scholarly journals Effect of low-level laser (Ga-Al-As 655 nm) on skeletal muscle fatigue induced by electrical stimulation in rats

2006 ◽  
Vol 101 (1) ◽  
pp. 283-288 ◽  
Author(s):  
Rodrigo Álvaro B. Lopes-Martins ◽  
Rodrigo Labat Marcos ◽  
Patrícia Sardinha Leonardo ◽  
Antônio Carlos Prianti ◽  
Marcelo Nicolas Muscará ◽  
...  

We investigated whether low-level laser therapy (LLLT) can reduce muscular fatigue during tetanic contractions in rats. Thirty-two male Wistar rats were divided into four groups receiving either one of three different LLLT doses (0.5, 1.0, and 2.5 J/cm2) or a no-treatment control group. Electrical stimulation was used to induce six tetanic muscle contractions in the tibial anterior muscle. Contractions were stopped when the muscle force fell to 50% of the initial value for each contraction (T50%). There was no significant difference between the 2.5 J/cm2 laser-irradiated group and the control group in mean T50% values. Laser-irradiated groups (0.5 and 1.0 J/cm2) had significantly longer T50% values than the control group. The relative peak force for the sixth contraction in the laser-irradiated groups were significantly higher at 92.2% (SD 12.6) for 0.5 J/cm2, 83.2% (SD 20.5) for 1.0 J/cm2, and 82.9% (SD 18.3) for 2.5 J/cm2 than for the control group [50% (SD 15)]. Laser groups receiving 0.5 and 1.0 J/cm2 showed significant increases in mean performed work compared with both the control group and their first contraction values. Muscle damage was indirectly measured by creatine kinase levels in plasma. A distinct dose-response pattern was found in which 1.0 and 2.5 J/cm2 LLLT groups had significantly lower creatine kinase levels than the 0.5 J/cm2 LLLT group and the control group. We conclude that LLLT doses of 0.5 and 1.0 J/cm2 can prevent development of muscular fatigue in rats during repeated tetanic contractions.

2021 ◽  
Vol 19 (2) ◽  
pp. 111-115
Author(s):  
Estéfani Marin ◽  
◽  
Jacqueline Lumy Fuse ◽  
Larissa Pereira Lopes ◽  
Morgana Neves ◽  
...  

Introduction. Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune inflammatory disease of unknown origin, mainly affecting synovial joints and related structures, including the adjacent musculature, generating great disability and reduction in quality of life. Aim. This study was designed to investigate the effect of low-level laser therapy (LLLT) on gastrocnemius of Wistar rats subjected to an experimental model of RA. Material and methods. Forty male Wistar rats were used, separated into: acute and chronic, being subdivided into Control Group (CG): without intervention, Lesion Group (LG): submitted to lesion, Laser Control Group (LCG): without lesion and with treatment, and Laser Lesion Group (LLG): submitted to lesion and LLLT. The treatment with LLLT occurred in four points of the right knee, wavelength of 660 nm, energy density of 5 J/cm2, energy per point of 0.003 J. Morphometric analysis was performed using a 40x magnification photomicrograph and analyzed using the Image-Pro-Plus 6.0 program. Results. As result of the acute group there was a difference only for muscle mass, being higher in CG. For the chronic group there was significant difference for cross-sectional area, larger and smaller diameter, again with the control group obtaining higher values than the others, for the number of nuclei LG was lower than CG and LCG, but LLG was not different from any of them. Conclusion. It is concluded that treatment with LLLT was not very effective in reversing the harmful effects of RA on the gastrocnemius muscle.


2020 ◽  
Vol 11 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Maryam Baghizadeh Fini ◽  
Pooya Olyaee ◽  
Ahmadreza Homayouni

In clinical practice, low-level laser therapy (LLLT) is widely used. The main aim of this review is to assess the effectiveness of LLLT in accelerating tooth movement in human subjects. The PRISMA checklist was utilized as a guideline to carry out this systematic review. The electronic databases were searched from Google Scholar (2014-2018) and PubMed, and comprehensive research on this topic was also manually conducted. Therefore, 77 articles randomized clinical trials (RCTs) or controlled clinical trials (CCTs) were selected. After screening studies, consequently, eleven trials met the inclusion criteria. Eight out of 11 studies showed LLLT has a significant impact on the acceleration of orthodontic tooth movement, and there was no statistically significant difference in the rate of tooth movement between the laser group and the control group in the two remaining studies. Furthermore, five out of 11 articles showed that LLLT has no adverse effects. Although we have some degree of understanding from a cellular point of view to LLLT effects, we still do not know whether these cellular level changes have any effect on the clinical acceleration of orthodontic tooth movement. The results are inconclusive and cannot be generalized to the public community; therefore, well-structured studies are required.


2016 ◽  
Vol 4 (4) ◽  
pp. 720-725 ◽  
Author(s):  
Ahmed Abbas Zaky ◽  
Hanaa M. Elshenawy ◽  
Tarek Abdel Hamed Harhash ◽  
Mahmoud Shalash ◽  
Noha Ismael Awad

AIM: The aim of the study was to evaluate the effect of Low-Level Laser Therapy (LLLT) on bone formation in cystic defects following cyst enucleation.PATIENTS AND METHODS: The sample was composed of sixteen patients with enucleated maxillary bony cystic lesions. With an age range from 20 - 44 grouped as eight Laser and eight Control patients. Laser group was subjected to low intensity diode laser immediately after surgery and then for three times per week for two weeks using a therapeutic laser irradiation. Group B (control group): patients were not subjected laser therapy.RESULTS: The predictor variable was exposure of bone defect to LLLT or none. The outcome variable was bone density changes measured by digital radiographs at day 1 and days 90 postoperatively. Descriptive and bivariate statistics were computed. There were no statistically significant differences between the 2 groups for the bone density at day 1. There was a statistically significant difference in bone density changes in each group at day 90: Significant at P ≤ 0.05. After adjusting for differences in day 1 for bone density, the estimated mean change in bone density changes at day 90 was significantly larger for Laser compared with control.CONCLUSION: The results of this study suggested that LLLT can enhance bone healing in maxillary cystic defects. This can serve as an adjunct method in preventing possible delayed healing and pathological fractures This also will be helpful for more researchers in early loading in case of dental implants to accelerate osseointegration.


Author(s):  
VARSHA PALLED ◽  
DR. JITENDRA RAO ◽  
DR. RAGHUWAR DAYAL SINGH ◽  
DR. SHUCHI TRIPATHI ◽  
DR. KALPANA SINGH ◽  
...  

The purpose of this study was to evaluate whether Low-Level Laser Therapy (LLLT) improves the healing of the implant surgical site with clinical and biochemical parameters.Thirty patients with an edentulous space spanning a single tooth were selected. The patients were randomly allocated to two groups - the control group and the test group. The test group received laser energy at a power of 2J/cm 2 with a total of 4-6J energy over each implant. Clinical parameters (Implant Stability Quotient, probing index, modified sulcus bleeding index)and osteoprotegerin (OPG) were assessed at baseline and follow-up intervals (2 weeks, 6 weeks, and 3 months).The test group showed significantly higher implant stability quotient compared to thecontrol group at 2 weeks(57.93±3.95 and 35.67±3.08; p<0.01) and 3months(58.86±3.75 and 67.06±3.78; p<0.01). A significant rise in OPG levels of the test group(686.30±125.36pg/ml at baseline and 784.25±108.30pg/ml at 3months;p<0.01) was seen contrary to significant decline in the control group (839.50±249.08pg/ml at baseline,415.30±78.39pg/ml at 3months;p<0.01). Within the limitations of the study, the study suggests that the healing of peri-implant hard and soft tissues may be enhanced with the use of LLLT as an explicit modality during the post-operative period.


2014 ◽  
Vol 2 (5) ◽  
pp. 376
Author(s):  
Priscila Leite ◽  
Nicole Melo ◽  
Pâmela Silva ◽  
Robinsom Montenegro ◽  
Paulo Bonan ◽  
...  

AIM: Conducting a systematic review of randomized clinical trials focusing on the efficacy of LLLT on pain control in patients with TMD, diagnosed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). MATERIAL AND METHODS: Search was performed at PubMed/MEDLINE database with the terms: (1) “Laser AND temporomandibular disorders”; (2) “Laser AND temporomandibular disorders AND RDC/TMD”; (3) “Low-level laser therapy AND temporomandibular disorders”; (4) “Low-level laser therapy AND temporomandibular disorders AND RDC/TMD”; (5) “Low-level laser therapy AND temporomandibular joint dysfuntion syndrome”; (6) “Low-level laser therapy AND temporomandibular joint dysfuntion syndrome AND RDC/TMD”; (7) “Laser AND temporomandibular joint dysfuntion syndrome” (8) “Laser AND RDC/TMD”; (9) “Low-level laser therapy AND RDC/TMD”. Inclusion criteria: articles need to be randomized clinical trial performed in humans; evaluate the effect of LLLT in the treatment of TMD diagnosed by the use of RDC/TMD; published in English or Portuguese in the last 10 years. Protocol studies and pilot studies were excluded. RESULTS: Ten studies were included. The type of laser used was Gallium Aluminum Arsenide (GaAlAs) diode, with exception of 1 paper, which used super pulsed Gallium Arsenide laser. Eight studies reported decreased in pain levels, in two articles there was no statistically significant difference between test and placebo groups. CONCLUSION: In most studies, LLLT was effective in pain remission, but there is no standardization in parameters like wavelength, output power and frequency. Studies with more complex experimental designs, standardized diagnostic criteria for TMD and defined protocols for the use of LLLT are needed to determine its efficacy in the treatment of TMD.


2016 ◽  
Vol 25 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Andrew T. Doyle ◽  
Christine Lauber ◽  
Kendra Sabine

Clinical Scenario:Tendinopathies plague many active individuals, causing pain and reducing sport activity by decreasing range of motion and strength. There are many modalities that have been used to treat pain associated with chronic inflammation, such as ultrasound, moist heat packs, and electrical stimulation. Low-level laser therapy (LLLT) is one such modality. Potential benefits of managing pain associated with tendinopathies have been investigated using LLLT. Cellular respiration and metabolism are thought to be increased by LLLT acting on the mitochondrial cytochromes. The effects LLLT may have on cellular activity could increase blood flow to progress the healing process by reducing the pain-spasm cycle. The purpose of this critically appraised topic is to identify the clinical effectiveness of LLLT on pain associated with tendinopathy and to identify the parameters used to achieve statistically and clinically relevant pain outcomes.Focused Clinical Question:What is the effect of LLLT on pain associated with tendinopathy?Clinical Bottom Line:Although LLLT significantly decreases pain from baseline, its use may be no better than placebo or traditional treatments such as ultrasound, moist heat packs, electrical stimulation, or therapeutic exercise to reduce pain associated with tendinopathy. Total accumulated joules across the treatment sessions may need to be taken into account as a parameter.


2009 ◽  
Vol 25 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Daniela Aparecida Sussai ◽  
Paulo de Tarso Camillo de Carvalho ◽  
Doroty Mesquita Dourado ◽  
Ana Carulina Guimarães Belchior ◽  
Filipe Abdalla dos Reis ◽  
...  

2018 ◽  
Vol 8 (6) ◽  
pp. 130-137
Author(s):  
Huong Nguyen Thi Mai ◽  
Tai Tran Tan ◽  
Khanh Hong Quoc

Background: The most frequently performed surgical procedure in dentistry is impacted third molar extraction with difficulty varies according to the location of the tooth. Laser therapy after surgery can accelerate cell and tissue reconstruction along with relieve post-operative pain. The objective of this study was to investigate the clinical and radiographic characteristics of impacted lower third molar and to evaluate the results of surgical extraction of impacted lower third molar with post-surgical low-level laser therapy (LLLT). Subjects and Methods: Clinical and radiographic data from 90 patients (average age 28.13 ± 5.38) subjected to a surgical extraction of lower third molar were pooled and divided randomly into 3 groups: group 1 received LLLT immediately after surgery intraorally, group 2 treated with LLLT immediately after the extraction extraorally. Patients received routine management with nonactivated laser were inserted in the control group. Assessments of pain, swelling and trismus level were carried out at 24, 48 hours and on the 7th day after surgery. Results: Correlation of wisdom teeth to ramus and adjacent teeth mainly type II (88.9%), type III accounted for 11.1%. Relative depth of wisdom teeth in the bone mainly position B (81.1%), position C (18.9%). Correlation of wisdom teeth axis to adjacent teeth: horizontal (58.9%), mesioangular impactions (40%) and distoangular impaction (1.1%). There were statistically significant decreases in the level of pain, edema and interincisal opening between the laser-treated groups and the control group on the 1st and 2nd postoperative day. Conclusions: Intraoral and extraoral post-surgical low-level laser therapy treatment was useful in reducing swelling, pain and trismus compared to placebo group in impacted third molar surgery. Key words: Impacted lower third molar, low- level laser therapy


2020 ◽  
Vol 46 (5) ◽  
pp. 526-531 ◽  
Author(s):  
Fawaz Alqahtani ◽  
Nasser Alqhtani ◽  
Sree Lalita Celur ◽  
Darshan Devang Divakar ◽  
Abdulaziz A. Al-Kheraif ◽  
...  

We hypothesized that in the long term (6-month follow-up), nonsurgical mechanical debridement (NSMD) with adjunct low-level laser therapy (LLLT) is more effective for the treatment of peri-implantitis than NSMD alone. The aim of the present 6-month follow-up convenience-sample cohort study was to assess the efficacy of LLLT as an adjunct to NSMD in the treatment of peri-implantitis. A questionnaire was used to collect demographic information. Patients with peri-implantitis in the test and control groups underwent NSMD with and without adjunct LLLT, respectively. Randomization was done by tossing a coin. In the test group, the laser was applied perpendicular to the periodontal pocket for 20 seconds at a constant distance of 15 mm and with a continuous wavelength (3.41 J/cm2 delivery with a 1.76 cm2 spot and average output of 0.3 W). In both groups, peri-implant probing depth, bleeding upon probing, and crestal bone resorption were assessed at baseline and at the 3-month and 6-month follow-up. Group comparisons were performed, and P < .05 was considered statistically significant. Sixty-seven individuals with peri-implantitis were included. The mean age of participants who underwent NSMD with adjunct LLLT and NSMD alone was 46.5 ± 3.4 and 45.3 ± 1.1 years, respectively. At the 3- and 6-month follow-up, peri-implant (P < .05), bleeding upon probing (P < .05), and probing depth (P < .05) were significantly higher among patients who underwent NSMD alone compared with patients who underwent NSMD with adjunct LLLT. There was no significant difference in crestal bone resorption in all patients up to the 6-month follow-up. In the short term, NSMD with adjunct LLLT was a useful treatment protocol for the treatment of peri-implant soft-tissue inflammation.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hasibe Baser Keklikci ◽  
Ahmet Yagci ◽  
Arzu Hanim Yay ◽  
Ozge Goktepe

Abstract Background Investigating the effects of 405-nm, 532-nm, 650-nm, and 950-nm wavelengths of LLLTs (low-level laser therapies) on the orthodontic tooth movement in rats by using histological and immunohistochemical methods. Forty-five Wistar albino rats were randomly divided into 5 groups: control group (positive control: the left maxillary 1st molar side; negative control: the right maxillary 1st molar side), 405 nm LLLT group (Realpoo), 532 nm LLLT group (Realpoo), 650 nm LLLT group (Realpoo), and 940 nm LLLT group (Biolase). The left maxillary 1st molar teeth of all rats were applied mesially 50-g force. Starting from the 1st day, 48 h intervals, LLLT was applied in continuous wave mode and in contact with the tissue. The application area was approximately 1 cm2. The lasers were performed for 3 min on each surface (buccal, palatal, mesial), totally 9 min (total dose 54 J/cm2). The amount of the molar mesialization, the bone area between the roots, PDL (periodontal ligament) measurements, TRAP (tartrate-resistant acid phosphatase), and ALP (alkaline phosphatase) immunoreactivity intensity were calculated. Results The amount of the molar mesialization was significantly higher in the 650 nm LLLT group (mean 0.878 ± 0.201 mm; 95% CI (confidence interval) 0.724 and 1.032) than in the groups of positive control (mean 0.467 ± 0.357 mm; 95% CI 0.192 and 0.741) and 405 nm LLLT (mean 0.644 ± 0.261 mm; 95% CI 0.443 and 0.845) (p < 0.001). There were significant differences in the PDL-mesial (p = 0.042) and PDL-distal (p = 0.007) regions between the groups. The immunoreactivity intensity for TRAP-mesial was significantly higher in the positive control group (mean 109,420.33 ± 8769.17; 95% CI 100,217.65 and 118,623.02) than in the 405 nm (mean 91,678.83 ± 7313.39; 95% CI 84,003.9 and 99,353.77) and the 650 nm LLLT (mean 87,169.17 ± 4934.65; 95% CI 81,990.56 and 92,347.77) groups (p = 0.002). There was no statistically significant difference between the groups on immunoreactivity intensity with ALP staining. Conclusions The results of this study show that LLLT with 650-nm wavelength increases orthodontic tooth movement more than 405-nm, 532-nm, and 940-nm LLLTs. The 940-nm and 650-nm LLLTs also increase the bone area between the roots by more than 405-nm and 532-nm wavelengths.


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