Dose Of Laser Therapy Research Articles

Assessment of a single versus double application of low-level laser therapy in pain reduction following orthodontic elastomeric separation: A randomized controlled trial.

Periodontal ligament (PDL) pain, associated with the insertion of elastomeric separators, is one of the most annoying experiences at the beginning of orthodontic treatment. Low-level laser therapy (LLLT) has recently been suggested as a method of controlling this pain. The aim of this study was to evaluate the effectiveness of LLLT on reducing the pain associated with elastomeric separation and to compare a single dose of LLLT (1 h before the insertion of elastomeric separators) vs 2 doses of LLLT (1 h before and immediately after the insertion). This randomized controlled trial was conducted at the Department of Orthodontics, Faculty of Dentistry of University of Damascus and at the Department of Orthodontics of Adib-Allaham Center in Damascus, Syria. The sample population was comprised of 36 patients, aged between 12 and 25 years (mean age: 17 ±3.7 years), and the patients were randomly divided into 2 groups. A split-mouth design was employed. One group received 1 dose of laser therapy 1 h before the insertion of elastomeric separators, whereas the other one received 2 doses of laser therapy - 1 h before and immediately after the insertion of elastomeric separators. A GaAlAs laser with a wavelength of 830 nm and a power of 100 mW was used. The pain levels were recorded using the Visual Analog Scale (VAS) after 1, 6, 24, 48, and 96 h. Student's t-test and the repeated measures analysis of variance (ANOVA) were employed to detect significant differences. Low-level laser therapy significantly reduced post-separation pain when the experimental side was compared to the placebo side in the single-irradiation group (p < 0.05). Low-level laser therapy significantly reduced separation pain with no statistical difference between single and double irradiation protocols (p > 0.05). Low-level laser therapy had a positive effect on reducing the pain associated with elastomeric separation, whether it was applied as a single dose before elastomeric separation or as a double dose before and after this procedure.

The optimal dose of the Low-level laser therapy in the treatment of type 1 Diabetes Mellitus

Background: Type 1 DM (T1DM) is caused by an autoimmune destruction of pancreatic s cells. We proposed a novel stimulation using a low-level laser therapy (LLLT) through acupuncture points to stimuli the stem cells to be adult pancreatic s cells. This study aimed to identify an optimal dose of low-level laser therapy (LLLT) for treatment of type 1 diabetes mellitus (T1DM). Methods: An experimental study was performed with a pretestposttest control group design. The intervention was tested in rats (Rattus novergicus, Wistar strain). The rats were made diabetic by injection of streptozotocin (STZ). Rats were treated with different doses of LLLT in 4 groups. The tested laser doses were 0.2 joules (group L1), 0.3 joules (group L2), 0.4 joules(group L3), and 0.5 joules (group L4). The therapy was performed by perpendicularly attaching laser probe to the animal body, at the acupuncture point pishu (BL-20) on respective sides. Results: Rats in the L2 group were performing better compared to others. The highest decrease of blood glucose level was found in group L2. Two rats in the L2 group achieved normal blood glucose level upon laser therapy. The dose of laser therapy in the L2 group of 0.3 joules was found to be the optimum dose. Conclusion: Clinical and statistical analyses indicated that 0.3 joule was the optimal dose for LLLT in our animal model. Further investigation of LLLT in human is warranted, and validation of the identified dose in future studies should be pursued.

Limb Blood Flow After Class 4 Laser Therapy

Laser therapy is purported to improve blood flow in soft tissues. Modulating circulation would promote healing by controlling postinjury ischemia, hypoxia, edema, and secondary tissue damage. However, no studies have quantified these responses to laser therapy. To determine a therapeutic dose range for laser therapy for increasing blood flow to the forearm. Crossover study. Controlled laboratory setting. Ten healthy, college-aged men (age = 20.80 ± 2.16 years, height = 177.93 ± 3.38 cm, weight = 73.64 ± 9.10 kg) with no current history of injury to the upper extremity or cardiovascular conditions. A class 4 laser device was used to treat the biceps brachii muscle. Each grid point was treated for 3 to 4 seconds, for a total of 4 minutes. Each participant received 4 doses of laser therapy: sham, 1 W, 3 W, and 6 W. The dependent variables were changes in blood flow, measured using venous occlusion plethysmography. We used a repeated-measures analysis of variance to analyze changes in blood flow for each dose at 2, 3, and 4 minutes and at 1, 2, 3, 4, and 5 minutes after treatment. The Huynh-Feldt test was conducted to examine differences over time. Compared with baseline, blood flow increased over time with the 3-W treatment (F(3,9) = 3.468, P < .011) at minute 4 of treatment (2.417 ± 0.342 versus 2.794 ± 0.351 mL/min per 100 mL tissue, P = .032), and at 1 minute (2.767 ± 0.358 mL/min per 100 mL tissue, P < .01) and 2 minutes (2.657 ± 0.369 mL/min per 100 mL tissue, P = .022) after treatment. The sham, 1-W, and 6-W treatment doses did not change blood flow from baseline at any time point. Laser therapy at the 3-W (360-J) dose level was an effective treatment modality to increase blood flow in the soft tissues.

Laser versus Ultrasound in the Treatment of Supraspinatus Tendinosis : Randomised controlled trial

Summary Thirty-six patients were randomly assigned to three groups to compare the effectiveness of low power laser therapy, ultrasound and no therapy for supraspinatus tendinosis. All three groups were given the same advice and educational material. Measurements were taken before and after treatment for muscle weakness secondary to pain, pain, disability and tenderness. Treatment for the experimental groups comprised nine therapeutic doses over a three-week period of either laser therapy or ultrasound; the control group had no treatment for three weeks. The degree of muscle weakness, pain, functional disability and tenderness for the three groups was similar before treatment. Comparisons after treatment showed that the laser group had less muscle weakness (p < 0.01) and pain (p < 0.01) than the ultrasound and control groups and had less disability (p < 0.05) and tenderness (p < 0.01) after treatment than the control group. These data suggest that the dose of laser therapy used in the study, advice and education improve the symptoms of supraspinatus tendinosis. Ultrasound also improved the symptoms, but was not significantly different from the control group that received advice only. Based on these results laser therapy should be the treatment of choice for supraspinatus tendinosis rather than ultrasound. Thirty-six patients were randomly assigned to three groups to compare the effectiveness of low power laser therapy, ultrasound and no therapy for supraspinatus tendinosis. All three groups were given the same advice and educational material. Measurements were taken before and after treatment for muscle weakness secondary to pain, pain, disability and tenderness. Treatment for the experimental groups comprised nine therapeutic doses over a three-week period of either laser therapy or ultrasound; the control group had no treatment for three weeks. The degree of muscle weakness, pain, functional disability and tenderness for the three groups was similar before treatment. Comparisons after treatment showed that the laser group had less muscle weakness (p < 0.01) and pain (p < 0.01) than the ultrasound and control groups and had less disability (p < 0.05) and tenderness (p < 0.01) after treatment than the control group. These data suggest that the dose of laser therapy used in the study, advice and education improve the symptoms of supraspinatus tendinosis. Ultrasound also improved the symptoms, but was not significantly different from the control group that received advice only. Based on these results laser therapy should be the treatment of choice for supraspinatus tendinosis rather than ultrasound.

Photodynamic therapy of human bladder cancer cells in vitro correlated with cellular fluorescence levels of Photofrin-II.

Abstract In order to determine optimum dose of Photofrin‐II (PHI) timing and dose of laser therapy and differential effects of laser on normal and neoplastic human bladder cancer cells in vitro, experiments were carried out using 3 cell lines of human bladder cancer (253‐J, 639‐V, and 647‐V) and a human fibroblast line (CRL‐1507). Cellular Pf‐II uptake and excretion studied using flow cytometric fluorescence analysis of the cells and fluorescence levels of the culture medium showed a wide variability of uptake of Pf‐II among the cell lines. Pf‐II excretion occurred most rapidly in the first 4 h after incubation reaching maximum at 24‐48 h in all cells studied. Cellular concentration of Pf‐II and supernatant levels of Pf‐II estimated by fluorescence levels had a reciprocal correlation. Laser treatment of one cancer line and the fibroblast line at 20 J (630 nm) at various times after incubation with 50 μ.g m−l of Pf‐II showed that the photodynamic effect correlated directly with cellular fluorescence. These results suggest that in vitro: (1) initial uptake of Pf‐II is generally higher in neoplastic than normal cells but that excretion rates are similar; and (2) photodynamic effect is related primarily to initial cellular levels of photosensitizer rather than differential excretion rates.