Nicole Ribeiro Silva Santos

Influence of the Combination of Infrared and Red Laser Light on the Healing of Cutaneous Wounds Infected by Staphylococcus aureus

AIM We aimed to assess the use of two wavelengths on the healing of infected wounds. BACKGROUND Infection is the most significant cause of impaired wound repair or healing. Several therapeutic approaches are used for improving wound healing including the use of different light sources, such as the laser. Some wavelengths yield positive photobiological effects on the healing process. MATERIAL AND METHODS The backs of 24 young adult male Wistar rats under general anesthesia were shaved and cleaned, and a 1 by 1 cm cutaneous wound was created with a scalpel and left untreated. The wounds were infected with Staphylococcus aureus, and the rats were randomly divided into two sets of four subgroups with three animals in each subgroup: control, red laser light, infrared laser light, and red + infrared laser light. Laser phototherapy was carried out with a diode [λ680 nm/790 nm, power (P) = 30 mW/40 mW, continuous wave laser, Ø = 3 mm, power density (P) = 424 and 566 mW/cm(2), time = 11.8/8.8 sec, E = 0.35 J] and started immediately after surgery and repeated every other day for 7 d. Laser light was applied on four points around the wounded area (5 J/cm(2)). The animals were killed either 8 or 15 d after contamination. Specimens were taken, embedded in paraffin, and sectioned and stained for histological analysis. RESULTS Histological analysis showed that control subjects had a lower amount of blood vessels when compared with irradiated subjects. Irradiated subjects had more advanced resolution of inflammation compared with controls. Irradiated subjects also showed a more intense expression of the collagen matrix. The collagen fibers were mostly mature and well organized in these subjects at the end of the experimental time especially when both wavelengths were used. CONCLUSION The results of the present study indicate that laser phototherapy has a positive effect on the healing of infected wounds, particularly with the association of λ680 + λ790 nm.

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.

Removal of oral lichen planus by CO2 laser

The aim of this case report is to present a histologically diagnosed oral lichen planus excised by the CO2 laser. Oral lichen planus is a chronic inflammatory mucocutaneous disease of unknown etiology. Different treatments have been used to manage this condition. A 46 year-old female was referred to the Laser Clinic of the Dental School of the Federal University of Bahia to excise a lesion characterized by white patches on the oral mucosa, which was causing pain and burning sensation and had not respond to treatment with triamcinolone and corticosteroids for 3 months. CO2 laser was used to remove the lesion and the conclusive histopathological diagnosis was oral lichen planus. The patient was followed up over 1 year with no signs of lesion recurrence. The use of the CO2 laser was found to be useful and effective to treat lichen planus.

Surgical treatment of oral lymphangiomas with CO2 laser: report of two uncommon cases

This paper reports the treatment of oral lymphangiomas with carbon dioxide CO₂ Laser. Lymphangiomas are rare congenital lymphatic malformations. These lesions are most frequently diagnosed during childhood, are most commonly located in the head and neck region, and are extremely rare in the oral cavity. Oral lymphangiomas are of complex treatment due to the difficulty in performing a complete excision. CO₂ laser is the most often used laser in the oral cavity due to its affinity with water and high absorption by the oral mucosa. Several benefits of the use of CO₂ laser have been reported for surgical oral procedures. The cases reported herein were biopsy-proven lymphangiomas of the oral cavity. The surgical procedures were carried out under local anesthesia and a focused CO₂ laser beam (λ10.600 nm, Φ ~2 mm, CW/RSP) was used. At the end of the surgery, the laser beam was used on a defocused mode to promote better hemostasis. Neither sutures nor dressings were used after surgery. No medication and only mouthwashes were prescribed to all patients on the postoperative period. There were no postsurgical complaints from the patients and no relapses of the conditions were observed after follow-up periods of 12 and 18 months. The use of CO₂ laser was practical, easy to carry out and effective on the treatment of oral lymphangiomas, with no lesion recurrence.

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.

A Feasible Procedure in Dental Practice: The Treatment of Oral Dysplastic Hyperkeratotic Lesions of the Oral Cavity with the CO2 Laser

OBJECTIVES The aim of this work is to report some cases of surgical removal of hyperkeratotic lesions of the oral cavity with the CO(2) laser. BACKGROUND Hyperkeratosis is an abnormal thickening of the stratum corneum caused by increased deposition of keratin, and its histopathologic features show wide variations. These changes are significant because they determine different biologic behavior. Several techniques are used to treat these lesions, including scalpel incision, electrosurgery, cryosurgery, photodynamic therapy, and some drugs. The use of surgical lasers has been proposed as an effective way of treating such lesions safely. The CO(2) laser is the most used laser on the oral cavity because of its affinity for water and high absorption by the oral mucosa. Several benefits of the use of the CO(2) laser are reported in the literature in regard to surgical procedures carried out on the oral cavity. PATIENTS AND METHODS All patients had histopathologic diagnosis of hyperkeratosis and mild epithelial dysplasia and were routinely prepared for surgery under local anesthesia. The surgical procedures were carried out by using a CO(2) laser (Sharplan 20 C; Laser Industries, Tel Aviv, Israel, λ10,600 nm, φ∼2 mm, CW/RSP). The beam was focused to delimit each lesion, and then lesions were excised, and the removed specimens were sent for histopathology. At the end of the surgery, the beam was used in a defocused manner to promote better hemostasis. Neither sutures nor dressings were used after the surgery. No medication but mouthwashes was prescribed to all patients in the postoperative period. CONCLUSIONS The use of the CO(2) laser does not reduce the risk of relapses of the lesion, but it is an easy-to-use technique and results in both a quick surgical procedure and trouble-free postoperative period and may be safely used in dental practice.

Influence of phototherapies on the outcome of complete tibial fractures grafted or not with MTA: Raman spectroscopic study on rabbits

The aim of the present study was to assess, by means of Raman spectroscopy, the repair of complete surgical tibial fractures fixed with wire osteosynthesis or miniplates treated or not with infrared laser (λ780 nm) or infrared LED (λ850 ± 10 nm) lights, 142.8 J/cm2 per treatment, associated or not to the use of mineral trioxide aggregate (MTA) cement. Surgical fractures were created on 36 rabbits and fixed with WO or miniplates and some groups were grafted with MTA. Irradiated groups received lights at every other day for 15 days and sacrifice occurred after 30 days. The results showed that only irradiation with either laser or LED influenced the peaks of phosphate (~960 cm-1) and carbonated (~1,070 cm-1) hydroxyapatite. Collagen peak (1,450 cm-1) was influenced by both the use of MTA and irradiation with either laser or LED. It is concluded that the use of either laser or LED phototherapy associated to MTA cement was efficacious on improving the repair of complete tibial fractures treated with wire osteosynthesis or miniplates.

Assessment of the influence of Laser phototherapy on the bone repair process of complete fractures in tibiae of rabbits stabilized with semi-rigid internal fixation treated with or without MTA graft: a histological study

Beside biomaterials, Laser phototherapy has shown positive effects as auxiliary therapy in bone repair process, especially when involving large bone losses. The aim of this histological study was to evaluate, by light microscopy, the influence of laser phototherapy on the repair of complete tibial fractures in rabbits treated or not with semi-rigid internal fixation and Mineral Trioxide Aggregate - MTA graft. Twelve Rabbits were randomly divided into four groups with three animals each. After general anesthesia, complete fractures were created in one tibia with a carborundum disk. All animals (groups I-IV) had the fracture stabilized with semi-rigid fixation (wire osteosynthesis - WO). Group I was routinely fixed with WO; groups II and IV fracture was filled by blood clot and MTA implant. In Groups III and IV fracture was filled by blood clot and further irradiated with laser (λ780 nm, 70 mW, CW, Φ = 0.04 cm2, 20.4 J/cm2, per session, t = 300s, 142.8 J/cm2 per treatment). The phototherapy protocol was applied immediately after the surgery and repeated each 48 hours during 15 days. Animal death occurred on the 30th postoperative day. After removal of the specimens, the samples were routinely processed, stained with HE and evaluated by light microscopy. Histologically, the group treated with MTA graft and irradiated with laser showed the fracture filled by a more organized and mature trabecular bone, when compared with all other groups. From the results of the present study, it may be concluded that the association of Laser phototherapy + MTA graft in fractures treated with WO improved bone repair when compared with fractures treated only with WO.

Evaluation of healing of infected cutaneous wounds treated with different energy densities

We aimed assess the effects of different energy densities of the association of red/IR laser light on the healing of cutaneous wounds infected Staphylococcus aureus. Background: Wound infection is the most common complication on healing wounds and cause both vascular and cellular responses on the tissue. Several therapeutics is used for improving wound healing including the use of different light sources, such as the Laser. Some energy densities present positive photobiological effects on the healing process. Material and Methods: 24 young adult male Wistar rats, under general anesthesia, had their dorsum shaven, cleaned and a 1 x 1cm cutaneous wound created with a scalpel and left without no suturing or dressings. The wounds were infected with Staphylococcus aureus and were randomly divided in 8 subgroups of 3 animals in each: Control, Group 10J/cm2, Group 20J/cm2, and Group 30J/cm2, 7 and 14 days each group. Laser phototherapy was carried out with a diode (λ680nm/790nm, P= 30mW/40mW, CW, Laser, Ø = 3mm, PD=424mW/cm2 and 566mW/cm2, t=11.8/ 8.8 sec, E=0.35J) and started immediately after surgery and repeated at every other day during 7 days. Laser light was applied on 4 points around wounded area. The animals were killed at either 8th or 15th day after contamination. Specimens were taken, routinely cut and processed to wax, stained and underwent histological analysis. The results were statistically analyzed. Results: Both 20 and 30J/cm2 caused intense collagen deposition at the end of the experimental time. But, when 20 J/cm2 was used the fibers were also well organized. Conclusion: Our results indicate that irradiated subjects showed improved wound healing being the 20 J/cm2 the energy the caused better histological response.

Effects of LED Phototherapy on Bone Defects Grafted with MTA in a Rodent Model: A Description of the Bone Repair by Light Microscopy

We carried out a histological analysis on bone defects grafted (MTA) treated or not with LED, BMPs and GBR. Benefits of the isolated or combined use these techniques on bone repair have been suggested, but there is no report on their association with LED light. 36 rats were divided into 4 groups each subdivided into 3. Defects on G II and I were filled with the blood clot. G II was further irradiated with LED. G III‐IV were filled with MTA+Collagen gel; G IV was further irradiated. LED was applied over the defect at 48 h intervals and repeated for 15 days. Specimens were processed, cut and stained with H&E and Sirius red and underwent histological analysis. The results showed that MTA, due to its characteristics seemed not being directly affected by the LED light. But, the use of LED positively affect bone repair similarly to what was observed on different studies by our team using other biomaterials and laser. It is concluded that MTA seems not be directed affected by the LED light due to it characterist...