RESUMEN
The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve the repair, including a wide range of biomaterials and recently, photobioengineering. This work aimed to assess by histological analysis the repair of bone defects grafted with biphasic synthetic micro-granular HA + ß-TCP associated with LED phototherapy. Forty rats were divided into 4 groups (Clot, LED, Biomaterial and LED + Biomaterial) each subdivided into 2 subgroups according to the time of animal death (15 and 30 days). Surgical bone defects were prepared on the femur of each animal with a trephine drill. In animals of the Clot group the defect was filled only by blood clot, in the LED group the defect filled with the clot was further irradiated. In the animals of Biomaterial and LED + Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ = 850 ± 10 nm, 150 mW, Φ ~ 0.5 cm2, 20 J/cm2 - session, 140 J/cm2- treatment) at 48-h intervals for 2 weeks. Following animal death, samples were taken and analyzed by light microscopy. Using the degree of maturation of the bone by assessment of the deposition/organization of the basophilic lines in the newly formed bone tissue, the LED + Biomaterial group was the one in a more advanced stage of bone repair process at the end of the experiment. It may be concluded that the use of LED phototherapy was effective in positively modulating the process of bone repair of bone defects in the femur of rats submitted or not to biomaterial grafting.
Asunto(s)
Fosfatos de Calcio/farmacología , Durapatita/farmacología , Terapia por Luz de Baja Intensidad/métodos , Tibia/cirugía , Animales , Materiales Biocompatibles/farmacología , Sustitutos de Huesos/farmacología , Masculino , Ratas , Ratas Wistar , Tibia/efectos de la radiación , Cicatrización de Heridas/efectos de la radiaciónRESUMEN
The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve the repair, including a wide range of biomaterials and recently, photobioengineering. This work aimed to assess by histological analysis the repair of bone defects grafted with biphasic synthetic micro-granular HA + β-TCP associated with LED phototherapy. Forty rats were divided into 4 groups (Clot, LED, Biomaterial and LED + Biomaterial) each subdivided into 2 subgroups according to the time of animal death (15 and 30 days). Surgical bone defects were prepared on the femur of each animal with a trephine drill. In animals of the Clot group the defect was filled only by blood clot, in the LED group the defect filled with the clot was further irradiated. In the animals of Biomaterial and LED + Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ=850±10 nm, 150 mW, Φ ~ 0.5 cm2, 20 J/cm2 - session, 140 J/cm2- treatment) at 48-h intervals for 2 weeks. Following animal death, samples were taken and analyzed by light microscopy. Using the degree of maturation of the bone by assessment of the deposition/organization of the basophilic lines in the newly formed bone tissue, the LED + Biomaterial group was the one in a more advanced stage of bone repair process at the end of the experiment. It may be concluded that the use of LED phototherapy was effective in positively modulating the process of bone repair of bone defects in the femur of rats submitted or not to biomaterial grafting.
O tratamento de perdas ósseas devido a diferentes fatores etiológicos é difícil e muitas técnicas têm por objetivo melhorar o reparo incluindo o uso de uma ampla gama de biomateriais e, recentemente, a fotobioengenharia. Este trabalho teve como objetivo avaliar, por meio de análise histológica, o reparo de defeitos ósseos enxertados com HA bifásica micro-granular sintética + β -TCP associada à fototerapia LED. Quarenta ratos foram divididos em quatro grupos (Clot, LED, Biomaterial e LED + Biomaterial), subdivididos no dois subgrupos de acordo com o momento da morte (15 e 30 dias). Defeitos ósseos cirúrgicos foram criados em um fêmur de cada animal com uma broca trefina. Em animais do grupo coágulo, o defeito foi preenchido apenas pelo coágulo sanguíneo, no grupo de LED o defeito foi preenchido pelo coágulo e irradiado. Nos animais dos grupos do biomaterial e LED + biomaterial, os defeitos foram preenchidos com biomaterial e o último foi adicionalmente irradiado (λ=850±10 nm, 150 mW, Φ ~ 0.5 cm2, 20 J/cm2 - session, 140 J/cm2 -tratamento) a cada 48 h por duas semanas. Após a morte dos animais, amostras foram colhidas e analisadas por microscopia de luz, usando o grau de maturação do osso como marcador (deposição/organização das linhas basofílicas) no tecido ósseo neoformado. O grupo de LED + biomaterial apresentou processo de reparação mais avançado ao fim do experimento. Pode-se concluir que o uso da fototerapia LED foi eficaz na modulação positiva do processo de reparo ósseo de defeitos ósseos no fêmur de ratos submetidos ou não a enxerto com biomaterial.
Asunto(s)
Animales , Masculino , Ratas , Fosfatos de Calcio/farmacología , Durapatita/farmacología , Terapia por Luz de Baja Intensidad/métodos , Tibia/cirugía , Materiales Biocompatibles/farmacología , Sustitutos de Huesos/farmacología , Ratas Wistar , Tibia/efectos de la radiación , Cicatrización de Heridas/efectos de la radiaciónRESUMEN
The handling of bone losses due to different etiologic factors is difficult and many techniques are aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (~960, ~1,070, and 1,077 cm(-1)) and organic (~1,454 and ~1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of sacrifice (15 and 30 days). Surgical bone defects were made on the femur of each animal with a trephine drill. On animals of group clot, the defect was filled only by blood clot, on group LED, the defect filled with the clot was further irradiated. On animals of groups biomaterial and LED + biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ850 ± 10 nm, 150 mW, Φ ~ 0.5 cm(2), 20 J/cm(2)-session, 140 J/cm(2)-treatment) at 48-h intervals and repeated for 2 weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensity of hydroxyapatite (HA) (~960 cm(-1)) were higher on group LED + biomaterial and the peaks of both organic content (~1,454 and ~1,666 cm(-1)) and transitional HA (~1,070 and ~1,077 cm(-1)) were lower on the same group. It is concluded that the use of LED phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of HA measured by Raman spectroscopy.
Asunto(s)
Huesos/cirugía , Calcio/química , Durapatita/química , Polifosfatos/química , Espectrometría Raman , Animales , Materiales Biocompatibles/química , Huesos/efectos de la radiación , Luz , Terapia por Luz de Baja Intensidad , Masculino , Fototerapia , Ratas , Ratas Wistar , Cicatrización de HeridasRESUMEN
This work aimed to assess biochemical changes associated to mineralization and remodeling of bone defects filled with Hydroxyapatite+Beta-Beta-tricalcium phosphate irradiated or not with 2 light sources. Ratios of intensities, band position and bandwidth of selected Raman peaks of collagen and apatites were used. Sixty male Wistar rats were divided into 6 groups subdivided into 2 subgroups (15th and 30th days). A standard surgical defect was created on one femur of each animal. In 3 groups the defects were filled with blood clot (Clot, Clot+Laser and Clot+LED groups) and in the remaining 3 groups the defects were filled with biomaterial (Biomaterial, Biomaterial+Laser and Biomaterial+LED groups). When indicated, the defects were irradiated with either Laser (λ780 nm, 70 mW, Φâ¼0.4 cm(2)) or LED (λ850±10 nm, 150 mW, Φâ¼0.5 cm(2)), 20 J/cm(2) each session, at 48 h intervals/2 weeks (140 J/cm(2) treatment). Following sacrifice, bone fragments were analyzed by Raman spectroscopy. Statistical analysis (ANOVA General Linear Model, p<0.05) showed that both grafting and time were the variables that presented significance for the ratios of â¼1660/â¼1670 cm(-1) (collagen maturation), â¼1077/â¼854 cm(-1) (mineralization), â¼1077/â¼1070 cm(-1) (carbonate substitution) and the position of the â¼960 cm(-1) (bone maturation). At 30th day, the ratios indicated an increased deposition of immature collagen for both Clot and Biomaterial groups. Biomaterial group showed increased collagen maturation. Only collagen deposition was significantly dependent upon irradiation independently of the light source, being the amount of collagen I increased in the Clot group at the end of the experimental time. On the other hand, collagen I deposition was reduced in biomaterial irradiated groups. Raman ratios of selected protein matrix and phosphate and carbonate HA indicated that the use of biphasic synthetic micro-granular HA+Beta-TCP graft improved the repair of bone defects, associated or not with Laser or LED light, because of the increasing deposition of HA.
Asunto(s)
Huesos/efectos de la radiación , Rayos Láser , Luz , Espectrometría Raman , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/uso terapéutico , Coagulación Sanguínea , Enfermedades Óseas/radioterapia , Enfermedades Óseas/cirugía , Regeneración Ósea , Trasplante Óseo , Huesos/química , Fosfatos de Calcio/química , Colágeno Tipo I/metabolismo , Durapatita/química , Terapia por Luz de Baja Intensidad , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through histological analysis The aim of this study was to assess, by light microscopy, the repair of bone defects grafted or not with biphasic synthetic micro-granular Calcium hydroxyapatite (HA)+Beta-TCP associated or not with Laser phototherapy - LPT (λ780nm). Forty rats were divided into 4 groups each subdivided into 2 subgroups according to the time of sacrifice (15 and 30days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of Clot group the defect was filled only by blood clot, on Laser group the defect filled with the clot was further irradiated. On animals of Biomaterial and Laser+Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ780nm, 70mW, spot sizeâ¼0.4cm(2), 20J/cm(2)-session, 140J/cm(2)-treatment) in four points around the defect at 48-h intervals and repeated for 2weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by light microscopy. Many similarities were observed histologically between groups on regards bone reabsorption and neoformation, inflammatory infiltrate and collagen deposition. The criterion degree of maturation, marked by the presence of basophilic lines, indicated that the use of LPT associated with HA+Beta TCP graft, resulted in more advanced stage of bone repair at the end of the experiment.
Asunto(s)
Materiales Biocompatibles , Huesos/cirugía , Fosfatos de Calcio/uso terapéutico , Durapatita/uso terapéutico , Terapia por Luz de Baja Intensidad/métodos , Animales , Sustitutos de Huesos/uso terapéutico , Huesos/patología , Masculino , Ratas Wistar , Cicatrización de HeridasRESUMEN
The treatment of bone loss due to different etiologic factors is difficult, and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (â¼ 960, â¼ 1,070, and â¼ 1,077 cm(-1)) and organic (â¼ 1,454 and â¼ 1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of killing (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot, the defect was filled only by blood clot; on group Laser, the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser + Biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ â¼ 0.4 cm(2), 20 J/cm(2) session, 140 J/cm(2) treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th day following killing, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensities of both inorganic and organic contents were higher on group Laser + Biomaterial. It is concluded that the use of laser phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of calcium hydroxyapatite measured by Raman spectroscopy.
Asunto(s)
Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/efectos de la radiación , Fosfatos de Calcio/uso terapéutico , Durapatita/uso terapéutico , Rayos Láser , Terapia por Luz de Baja Intensidad , Polifosfatos/uso terapéutico , Animales , Materiales Biocompatibles/química , Coagulación Sanguínea/efectos de los fármacos , Huesos , Calcio , Calcio de la Dieta , Fémur , Luz , Masculino , Ratas , Ratas Wistar , Espectrometría Raman , Tibia/efectos de los fármacos , Tibia/efectos de la radiación , Cicatrización de HeridasRESUMEN
Use of biomaterials and light on bone grafts has been widely reported. This work assessed the influence of low-level laser therapy (LLLT) on bone volume (BV) and bone implant contact (BIC) interface around implants inserted in blocks of bovine or autologous bone grafts (autografts), irradiated or not, in rabbit femurs. Twenty-four adult rabbits were divided in 8 groups: AG: autograft; XG: xenograft; AG/L: autograft + laser; XG/L: xenograft + laser; AG/I: autograft + titanium (Ti) implant; XG/I: xenograft + Ti implant; AG/I/L: autograft + Ti implant + laser; and XG/I/L: xenograft + Ti implant + laser. The animals received the Ti implant after incorporation of the grafts. The laser parameters in the groups AG/L and XG/L were λ=780 nm, 70 mW, CW, 21.5 J/cm 2 , while in the groups AG/I/L and XG/I/L the following parameters were used: λ=780 nm, 70 mW, 0.5 cm 2 (spot), 4 J/cm 2 per point (4), 16 J/cm 2 per session, 48 h interval × 12 sessions, CW, contact mode. LLLT was repeated every other day during 2 weeks. To avoid systemic effect, only one limb of each rabbit was double grafted. All animals were sacrificed 9 weeks after implantation. Specimens were routinely stained and histomorphometry carried out. Comparison of non-irradiated and irradiated grafts (AG/L versus AG and XG/L versus XG) showed that irradiation increased significantly BV on both grafts (p=0.05, p=0.001). Comparison between irradiated and non-irradiated grafts (AG/I/L versus AG/I and XG/I/L versus XG/I) showed a significant (p=0.02) increase of the BIC in autografts. The same was seen when xenografts were used, without significant difference. The results of this investigation suggest that the use of LLLT is effective for enhancing new bone formation with consequent increase of bone-implant interface in both autologous grafts and xenografts.
Asunto(s)
Autoinjertos/trasplante , Trasplante Óseo/métodos , Implantes Dentales , Xenoinjertos/trasplante , Terapia por Luz de Baja Intensidad/métodos , Osteogénesis/fisiología , Animales , Autoinjertos/patología , Autoinjertos/efectos de la radiación , Bovinos , Materiales Dentales/química , Diseño de Prótesis Dental , Femenino , Fémur/patología , Fémur/cirugía , Xenoinjertos/patología , Xenoinjertos/efectos de la radiación , Tamaño de los Órganos , Oseointegración/fisiología , Oseointegración/efectos de la radiación , Osteogénesis/efectos de la radiación , Conejos , Dosificación Radioterapéutica , Titanio/químicaRESUMEN
Use of biomaterials and light on bone grafts has been widely reported. This work assessed the influence of low-level laser therapy (LLLT) on bone volume (BV) and bone implant contact (BIC) interface around implants inserted in blocks of bovine or autologous bone grafts (autografts), irradiated or not, in rabbit femurs. Twenty-four adult rabbits were divided in 8 groups: AG: autograft; XG: xenograft; AG/L: autograft + laser; XG/L: xenograft + laser; AG/I: autograft + titanium (Ti) implant; XG/I: xenograft + Ti implant; AG/I/L: autograft + Ti implant + laser; and XG/I/L: xenograft + Ti implant + laser. The animals received the Ti implant after incorporation of the grafts. The laser parameters in the groups AG/L and XG/L were λ=780 nm, 70 mW, CW, 21.5 J/cm 2 , while in the groups AG/I/L and XG/I/L the following parameters were used: λ=780 nm, 70 mW, 0.5 cm 2 (spot), 4 J/cm 2 per point (4), 16 J/cm 2 per session, 48 h interval × 12 sessions, CW, contact mode. LLLT was repeated every other day during 2 weeks. To avoid systemic effect, only one limb of each rabbit was double grafted. All animals were sacrificed 9 weeks after implantation. Specimens were routinely stained and histomorphometry carried out. Comparison of non-irradiated and irradiated grafts (AG/L versus AG and XG/L versus XG) showed that irradiation increased significantly BV on both grafts (p=0.05, p=0.001). Comparison between irradiated and non-irradiated grafts (AG/I/L versus AG/I and XG/I/L versus XG/I) showed a significant (p=0.02) increase of the BIC in autografts. The same was seen when xenografts were used, without significant difference. The results of this investigation suggest that the use of LLLT is effective for enhancing new bone formation with consequent increase of bone-implant interface in both autologous grafts and xenografts.
O uso de biomateriais e luz em enxertos ósseos têm sido relatados. Esse trabalho avaliou a influência do laser baixa potência - LBP no volume ósseo (VO) e superfície de contato osso-implante (COI) ao redor de implantes dentários inseridos em blocos de enxerto bovino ou autólogos incorporados, irradiados ou não, em fêmures de coelho. Vinte e quatro coelhos adultos foram divididos em 8 grupos: EA: enxerto autólogo; EX: enxerto xenógeno; EA/L: enxerto autólogo + laser; EX/L: enxerto xenógeno + laser; EA/I: enxerto autólogo + implante; EX/I: enxerto xenógeno + implante; EA/I/L: enxerto autólogo + implante de titânio + laser; EX/I/L: enxerto xenógeno + implante de titânio + laser. Os animais receberam um implante de titânio após a incorporação dos enxertos. Os parâmetros de laser nos grupos EA/L e EX/L foram λ =780 nm, 70 mW, CW, 21,5 J/cm 2 ), enquanto que nos grupos EA/I/L e EX/I/L os seguintes parâmetros de laser foram utilizados: λ =780 nm, 70 mW, 0,5 cm 2 (spot), 4 J/cm 2 por ponto (4), 16 J/cm 2 por sessão, intervalo de 48 h × 12 sessões, CW, modo contato. O LBP foi repetido a cada 48 h (2 semanas). Para evitar efeito sistêmico apenas um membro de cada coelho foi duplamente enxertado. Todos os animais foram sacrificados 9 semanas após o implante. Os espécimes foram corados rotineiramente e histomorfometria foi realizada. A comparação dos enxertos não-irradiados e irradiados (EA/L versus EA e EX/L versus EX) mostrou que a irradiação aumentou significantemente (p=0,02) o VO para ambos os tipos de enxertos (p=0,05, p=0,001). A comparação dos enxertos não-irradiados e irradiados (EA/I/L versus EA/I e EX/I/L versus EX/I) mostrou um aumento significante (p=0,02) do COI nos enxertos autólogos e xenógenos sem diferença estatística. Os resultados desta investigação sugerem que o uso de LBP é efetivo para aumentar a neoformação óssea com consequente aumento do COI em enxertos autólogos e xenógenos.
Asunto(s)
Animales , Bovinos , Femenino , Conejos , Autoinjertos/trasplante , Trasplante Óseo/métodos , Implantes Dentales , Xenoinjertos/trasplante , Terapia por Luz de Baja Intensidad/métodos , Osteogénesis/fisiología , Autoinjertos/patología , Autoinjertos/efectos de la radiación , Diseño de Prótesis Dental , Materiales Dentales/química , Fémur/patología , Fémur/cirugía , Xenoinjertos/patología , Xenoinjertos/efectos de la radiación , Tamaño de los Órganos , Oseointegración/fisiología , Oseointegración/efectos de la radiación , Osteogénesis/efectos de la radiación , Dosificación Radioterapéutica , Titanio/químicaRESUMEN
OBJECTIVES: The aim of this research was to investigate the influence of low-power laser on tooth movement in rats. BACKGROUND: Tooth movement is closely related to the process of bone remodeling. The biologic result, with the application of a force to the tooth, is bone absorption on the pressure side and neoformation on the traction side of the alveolar bone. The laser photobiomodulation is capable of providing an increase in cellular metabolism, blood flow, and lymphatic drainage. METHODS: Thirty young-adult male Wistar rats weighing between 250 and 300 g were divided into two groups, control and experimental, containing 15 animals each. The animals received orthodontic devices calibrated to release a force of 40 g/F, with the purpose of moving the first upper molar mesially. Low-intensity laser, wavelength 790 nm, was used in the experimental group; the dose was 4.5 J/cm(2) per point, mesial and distal, on the palatal side, 11 J/cm(2) on the buccal side, and this procedure was repeated every 48 h, totaling nine applications. The active movement was clinically evaluated after 7, 13, and 19 days. RESULTS AND CONCLUSION: The results showed no statistically significant difference, p = 0.079 (T0-T7), p = 0.597 (T7-T13), and p = 0.550 (T13-T19) between the laser and control groups on the amount of tooth movement in the different times evaluated. It may be concluded that laser phototherapy, with the parameters in the present study, did not significantly increase the amount of tooth displacement during induced orthodontic movement in rodents.
Asunto(s)
Terapia por Luz de Baja Intensidad , Técnicas de Movimiento Dental , Animales , Masculino , Aparatos Ortodóncicos , Conejos , Ratas , Ratas WistarRESUMEN
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.
Asunto(s)
Diabetes Mellitus Experimental , Supervivencia de Injerto/efectos de la radiación , Terapia por Luz de Baja Intensidad , Colgajos Quirúrgicos , Animales , Masculino , Distribución Aleatoria , Ratas , Ratas WistarRESUMEN
The aim of the investigation was to assess histologically the effect of laser photobiomodulation (LPBM) on a repair of defects surgically created in the femurs of rats. Forty-five Wistar rats were divided into four groups: group I (control); group II (LPBM); group III (hydroxyapatite guided bone regeneration; HA GBR); group IV (HA GBR LPBM). The animals in the irradiated groups were subjected to the first irradiation immediately after surgery, and it was repeated every day for 2 weeks. The animals were killed 15 days, 21 days and 30 days after surgery. When the groups irradiated with implant and membrane were compared, it was observed that the repair of the defects submitted to LPBM was also processed faster, starting from the 15th day. At the 30th day, the level of repair of the defects was similar in the irradiated groups and those not irradiated. New bone formation was seen inside the cavity, probably by the osteoconduction of the implant, and, in the irradiated groups, this new bone formation was incremental. The present preliminary data seem to suggest that LPMB therapy might have a positive effect upon early wound healing of bone defects treated with a combination of HA and GBR.
Asunto(s)
Materiales Biocompatibles/uso terapéutico , Regeneración Ósea/efectos de la radiación , Durapatita/uso terapéutico , Fémur/patología , Regeneración Tisular Dirigida/métodos , Terapia por Luz de Baja Intensidad , Animales , Terapia Combinada , Femenino , Fémur/fisiopatología , Fémur/efectos de la radiación , Masculino , Ratas , Ratas WistarRESUMEN
OBJECTIVE: This study assessed histologically the effect of laser photobiomodulation (LPBM) on the repair of surgical defects created in the femurs of Wistar rats treated or not treated with bone morphogenic proteins (BMPs) and organic bovine bone graft. BACKGROUND DATA: This paper is part of an ongoing series of works in which biomaterials are used in association with LPBM. Several previous reports by our group have shown that the use of laser photobiomodulation improves the treatment of bone defects. MATERIALS AND METHODS: Forty-eight adult male Wistar rats were divided into four randomized groups: group I (control, n = 12); group II (LPBM, n = 12); group III (BMPs + organic bovine bone graft, n = 12); and group IV (BMPs + organic bovine bone graft + LPBM, n = 12). The irradiated groups received seven irradiations every 48 h, beginning immediately after the surgical procedure. The laser therapy (lambda = 830 nm, 40 mW CW, varphi = 0.6 mm) consisted of 16 J/cm(2) per session divided equally over four points (4 J/cm(2) each) around the defect. The subjects were sacrificed after 15, 21, and 30 d, and the specimens were routinely embedded in wax, stained with hematoxylin and eosin and sirius red, and analyzed under light microscopy. RESULTS: The results showed histological evidence of increased deposition of collagen fibers (at 15 and 21 d), as well as an increased amount of well-organized bone trabeculae at the end of the experimental period (30 d) in the irradiated animals versus the non-irradiated controls. CONCLUSION: The use of LPBM with BMPs and organic bovine bone grafts increases the positive biomodulating effects of laser light.
Asunto(s)
Materiales Biocompatibles/administración & dosificación , Proteínas Morfogenéticas Óseas/administración & dosificación , Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/efectos de la radiación , Rayos Infrarrojos/uso terapéutico , Terapia por Luz de Baja Intensidad/métodos , Animales , Fémur/efectos de los fármacos , Fémur/fisiopatología , Fémur/efectos de la radiación , Masculino , Ratas , Ratas WistarRESUMEN
OBJECTIVE: The aim of the present study was to assess histologically the effect of low-level laser thrapy (LLLT) (lambda 830 nm) on the healing of bone defects associated with autologous bone graft. BACKGROUND DATA: LLLT has been used on the modulation of bone healing because of the photo-physical and photochemical properties of some wavelengths. The use of correct and appropriate parameters has been shown to be effective in the promotion of a positive biomodulative effect on the healing bone. METHODS: Sixty male Wistar rats were divided into four groups: G1 (control), G2 (LLLT on the surgical bed), G3 (LLLT on the graft), and G4 (LLLT on both the graft and the surgical bed). The dose per session was 10 J/cm(2), and it was applied to the surgical bed (G2/G4) and on the bone graft (G3/G4). LLLT was carried out every other day for 15 days (lambda 830 nm, phi = 0.5 cm(2), 50 Mw, 10 J/cm(2)). The dose was fractioned in four points. The animals were sacrificed 15, 21, and 30 days after surgery; specimens were taken and routinely processed (wax, cut, and stain with H&E and Sirius red stains). Light microscopic analysis was performed by a pathologist. RESULTS: In the groups in which the LLLT was used trans-operatively on the surgical bed (G2/G4), bone remodeling was both quantitatively and qualitatively more evident when compared to subjects of groups G1 and G3. CONCLUSION: The present study indicates that the use of LLLT trans-operatively resulted in a positive biomodulative effect on the healing of bone defects associated with autologous bone grafts.
Asunto(s)
Remodelación Ósea/efectos de la radiación , Fémur/efectos de la radiación , Terapia por Luz de Baja Intensidad , Animales , Trasplante Óseo , Fémur/trasplante , Masculino , Ratas , Ratas Wistar , Trasplante AutólogoRESUMEN
OBJECTIVE: This study aimed to describe, through morphologic and cytochemical analysis, the healing process of wounds submitted (or not) to laser therapy (lambda685 nm) or polarized light (lambda400-2000 nm). BACKGROUND DATA: There are many reports on different effects of several types of phototherapies on the treatment of distinct conditions, amongst them, on wound healing. Laser therapy and the use of polarized light are still controversial despite successive reports on their positive effects on several biological processes. METHODS: Thirty male Wistar rats, approximately 4 months old, were used, and standardized excisional wounds were created on their dorsum. The wounds were irradiated in four equidistant points with laser light or illuminated with polarized light, both with doses of 20 or 40 J/cm2. Group 1 acted as untreated controls. Animals were irradiated every 48 h during 7 days, starting immediately after surgery, and were humanely killed on the 8th post-operative day. Specimens were taken and routinely processed and stained with H&E, and for descriptive analysis of myofibroblasts and collagen fibers, the specimens were imunnomarked by smooth muscle alpha-actin and picrosirius stain. RESULTS: Control specimens showed the presence of ulceration, hyperemia, discrete edema, intense, and diffuse inflammation, collagen deposition was irregular, and myofibroblasts were seen parallel to the wound margins. Wounds treated by laser therapy with a dose of 20 J/cm2 showed mild hyperemia, inflammation varied from moderate to intense, the number of fibroblasts was large, and the distribution of collagen fibers was more regular. Increasing the dose to 40 J/cm2 evidenced exuberant neovascularization, severe hyperemia, moderate to severe inflammation, large collagen deposition, and fewer myofibroblasts. On subjects illuminated with polarized light with a dose of 20 J/cm2, mild to moderate hyperemia was detectable, and collagen matrix was expressive and unevenly distributed; a larger number of myofibroblasts was present and no re-epithelialization was seen. Increasing the dose resulted in mild to moderate hyperemia, no re-epithelialization was seen, edema was discrete, and inflammation was moderate. CONCLUSION: The use of 685-nm laser light or polarized light with a dose of 20 J/cm2 resulted in increased collagen deposition and better organization on healing wounds, and the number of myofibroblast was increased when polarized light is used.
Asunto(s)
Rayos Láser , Terapia por Luz de Baja Intensidad/métodos , Cicatrización de Heridas/fisiología , Heridas y Lesiones/patología , Heridas y Lesiones/radioterapia , Animales , Biopsia con Aguja , Modelos Animales de Enfermedad , Inmunohistoquímica , Masculino , Fotomicrografía , Probabilidad , Distribución Aleatoria , Ratas , Ratas Wistar , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: The objective of the present investigation was to assess the histological effects of different wavelengths and intensities on the healing process of cutaneous wounds. BACKGROUND DATA: Tissue repair is a dynamic interactive process which involves mediators, cells and extra-cellular matrix. Several reports on the use of laser therapy have shown that the healing process is positively affected when the correct parameters are used. METHODS: Eighteen standardized wounds were surgically created on the dorsum of male and female Wistar rats, which were subsequently divided into two experimental groups according to wavelength used lambda.670 or lambda685 nm) for lasertherapy (LLLT). Each group was divided into three subgroups of three animals according to the intensity of the applied irradiation (2, 15, or 25 mW). Twelve animals were used as untreated controls and were not irradiated. The irradiation was carried out during seven consecutive days. The animals were sacrificed eight days after surgery. The specimens were removed, kept in 4% formaldehyde for 24 h, routinely prepared to wax, stained with H&E, and analyzed under light microscopy. RESULTS: For both groups, light microscopy showed a substitution repair process; however, when LLLT was used, a positive biomodulatory effect was detectable, chiefly associated with shorter wavelength and low intensity. CONCLUSIONS: The results of the present study indicate that LLLT improved cutaneous wound repair and that the effect is a result of an inversely proportional relationship between wavelength and intensity, with treatment more effective when combining higher intensity with short wavelength or lower intensity with higher wavelength.