It is concluded that, under this experimental condition, LLLT increased bone repair at early bone healing.

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.

It was demonstrated that PDT was efficient at killing microorganisms and preventing the formation of biofilms.

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.

The use of LLLT on chronic wounds in a diabetic foot demonstrated efficacy on the progression of the tissue repair process in a short period.

Thirty Wistar rats (350 +/- 20 g) were subjected to total Achilles tendon tenotomy of the right fore limb. They were submitted to a daily dose of 20 J/cm(2) light emitting diode (LED) (640 +/- 20 nm) therapy. The LED was applied punctually and transcutaneously to the lesioned region. The animals were separated into six groups, C1 and L1, C2 and L2, C3 and L3. The C groups were used for control and the L groups, treated for 7, 14 and 21 consecutive days, respectively. The animals were killed on the 7th, 14th and 21st days after surgery. After the animals had been killed, their tendons were extracted and dissected, fixed in formaldehyde at 10%, and sent for histological analysis by light microscopy in which the repair process was analysed. This study demonstrated that LED interfered in the repair process of the tendon tissue, reducing the number of fibroblasts in the initial periods and improving the quality of the repair in all periods studied.

Objective: The aim of this work was to compare the effect of low-level laser therapy (LLLT) on the wound healing process in nondiabetic and diabetic rats. Background Data: Among the clinical symptoms caused by diabetes mellitus, a delay in wound healing is a potential risk for patients. It is suggested that LLLT can improve wound healing. Methods: The tissue used for this study was extracted from animals suffering from diabetes, which was induced by Streptozotocin ® , and from nondiabetic rats. Animals were assembled into two groups of 25 rats each (treated and control) and further subdivided into two groups: diabetic (n = 15) and nondiabetic (n = 10). A full-thickness skin wound was made on the dorsum area, with a round 8-mm holepunch. The treated group was irradiated by a HeNe laser at 632.8 nm, with the following parameters: 15 mW, exposition time of 17 sec, 0.025 cm 2 irradiated area, and energy density of 10 J/cm 2 . Square full-thickness skin samples (18 mm each side, including both injured and noninjured tissues) were obtained at 4, 7, and 15 days after surgery and analyzed by qualitative and quantitative histological methods. Results: Quantitative histopathological analysis confirmed the results of the qualitative analysis through histological microscope slides. When comparing tissue components (inflammatory cells, vessels and fibroblast/area), we found that treated animals had a less intense inflammatory process than controls. Conclusion: Results obtained by both qualitative and quantitative analyses suggested that irradiation of rats with HeNe (632.8 nm), at the tested dose, promoted efficient wound healing in both nondiabetic and diabetic rats as, compared to the control group. 474

With the aim of accelerating the regenerative processes, the objective was to study the influence of gallium-aluminum-arsenide (GaAlAs) laser (660 nm) on functional and histomorphological recovery of the sciatic nerve in rats. The sciatic nerves of 12 Wistar rats were crushed divided into two groups: control and laser therapy. For the latter, GaAlAs laser was utilized (660 nm, 4 J/cm(2), 26.3 mW and 0.63 cm(2) beam), at three equidistant points on the lesion, for 20 days. Comparison of the sciatic functional index (SFI) showed that there was a significant difference only between the pre-lesion value of the laser therapy group and that after the 21st day in the control group. It was concluded that the parameters and methods utilized demonstrated positive results regarding the SFI over the time period evaluated.