Low Level Laser Therapy LLLT / Cold Laser Literature watch for Feb 2012

Just 9 papers for you this month including LLLT for orthodontic tooth movement, diabetic periodontitis, ischemic stroke and a laboratory study on chronic mild stress to add to the clinical reports we have seen in recent months.

A plug for the 2012 World Association for Laser Therapy conference in Gold Coast Australia in September. You know you have to go to Australia at some time in your life, well this is that time. Not only does Australia have the most extraordinary wilderness, wildlife and waves of anywhere in the world, it is also the host of this year’s WALT conference. I anticipate that most of the researchers you have read about on this newsletter / blog over recent years will be there . At the WALT 2012 conference in September you can see their latest work and hear their latest thoughts first hand. This land of sun, sea and and so many lasers is probably the most welcoming country i have ever visited, so I suggest you click here to register and click here to book your flights.

Effect of low-level laser therapy (LLLT) on orthodontic tooth movement.

Genc G, Kocadereli I, Tasar F, Kilinc K, El S, Sarkarati B

Eskisehir, Turkey.

The aim of this study is to evaluate the effects of low-level laser therapy (LLLT) on (1) the velocity of orthodontic tooth movement and (2) the nitric oxide levels in gingival crevicular fluid (GCF) during orthodontic treatment. The sample consisted of 20 patients (14 girls, six boys) whose maxillary first premolars were extracted and canines distalized. A gallium-aluminum-arsenide (Ga-Al-As) diode laser was applied on the day 0, and the 3rd, 7th, 14th, 21st, and 28th days when the retraction of the maxillary lateral incisors was initiated. The right maxillary lateral incisors composed the study group (the laser group), whereas the left maxillary lateral incisors served as the control. The teeth in the laser group received a total of ten doses of laser application: five doses from the buccal and five doses from the palatal side (two cervical, one middle, two apical) with an output power of 20 mW and a dose of 0.71 J /cm(2). Gingival crevicular fluid samples were obtained on the above-mentioned days, and the nitric oxide levels were analyzed. Bonferroni and repeated measures variant analysis tests were used for statistical analysis with the significance level set at p ≤ 0.05. The application of low-level laser therapy accelerated orthodontic tooth movement significantly; there were no statistically significant changes in the nitric oxide levels of the gingival crevicular fluid during orthodontic treatment.

Lasers Med Sci 2012 Feb 18

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22350425

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A histological evaluation of a low-level laser therapy as an adjunct to periodontal therapy in patients with diabetes mellitus.

Obradovic R, Kesic L, Mihailovic D, Antic S, Jovanovic G, Petrovic A, Pesevska S

Department of Periodontology and Oral Medicine, Faculty of Medicine, University of Nis, 45/19 Nikola Tesla Blvd, 18000, Nis, Serbia, dr.rada@yahoo.com.

Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.

Lasers Med Sci 2012 Feb 5

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22311659

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Transcranial laser therapy for acute ischemic stroke: a pooled analysis of NEST-1 and NEST-2.

Department of Neurology, University of New Mexico, Albuquerque, NM, USA.

BACKGROUND: NeuroThera Effectiveness and Safety Trials (NEST) 1 and 2 have demonstrated safety of transcranial laser therapy (TLT) for human treatment in acute ischemic stroke. NEST 1 study suggested efficacy of TLT but the following NEST 2, despite strong signals, missed reaching significance on its primary efficacy endpoint. In order to assess efficacy in a larger cohort, a pooled analysis was therefore performed. METHODS: The two studies were first compared for heterogeneity, and then a pooled analysis was performed to assess overall safety and efficacy, and examined particular subgroups. The primary endpoint for the pooled analysis was dichotomized modified Rankin scale (mRS) 0-2 at 90 days. RESULTS: Efficacy analysis for the intention-to-treat population was based on a total of 778 patients. Baseline characteristics and prognostic factors were balanced between the two groups. The TLT group (n = 410) success rate measured by the dichotomized 90-day mRS was significantly higher compared with the sham group (n = 368) (P = 0.003, OR: 1.67, 95% CI: 1.19-2.35). The distribution of scores on the 90-day mRS was significantly different in TLT compared with sham (P = 0.0005 Cochran-Mantel-Haenszel). Subgroup analysis identified moderate strokes as a predictor of better treatment response. CONCLUSIONS: This pooled analysis support the likelihood that transcranial laser therapy is effective for the treatment of acute ischemic stroke when initiated within 24 h of stroke onset. If ultimately confirmed, transcranial laser therapy will change management and improve outcomes of far more patients with acute ischemic stroke.

Int J Stroke 2012 Feb 2

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22299818

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[Pain and discomfort in orthodontic treatments. Literature review].

Koritsanszky N, Madlena M

Semmelweis Egyetem Fogorvostudomanyi Kar Gyermekfogaszati gs Fogszabalyozasi Klinika, Budapest.

The experience of pain and discomfort during orthodontic treatment is common. Pain is a subjective response to noxious stimuli, but it is also influenced by age, gender, previous pain experience, emotional factors and stress. The ortodontic treatments such as separation, placement of the arch wire, activation of the fix or removable appliances and debonding cause some degree of pain for the patient. In a prospective study 95% of the patients reported pain experience during orthodontic treatment. The periodontal pain caused by the combination of pressure, ischemia, inflammation and oedema. The pain starts within 4 hours, increases over the next 24 hours, and decrease within 7 days, so it may not be identified by the orthodontist at recall visit. The most common method to measure the intensity of the pain is the NRS (numerical rating scale), where patients can rate their pain intensity from 1 to 10 or 1 to 100. There are many modalities to control orthodontic pain, we can use different analgesic agents, solf-laser irradiation, transcutaneous electrical nerve stimulation and hypnotherapy. The aim of this review to provide an overview on discomfort and pain reaction during orthodontic treatments and discussion of the possible measurement and alleviation of pain.

Fogorv Sz 2011 Dec 104(4) 117-21

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22308951

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Pulsed light irradiation improves behavioral outcome in a rat model of chronic mild stress.

Wu X, Alberico SL, Moges H, De Taboada L, Tedford CE, Anders JJ

Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814.

BACKGROUND AND OBJECTIVE: Transcranial laser therapy (TLT) has been used successfully for the treatment of stroke in animal models and clinical trials. These results support the hypothesis that TLT could be used to treat other central nervous system conditions, such as depression. Current therapy for depression emphasizes pharmaco-therapeutics. However, these interventions often cause unwanted side effects. Here, TLT as a treatment for depression was studied in a rat model of chronic mild stress (CMS). STUDY DESIGN/MATERIAL AND METHODS: Wistar rats were randomized into four experimental groups (n = 8): (1) No-stress; (2) stress without treatment (Stress); (3) stress treated with an antidepressant (Drug); and (4) stress treated with TLT (TLT). The rats in the stress groups were exposed sequentially to a variety of mild stressors for 8 weeks. Rats were weighed weekly. After 5 weeks of stressing, the Drug group received a daily injection of fluoxetine (10 mg/kg), and the TLT group was irradiated transcranially 3 times a week (810 nm wavelength laser, 3 mm diameter probe, 350 mW peak power, 100 Hz with 20% duty cycle, 2-minute treatment time, 120 J/cm(2) average energy density on skin surface). After 3 weeks of treatment, a forced swimming test (FST) was performed and recorded for behavioral assessment. Animals were euthanized after 8 weeks of the study. RESULTS: The No-stress group had significantly higher body weight than stress groups from week 5 (P < 0.05). No weight difference was found between the stress groups before treatment. However, the Drug group had significantly less body weight than both Stress and TLT groups after 2 weeks of treatment (P < 0.05). FST showed that the Stress group had significantly more immobility than the No-stress group (P < 0.05). Both Drug and TLT groups had significantly less immobility than the stress group (P < 0.05). There was no significant difference in immobility between both Drug and TLT groups (P = 0.62). CONCLUSIONS: TLT was comparable to fluoxetine in improving the behavioral outcome after CMS. TLT did not cause weight loss, which is consistently seen in patients treated with fluoxetine. This study demonstrates that TLT has potential as an effective treatment for depression. Lasers Surg. Med. (c) 2012 Wiley Periodicals, Inc.

Lasers Surg Med 2012 Feb 14

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22334326

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Low-power laser irradiation (LPLI) promotes VEGF expression and vascular endothelial cell proliferation through the activation of ERK/Sp1 pathway.

Feng J, Zhang Y, Xing D

Angiogenesis, the growth of new blood vessels from pre-existing vessels, represents an excellent therapeutic target for the treatment of wound healing and cardiovascular disease. Herein, we report that LPLI (low-power laser irradiation) activates ERK/Sp1 (extracellular signal-regulated kinase/specificity protein 1) pathway to promote VEGF expression and vascular endothelial cell proliferation. We demonstrate for the first time that LPLI enhances DNA-binding and transactivation activity of Sp1 on VEGF promoter in vascular endothelial cells. Moreover, Sp1-regulated transcription is in an ERK-dependent manner. Activated ERK by LPLI translocates from cytoplasm to nuclear and leads to increasing interaction with Sp1, triggering a progressive phosphorylation of Sp1 on Thr453 and Thr739, resulting in the upregulation of VEGF expression. Furthermore, selective inhibition of Sp1 by mithramycin-A or shRNA suppresses the promotion effect of LPLI on cell cycle progression and proliferation, which is also significantly abolished by inhibition of ERK activity. These findings highlight the important roles of ERK/Sp1 pathway in angiogenesis, supplying potential strategy for angiogenesis-related diseases with LPLI treatment.

Cell Signal 2012 Feb 2

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22326662

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Time-dependent effects of low-level laser therapy on the morphology and oxidative response in the skin wound healing in rats.

Goncalves RV, Novaes RD, do Carmo Cupertino M, Moraes B, Leite JP, do Carmo Gouveia Peluzio M, de Mello Pinto MV, da Matta SL

Department of Morphology, Federal University of Pelotas, Pelotas, RS, Brazil.

This study aims to investigate the effect of different energy densities provided by low-level laser therapy (LLLT) on the morphology of scar tissue and the oxidative response in the healing of secondary intention skin wounds in rats. Twenty-four male adult Wistar rats were used. Skin wounds were made on the backs of the animals, which were randomized into three groups of eight animals each as follows, 0.9% saline (control); laser GaAsAl 30 J/cm(2) (L30); laser GaAsAl 90 J/cm(2) (L90). The experiment lasted 21 days. Every 7 days, the wound contraction index (WCI) was calculated and tissue from different wounds was removed to assess the proportion of cells and blood vessels, collagen maturation index (CMI), thiobarbituric acid reactive substance (TBARS) levels and catalase activity (CAT). On the 7th and 14th days, the WCI and the proportion of cells were significantly higher in groups L30 and L90 compared to the control (p < 0.05). At all the time points analyzed, there was a greater proportion of blood vessels and a higher CMI in group L90 compared to the other groups (p < 0.05). On the 7th and 14th days, lower TBARS levels and increased CAT activity were found in the L90 group compared to the control (p < 0.05). On the 7th day, a moderately negative correlation was found between TBARS levels and WCI, CMI and CAT in all the groups. LLLT may modulate the oxidative status of wounded tissue, constituting a possible mechanism through which the LLLT exerts its effects in the initial phases of tissue repair.

Lasers Med Sci 2012 Feb 22

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22354548

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Low-level laser therapy alleviates neuropathic pain and promotes function recovery in rats with chronic constriction injury-possible involvements in hypoxia-inducible factor 1alpha (HIF-1alpha).

Hsieh YL, Chou LW, Chang PL, Yang CC, Kao MJ, Hong CZ

Department of Physical Therapy, Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan 40402. sherrie@mail.cmu.edu.tw.

Nerve inflammation plays an important role in the development and progression of neuropathic pain after chronic constrictive injury (CCI). Recent studies have indicated that hypoxia-inducible factor 1alpha (HIF-1alpha) is crucial in inflammation. Low-level laser therapy has been used in treating musculoskeletal pain, but rare data directly support its use for neuropathic pain. We investigated the effects of low-level laser on the accumulation of HIF-1alpha, tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) in controlling neuropathic pain, as well as on the activation of vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) in promoting functional recovery in a rat CCI model. CCI was induced by placing four loose ligatures around the sciatic nerve of rats. Treatments of low-level laser (660 nm, 9 J/cm(2) ) or sham irradiation (0 J/cm(2) ) were performed at the CCI sites for seven consecutive days. The effects of laser in animals with CCI were determined by measuring the mechanical paw withdrawal threshold, as well as the sciatic, tibial, and peroneal function indices. Histopathological and immunoassay analyses were also performed.Low-level laser therapy significantly improved paw withdrawal threshold, and the sciatic, tibial, and peroneal functional indices after CCI. The therapy also significantly reduced the overexpressions of HIF-1alpha, TNF-alpha, and IL-1beta, and increased the amounts of VEGF, NGF, and S100 proteins. In conclusion, a low-level laser could modulate HIF-1alpha activity. Moreover, it may also be used as a novel and clinically applicable therapeutic approach for the improvement of tissue hypoxia/ischemia and inflammation in nerve entrapment neuropathy, as well as for the promotion of nerve regeneration. These findings might lead to a sufficient morphological and functional recovery of the peripheral nerve. J. Comp. Neurol., 2012. (c) 2012 Wiley Periodicals, Inc.

J Comp Neurol 2012 Feb 20

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22351621

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Effect of laser phototherapy on the hyalinization following orthodontic tooth movement in rats.

Habib FA, Gama SK, Ramalho LM, Cangussu MC, Dos Santos Neto FP, Lacerda JA, de Araujo TM, Pinheiro AL

1 Centro de Ortodontia e Ortopedia Facial Prof. Jose Edimo Soares Martins, School of Dentistry, Federal University of Bahia (UFBA) , Salvador, BA, Brazil .

Abstract Objective: We aimed to assess histologic changes after the use of laser phototherapy (LPT) during induced tooth movement with 40 g/F on young adult male rats. Background data: Hyalinization is a sterile necrosis at the pressure zone of the periodontal ligament observed during the initial stages of the orthodontic movement, and extensive hyaline areas might cause an important delay in the tooth movement. The use of LPT is considered an enhancement factor for bone repair, as it stimulates microcirculation as well as the cellular metabolism. Materials and methods: Thirty animals were divided into two groups (n=15), named according to the time of animal death (7, 13, and 19 days). Half of the animals in each group were subjected to irradiation with infrared (IR) laser (lambda790 nm, round shaped beam, 40 mW, continuous wave (CW), diameter=2 mm (0.0314 cm(2)), 1.273 W/cm(2), time=2×112 sec+1×275 sec (total time 499 sec), 2×142.6/4.48 J+1×350/11 J, 635.2 J/cm(2)/20 J/ session), during orthodontic movement, the other half were used as nonirradiated controls. After animal death, specimens were sectioned, processed, and stained with hematoxylin and eosin (HE) and Sirius Red, and were used for semi-quantitative histologic analysis by light microscopy. Data were statistically analyzed. Results: We demonstrated that LPT positively affected an important aspect of dental movement; the hyalinization. In the present study, we found a significant reduced expression of hyalinization after 19 days. On irradiated subjects, hyalinization was increased at day 7 with significant reduction at day 13. Conclusions: It is possible to conclude that the use of laser light caused histologic alterations during the orthodontic movement characterized by increased formation of areas of hyalinization at early stages, and late reduction when compared to nonirradiated animals.

Photomed Laser Surg 2012 Mar 30(3) 179-85

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22321059

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Biostimulatory effect of low-level laser therapy on keratinocytes in vitro.

Basso FG, Oliveira CF, Kurachi C, Hebling J, Costa CA

Piracicaba School of Dentistry, UNICAMP – University of Campinas, Piracicaba, SP, 13414-903, Brazil.

Epithelial cells play an important role in reparative events. Therefore, therapies that can stimulate the proliferation and metabolism of these cells could accelerate the healing process. To evaluate the effects of low-level laser therapy (LLLT), human keratinocytes were irradiated with an InGaAsP diode laser prototype (LASERTable; 780 +/- 3 nm; 40 mW) using 0.5, 1.5, 3, 5, and 7 J/cm(2) energy doses. Irradiations were done every 24 h totaling three applications. Evaluation of cell metabolism (MTT assay) showed that LLLT with all energy doses promoted an increase of cell metabolism, being more effective for 0.5, 1.5, and 3 J/cm(2). The highest cell counts (Trypan blue assay) were observed with 0.5, 3, and 5 J/cm(2). No statistically significant difference for total protein (TP) production was observed and cell morphology analysis by scanning electron microscopy revealed that LLLT did not promote morphological alterations on the keratinocytes. Real-time polymerase chain reaction (qPCR) revealed that LLLT also promoted an increase of type I collagen (Col-I) and vascular endothelial growth factor (VEGF) gene expression, especially for 1.5 J/cm(2), but no change on fibroblast growth factor-2 (FGF-2) expression was observed. LLLT at energy doses ranging from 0.5 to 3 J/cm(2) promoted the most significant biostimulatory effects on cultured keratinocytes.

Lasers Med Sci 2012 Feb 8

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22314560

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About James Carroll

Founder and CEO at THOR Photomedicine Ltd. About THOR
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