Carolina Montagn Carvalho

Influence of the Use of Laser Phototherapy (λ660 or 790 nm) on the Survival of Cutaneous Flaps on Diabetic Rats

OBJECTIVE The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats. BACKGROUND Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models. ANIMALS AND METHODS Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis. RESULTS It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04). CONCLUSION LPT was effective in increasing angiogenesis as seen on irradiated subjects and was more pronounced when IR laser light was used.

The Use of Light Photobiomodulation on the Treatment of Second-Degree Burns: A Histological Study of a Rodent Model

OBJECTIVE The aim of this investigation was to compare, by light microscopy, the effects of the use of laser photobiomodulation (LPBM) and polarized light (PL) on second-degree burns on rodents. BACKGROUND DATA Burns are severe injuries that result in the loss of tissue fluids, destruction of tissues, infection, and shock. With severe and widespread third-degree burns death may occur. Several light sources have been suggested as being effective for improving wound healing. MATERIALS AND METHODS Forty five rats were used in this study. A second-degree burn was created on the dorsum of each animal, and the animals were divided into four groups: PL (400-2000 nm, 40 mW, 2.4 J/cm(2)/min); LPBM-1 (780 nm, 35/40 mW, theta approximately 2 mm, 4 x 5 J/cm(2)); LPBM-2 (660 nm, 35/40 mW, theta approximately 2 mm, 4 x 5 J/cm(2)); and untreated animals acted as controls. The treatment was started immediately post-burn at four points around the burned area (laser: 5 J/cm(2) per site). The illumination with PL was performed according to the manufacturers instructions. Treatments were repeated at 24-h intervals for 7 d. The animals were sacrifice at 3, 5, and 7 d post-burn. The specimens were routinely cut and stained and analyzed by light microscopy using hematoxylin and eosin and Sirius red. RESULTS The analysis of the results demonstrated that the damaged tissue was able to efficiently absorb and process the light at all tested wavelengths. LPBM at 660 nm showed better results at early stages of wound healing. However, the use of 780-nm laser light had beneficial effects throughout the experimental period, with the animals growing newly-formed tissue similar to normal dermis. CONCLUSION Despite our findings that the use of both types of light energy improved the healing of second-degree burns at the early stages, long-term assessment is needed to verify if this improvement will influence the final results of treatment.

Evaluation of Laser Phototherapy in the Inflammatory Process of the Rat's TMJ Induced by Carrageenan

AIM The aim of this study was to evaluate, by light microscopy, the effects of laser phototherapy (LPT) at 780 nm or a combination of 660 and 790 nm, on the inflammatory process of the rat temporomandibular joint (TMJ) induced by carrageen. BACKGROUND Temporomandibular disorders (TMDs) are frequent in the population and generally present an inflammatory component. Previous studies have evidenced positive effects of laser phototherapy on TMDs. However, its mechanism of action on the inflammation of the TMJ is not known yet. MATERIALS AND METHODS Eighty-five Wistar rats were divided into 9 groups: G1, Saline; G2, Saline + LPT IR; G3, Saline + LPT IR + R; G4, Carrageenan; G5, Carrageenan + LPT IR; G6, Carrageenan + LPT IR + R; G7, previous LPT + Carrageenan; G8, previous LPT + carrageenan + LPT IR; and G9, previous LPT + carrageenan + LPT IR + R, and then subdivided in subgroups of 3 and 7 days. After animal death, specimens were taken, routinely cut and stained with HE, Sirius Red, and Toluidine Blue. Descriptive analysis of components of the TMJ was done. The synovial cell layers were counted. RESULTS Injection of saline did not produced inflammatory reaction and the irradiated groups did not present differences compared to nonirradiated ones. After carrageenan injection, intense inflammatory infiltration and synovial cell layers proliferation were observed. The infrared irradiated group presented less inflammation and less synovial cell layers number compared to other groups. Previous laser irradiation did not improve the results. CONCLUSION It was concluded that the LPT presented positive effects on inflammatory infiltration reduction and accelerated the inflammation process, mainly with IR laser irradiation. The number of synovial cell layers was reduced on irradiated group.

Effects of Laser Photobiomodulation on Cutaneous Wounds Treated with Mitomycin C: A Histomorphometric and Histological Study in a Rodent Model

AIM The aim of the present study was to assess histologically the effect of Laser Photobiomodulation (LPBM) on skin wounds treated with Mitomycin C (MMC). BACKGROUND DATA Wound healing occurs because of a competitive mechanism between the synthesis and lyses of collagen. Therefore, any factor that increases the lyses or reduces the synthesis of collagen may result in changes in the healing process. MMC is an antineoplastic drug that inhibits fibroblast proliferation, collagen synthesis, and neoangiogenesis. LPBM has been shown to stimulate wound healing, increasing the production of collagen, fibroblastic proliferation, and angiogenesis. MATERIALS AND METHODS Forty-eight Wistar rats were randomly distributed into 4 main groups (n = 12): G1--control (G1a--7 d and G1b--14 d); G2--MMC (G2a--7 d and G2b--14 d); G3--MMC + lambda660 nm laser (G3a--7 d and G3b--14 d); and G4--MMC + lambda790 nm laser (G4a--7 d and G4b--14 d). Under general anesthesia, one excisional wound was created on the dorsum of each animal. Two ml of MMC solution was applied to the wound 4 h after surgery for 5 min. LPBM was performed on groups G3 (lambda690 nm; 20 J/cm(2); 30 mW; Phi = 2 mm) and G4 (lambda790 nm; 20 J/cm(2); 40 mW; Phi = 2 mm), starting immediately after the application of the MMC and repeated every other day during the experimental period. Laser light was applied transcutaneously at 4 equidistant points on the wound margin (4 x 5 J/cm(2), 20 J/cm(2)/session). The specimens were routinely cut and processed to wax. The slides were stained with HE and Sirius red. Computerized hystomorphometry was performed. RESULTS LPBM resulted in reduced inflammation and an increase in both fibroblast proliferation and collagen deposition. CONCLUSION The use of LPBM improves wound healing in subjects treated with MMC.

Biomodulative effects of visible and IR laser light on the healing of cutaneous wounds of nourished and undernourished Wistar rats.

AIM We evaluated histologically the differences in the healing of cutaneous wounds on nourished or undernourished rats following laser phototherapy (LPT) (20 or 40 J/cm2). BACKGROUND Wound healing occurs due to a competitive mechanism between the synthesis and lysis of collagen. Any factor that increases the lysis or reduces the synthesis of collagen may change the healing process. Nutritional deficiencies have a great effect on wound healing. METHODS Fifty nourished or undernourished Wistar rats had one standardized wound created on the dorsum and were divided into 10 subgroups: Control (standard diet); Control [Northeastern Brazilian basic diet (DBR)]; Standard diet+LPT (lambda635 nm; spatial average energy fluence (SAEF) 20 J/cm2); Standard diet+LPT (lambda635 nm; SAEF 40 J/cm2); Standard diet+LPT (lambda780 nm; SAEF 20 J/cm2); Standard diet+LPT (lambda780 nm; SAEF 40 J/cm2); DBR+LPT (lambda635 nm; SAEF 20 J/cm2); DBR+LPT (lambda635 nm; SAEF 40 J/cm2); DBR+LPT (lambda780 nm; SAEF 20 J/cm2); DBR+LPT (lambda780 nm; SAEF 40 J/cm2). The first application of the treatment was carried out immediately and repeated daily for seven days. The specimens were routinely processed to wax, cut, stained with H&E and Sirius Red stains, and analyzed using light microscopy. The analyses included re-epithelization, inflammatory infiltrate, and fibroblastic proliferation. Sirius Red stained slides were used to perform descriptive analyses of the collagen fibers. RESULTS The results showed that LPT with lambda635 wavelength was more effective for the treatment of undernourished subjects, treated with either LPT with lambda730 nm with SAEF of 20 J/cm2 or lambda780 nm with SAEF of 40 J/cm2. CONCLUSION Nutritional status influenced the progression of the healing process as well as the quality of the healed tissue. In addition, the use of both wavelengths resulted in a positive biomodulatory effect on both nourished and undernourished subjects.

Assessment of LED (λ 850 ± 10 nm) phototherapy in the inflammatory process of rat’s TMJ induced by carrageenan

Temporomandibular disorders (TMD) are commonly found in the population and usually involve inflammatory processes. Previous studies have shown positive effects of LED (Light emitting diodes) phototherapies on TMD but its action and mechanism in the inflammatory infiltrate of the temporomandibular joint are still poorly understood. The aim of this study was to assess through histological analysis the effectiveness LED (10 J/cm2, λ850 nm, 100 mW, CW) on the inflammation of the temporomandibular joint of rats induced by carrageenan. Thirty animals were divided in two groups with five animals per subgroup according to the experimental times of two, three and seven days: Inflammation and Inflammation + LED phototherapy. The first irradiation was performed 24 h after induction with an interval of 48 h between sessions. After animal death, specimens were processed and stained with HE and Picrosirius. Then the samples were examined histologically. Data were statistically analyzed. The inflammation group showed mild to moderate chronic inflammatory infiltrate among the bone trabecules of the condyle. Over the time-course of the study in the LED group the condyle showed aspects of normality and absent inflammation in some specimens. In all the time-points, no statistically significant differences were found for collagen deposition in the in the condyle and disc when LED was compared to Inflammation group. LED treated groups also demonstrated a smaller number of the layers of the synovial membrane when compared to the non-irradiated groups. It was concluded that, in general, LED phototherapy resulted in a reduction of inflammatory infiltrate in the temporomandibular joint of rat.

Influence of wavelength on the outcome of the treatment of TMJ disorders: TMDS

It is known that wavelength influences the outcome of many clinical protocols. Laser-phototherapy (LPT) and LEDs have been used on the treatment of pain of several origins including temporomandibular disorders - TMDs. TMDs are common painful multifactorial conditions affecting the temporomandibular joint whose treatment depends on the type and symptoms. Initially it requires pain control and for this, drugs, biting plates, oclusal adjustment, physiotherapy or their association are used. This work reports a series of patients of the Center of Biophotonics of the Federal University of Bahia over 10 years. Following standard anamneses, clinical and imaginologic examination and with the diagnosis of any type of TMD, the patients were set for light treatment. Treatment consisted of three sessions a week during six week. Prior irradiation, the patients were asked to score their pain using a VAS. λ780, λ 790, λ 830nm and/or λ660 and λ680nm lasers or LED were used on each session. Most patients were female (~43.6 years old). At the end of the 12 sessions the patients were again examined and score their pain using VAS. No other intervention was carried out during the treatment. The results were statistically analyzed and showed that most patients were asymptomatic or improved after treatment and that the association of wavelengths was very efficient on the symptomatic group. It is concluded that the association of both wavelengths was effective on pain reduction on TMJ disorders of several origins.

The effect of the photobiomodulation in the treatment of Bell's palsy: clinical experience

The Bells palsy (G51) consists of a unilateral face paralysis that sudden begins with unknown cause and can result in complete mimic loss or partial paralysis of the face. Damage to the VII cranial nerve can be found in the pathology, promoting mussels inactivity. The light Photobiomodulation (LPBM) has presented ability of rush the tissue repair, favoring the regeneration of neural structures. The present study aimed to assess the effectiveness use of the 780nm laser and 850nm LED (light-emitting diode) in the treatment of the face paralysis. Were evaluated 14 patients that suffer of Bells palsy whom were submitted to the light administration, on the Laser Clinic of the UFBA between 2005 and 2010. The treatment was performed by infrared Laser in 11 patients (78.57%), and by LED in 3 patients (21.42%). At the end of the 12 sections, 11 patients (78.57%) had presented themselves cure or with substantial improvement of the initial picture, however 3 patients (21.42%) dealt with infra-red Laser λ780nm had not evolution. The light presented as an effective method for the treatment of Bells palsy, but the association with the physiotherapy and medications is important.

Effectiveness of the use of LLLT on Disorders of the Maxillofacial Region

Dentistry has traditionally depended on science and technology for improvement of diagnostic tools and treatment options. The impact of using light sources in clinical Dentistry has been significantly higher than in clinical Medicine and Surgery. Light sources have been used as a therapeutic agent for many centuries. The major use of light for therapeutic applications in health care sciences was noticeably initiated after the development of lasers in 1960. The aim of this study was to evaluate the effectiveness of LLLT on treating disorders of the maxillofacial region. For this, the records of patients treated at the Laser Center of the School of Dentistry of the Federal University of Bahia were revised. We analyzed 867 treatment cycles in 572 patients. The mean age of the patients was 53.5 years old, most were females. Majority of them complained of some pain. G50.0 and K07.6 were the most frequent diagnostics. The mean energy density per session was 18.36 ± 14.6 J/cm2 and mean treatment one 176.4 ± 132.4 J/cm2. IR laser was the most frequently used wavelength. Most patients were asymptomatic or improved at discharge. Improved or asymptomatic patients had a mean age of 50.9 years old. For these, the mean number of sessions was 13, the total mean session energy density was 16.6 J/cm2 and mean total energy density treatment was 169.5 J/cm2. For symptomatic patients, the mean age was 56.4 years old. The mean number of sessions was 10. The mean energy density per session on these patients was 20.6 J/cm2 and mean total treatment energy density was 210.9 J/cm2. 55.34% of the patients were asymptomatic or improved at discharge. For these, the mean number of sessions was 13, the total mean session energy density was 16.6 J/cm2 and mean total energy density treatment was 169.5 J/cm2. For symptomatic patients, the mean age was 56.4 years old. The mean number of sessions was 10. The mean energy density per session on these patients was 20.6 J/cm2 and mean total treatment energy density was 210.9 J/cm2. The results of this study are indicative that the use of LLLT for treating different disorders of the maxillofacial region is effective and well accepted by the patients.