provided conflicting evidence of temperature changes in the tooth pulp chamber after low-level laser irradiation of the tooth surface. The present study was an in vitro evaluation of temperature increases in the human tooth pulp chamber after diode laser irradiation (GaAlAs, λ = 808 nm) using different power densities. Twelve human teeth (three incisors, three canines, three premolars and three molars) were sectioned in the cervical third of the root and enlarged for the introduction of a thermocouple into the pulp chamber. The teeth were irradiated with 417 mW, 207 mW and 78 mW power outputs for 30 s on the vestibular surface approximately 2 mm from the cervical line of the crown. The highest average increase in temperature (5.6°C) was observed in incisors irradiated with 417 mW. None of the teeth (incisors, canines, premolars or molars) irradiated with 207 mW showed temperature increases higher than 5.5°C that could potentially be harmful to pulp tissue. Teeth irradiated with 78 mW showed lower temperature increases. The study showed that diode laser irradiation with a wavelength of 808 nm at 417 mW power output increased the pulp chamber temperature of certain groups of teeth, especially incisors and premolars, to critical threshold values for the dental pulp (5.5°C). Thus, this study serves as a warning to clinicians that "more" is not necessarily "better".

Comparison between cold water immersion therapy (CWIT) and light emitting diode therapy (LEDT) in short-term skeletal muscle recovery after high-intensity exercise in athletes--preliminary results.

In the last years, phototherapy has becoming a promising tool to improve skeletal muscle recovery after exercise, however, it was not compared with other modalities commonly used with this aim. In the present study we compared the short-term effects of cold water immersion therapy (CWIT) and light emitting diode therapy (LEDT) with placebo LEDT on biochemical markers related to skeletal muscle recovery after high-intensity exercise. A randomized double-blind placebo-controlled crossover trial was performed with six male young futsal athletes. They were treated with CWIT (5°C of temperature [SD ±1°]), active LEDT (69 LEDs with wavelengths 660/850 nm, 10/30 mW of output power, 30 s of irradiation time per point, and 41.7 J of total energy irradiated per point, total of ten points irradiated) or an identical placebo LEDT 5 min after each of three Wingate cycle tests. Pre-exercise, post-exercise, and post-treatment measurements were taken of blood lactate levels, creatine kinase (CK) activity, and C-reactive protein (CRP) levels. There were no significant differences in the work performed during the three Wingate tests (p > 0.05). All biochemical parameters increased from baseline values (p < 0.05) after the three exercise tests, but only active LEDT decreased blood lactate levels (p = 0.0065) and CK activity (p = 0.0044) significantly after treatment. There were no significant differences in CRP values after treatments. We concluded that treating the leg muscles with LEDT 5 min after the Wingate cycle test seemed to inhibit the expected post-exercise increase in blood lactate levels and CK activity. This suggests that LEDT has better potential than 5 min of CWIT for improving short-term post-exercise recovery.

Repair of Critical Size Bone Defects Using Synthetic Hydroxyapatite or Xenograft with or without the Bone Marrow Mononuclear Fraction: A Histomorphometric and Immunohistochemical Study in Rat Calvaria.

Bone defects are a challenging clinical situation, and the development of hydroxyapatite-based biomaterials is a prolific research field that, in addition, can be joined by stem cells and growth factors in order to deal with the problem. This study compares the use of synthetic hydroxyapatite and xenograft, used pure or enriched with bone marrow mononuclear fraction for the regeneration of critical size bone defects in rat calvaria through histomorphometric (Masson's staining) and immunohistochemical (anti-VEGF, anti-osteopontin) analysis. Forty young adult male rats were divided into five groups (n = 8). Animals were submitted to critical size bone defects (Ø = 8 mm) in the temporoparietal region. In the control group, there was no biomaterial placement in the critical bone defects; in group 1, it was filled with synthetic hydroxyapatite; in group 2, it was filled with xenograft; in group 3, it was filled with synthetic hydroxyapatite, enriched with bone marrow mononuclear fraction (BMMF), and in group 4 it was filled with xenograft, enriched with BMMF. After eight weeks, all groups were euthanized, and histological section images were captured and analyzed. Data analysis showed that in groups 1, 2, 3 and 4 (received biomaterials and biomaterials plus BMMF), a significant enhancement in new bone matrix formation was observed in relation to the control group. However, BMMF-enriched groups did not differ from hydroxyapatite-based biomaterials-only groups. Therefore, in this experimental model, BMMF did not enhance hydroxyapatite-based biomaterials' potential to induce bone matrix and related mediators.

Histomorphometric Evaluation of Bone-Guided Regeneration in Maxillary Sinus Floor Augmentation Using Nano-Hydroxyapatite/Beta-Tricalcium Phosphate Composite Biomaterial: A Case Report.

BACKGROUND: The development of techniques in biomaterials design and production added to advanced surgical procedures which enabled better and more predictable clinical outcomes. Maxillary sinus floor augmentation (MSFA) is among the more studied bone-guided regeneration procedure in the literature. The MSFA could be considered the gold standard procedure for bone-guided regeneration as it provides suitable functional and aesthetic solutions to alveolar ridge atrophy due to tooth loss. PURPOSE: This study aimed to conduct a detailed histomorphometric evaluation of collagen production in SFAs bone-guided regeneration, using nano-hydroxyapatite/ß-tricalcium phosphate (nano-HA/ß-TCP) composite. PATIENTS AND METHODS: A 52-year-old female had the left upper second premolar condemned due to periodontal disease, then a tooth implant replacement was planned. Due to maxillary sinus pneumatization, the MSFA had to be done before implant placement. Nano-HA/ß-TCP composite (2g) was used in the MSFA procedure. After nine months of the healing process, during the Cone Morse implant installation process, bone samples were collected for histologic analysis (sirius red, hematoxylin/eosin, polarized microscopy). Six months after implant installation, a ceramic crown was installed according to the patient's request. RESULTS: Proper masticatory function and aesthetics were re-established. The histomorphometric evaluation indicated that nano-HA/ß-TCP composite did not show any area devoid of cellular activity in sirius red or hematoxylin/eosin staining and the percentage (%) of new bone collagen fibers was achieved using polarization technique evaluation. CONCLUSION: According to these results, nano-HA/ß-TCP composite presented clinical and histomorphometric properties suit to be used as bone-guided regeneration biomaterial in MSFA. Furthermore, nano-HA/ß-TCP composite provided a favorable nano-environment to bone cells, enhancing bone matrix production.