Low-level laser therapy prevents degenerative morphological changes in an experimental model of anterior cruciate ligament transection in rats.

The aim of this study was to analyze the effects of low-level laser therapy (LLLT) on the prevention of cartilage damage after the anterior cruciate ligament transection (ACLT) in knees of rats. Thirty male rats (Wistar) were distributed into three groups (n = 10 each): injured control group (CG); injured laser-treated group at 10 J/cm(2) (L10), and injured laser-treated group at 50 J/cm(2) (L50). Laser treatment started immediately after the surgery and it was performed for 15 sessions. An 808 nm laser, at 10 and 50 J/cm(2), was used. To evaluate the effects of LLLT, the qualitative and semi-quantitative histological, morphometric, and immunohistochemistry analysis were performed. Initial signs of tissue degradation were observed in CG. Interestingly, laser-treated animals presented a better tissue organization, especially at the fluence of 10 J/cm(2). Furthermore, laser phototherapy was able of modulating some of the aspects related to the degenerative process, such as the prevention of proteoglycans loss and the increase in cartilage area. However, LLLT was not able of modulating chondrocytes proliferation and the immunoexpression of markers related to inflammatory process (IL-1 and MMP-13). This study showed that 808 nm laser, at both fluences, prevented features related to the articular degenerative process in the knees of rats after ACLT.

Biocompatibility of a porous alumina ceramic scaffold coated with hydroxyapatite and bioglass.

This study aimed to evaluate the osteointegration and genotoxic potential of a bioactive scaffold, composed of alumina and coated with hydroxyapatite and bioglass, after their implantation in tibias of rats. For this purpose, Wistar rats underwent surgery to induce a tibial bone defect, which was filled with the bioactive scaffolds. Histology analysis (descriptive and morphometry) of the bone tissue and the single-cell gel assay (comet) in multiple organs (blood, liver, and kidney) were used to reach this aim after a period of 30, 60, 90, and 180 days of material implantation. The main findings showed that the incorporation of hydroxyapatite and bioglass in the alumina scaffolds produced a suitable environment for bone ingrowth in the tibial defects and did not demonstrate any genotoxicity in the organs evaluated in all experimental periods. These results clearly indicate that the bioactive scaffolds used in this study present osteogenic potential and still exhibit local and systemic biocompatibility. These findings are promising once they convey important information about the behavior of this novel biomaterial in biological system and highlight its possible clinical application.

Effects of phototherapy on cartilage structure and inflammatory markers in an experimental model of osteoarthritis.

The aim of this study was to evaluate the effects of laser phototherapy on the degenerative modifications on the articular cartilage after the anterior cruciate ligament transection (ACLT) in the knee of rats. Eighty male rats (Wistar) were distributed into four groups: intact control group (IG), injured control group (CG), injured laser treated group at 10 J/cm(2) (L10), and injured laser treated group at 50 J/cm(2) (L50). Animals were distributed into two subgroups, sacrificed in 5 and 8 weeks postsurgery. The ACLT was used to induce knee osteoarthritis in rats. After 2 weeks postsurgery, laser phototherapy initiated and it was performed for 15 and 30 sessions. The histological findings revealed that laser irradiation, especially at 10 J/cm(2), modulated the progression of the degenerative process, showing a better cartilage structure and lower number of condrocytes compared to the other groups. Laser phototherapy was not able to decrease the degenerative process measured by Mankin score and prevent the increase of cartilage thickness related to the degenerative process. Moreover, it did not have any effect in the biomodulation of the expression of markers IL1ß, tumor necrosis factor-α, and metalloprotein-13. Furthermore, laser irradiated animals, at 50 J/cm(2) showed a lower amount of collagen type 1.

Histopathological, cytotoxicity and genotoxicity evaluation of Biosilicate® glass-ceramic scaffolds.

This study evaluated the biocompatibility of Biosilicate® scaffolds by means of histopathological, cytotoxicity, and genotoxicity analysis. The histopathologic analysis of the biomaterial was performed using 65 male rats, distributed into the groups: control and Biosilicate®, evaluated at 7, 15, 30, 45, and 60 days after implantation. The cytotoxicity analysis was performed by the methyl thiazolyl tetrazolium (MTT) assay, with various concentrations of extracts from the biomaterial in culture of osteoblasts and fibroblasts after 24, 72, and 120 h. The genotoxicity analysis (comet assay) was performed in osteoblasts and fibroblasts after contact with the biomaterial during 24, 72, and 96 h. In the histopathology analysis, we observed a foreign body reaction, characterized by the presence of granulation tissue after 7 days of implantation of the biomaterial, and fibrosis connective tissue and multinucleated giant cells for longer periods. In the cytotoxicity analysis, extracts from the biomaterial did not inhibit the proliferation of osteoblasts and fibroblasts, and relatively low concentrations (12.5% and 25%) stimulated the proliferation of both cell types after 72 and 120 h. The analysis of genotoxicity showed that Biosilicate® did not induce DNA damage in both lineages tested in all periods. The results showed that the Biosilicate® scaffolds present in vivo and in vitro biocompatibility.

Comparação dos efeitos do laser de baixa potência e do ultrassom de baixa intensidade associado ao Biosilicato® no processo de reparo ósseo em tíbias de ratos / Comparative study of the effects of low-level laser and low-intensity ultrasound associated with Biosilicate® on the process of bone repair in the rat tibia

OBJETIVO: Verificar os efeitos da associação do Biosilicato® com o US e com o LLLT no processo de consolidação óssea em ratos, a partir da análise biomecânica e histológica. MÉTODOS: Foram utilizados 40 ratos machos distribuídos em quatro grupos (n = 10): grupo controle fratura sem tratamento (GCF); grupo tratado com Biosilicato® (GB); grupo tratado com Biosilicato® + laser (GBL); grupo tratado com Biosilicato® + US (GBUS). RESULTADOS: A análise biomecânica não apresentou diferença estatisticamente significativa nos grupos após o período experimental de 14 dias. Na análise morfométrica, o grupo controle apresentou presença moderada de tecido ósseo neoformado no interior dos defeitos e o grupo tratado com Biosilicato® apresentou resultados semelhantes. No entanto, foi observado o potencial osteogênico do biomaterial, uma vez que houve grande presença de células e tecido ósseo ao redor das partículas. Interessantemente, os grupos Biosilicato® associado ao laser terapêutico e ao US demonstraram quantidades menores de deposição de tecido ósseo quando comparados aos grupos controle fratura e Biosilicato®. CONCLUSÃO: A partir dos dados deste estudo podemos concluir que o Biosilicato® foi capaz de acelerar e potencializar a recuperação óssea, através da modulação do processo inflamatório e da estimulação da formação de tecido ósseo novo. No entanto, quando a LLLT ou o US foram associados, não foram encontrados resultados positivos.

OBJECTIVE: Verify the effects of the association between Biosilicate® and ultrasound and, Biosilicate® and laser in bone consolidation process of rats, through the biomechanical and histological analysis. METHODS: Forthy male rats were used. The animals were randomized into four groups (n=10): control group fracture no treated (CGF); group treated with Biosilicate® (BG); group treated with Biosilicate® and laser (BLG); group treated with Biosilicate® and ultrasound (BUG). RESULTS: The biomechanical analysis showed no significant difference among any groups after 14 days post-surgery. In the morphometric analysis, the control group showed moderate presence of new formed bone tissue inside the defects areas and the Biosilicate® group showed similar results. Despite those facts, the biomaterial osteogenic potential was demonstrated by the great amount of cells and bone tissue around the particles. Curiously, the Biosilicate® plus laser or ultrasound groups showed lower amounts of bone tissue deposition when compared with control fracture and Biosilicate® groups. CONCLUSION: The data from this study can conclude that Biosilicate® was able to accelerate and optimized the bone consolidation, through the modulation of the inflammatory process and the stimulation of new bone formation. However, when resources were associated, there are no positive results.

COMPARATIVE STUDY OF THE EFFECTS OF LOW-LEVEL LASER AND LOW-INTENSITY ULTRASOUND ASSOCIATED WITH BIOSILICATE(®) ON THE PROCESS OF BONE REPAIR IN THE RAT TIBIA.

OBJECTIVE: Verify the effects of the association between Biosilicate® and ultrasound and, Biosilicate® and laser in bone consolidation process of rats, through the biomechanical and histological analysis. METHODS: Forthy male rats were used. The animals were randomized into four groups (n=10): control group fracture no treated (CGF); group treated with Biosilicate® (BG); group treated with Biosilicate® and laser (BLG); group treated with Biosilicate® and ultrasound (BUG). RESULTS: The biomechanical analysis showed no significant difference among any groups after 14 days post-surgery. In the morphometric analysis, the control group showed moderate presence of new formed bone tissue inside the defects areas and the Biosilicate® group showed similar results. Despite those facts, the biomaterial osteogenic potential was demonstrated by the great amount of cells and bone tissue around the particles. Curiously, the Biosilicate® plus laser or ultrasound groups showed lower amounts of bone tissue deposition when compared with control fracture and Biosilicate® groups. CONCLUSION: The data from this study can conclude that Biosilicate® was able to accelerate and optimized the bone consolidation, through the modulation of the inflammatory process and the stimulation of new bone formation. However, when resources were associated, there are no positive results.

Comparison of the effects of low-level laser therapy and low-intensity pulsed ultrasound on the process of bone repair in the rat tibia.

BACKGROUND: Electrophysical agents such as Ultrasound (US) and low-level laser therapy (LLLT) have been increasingly used in physical therapy practice. Studies suggest that these devices are able to stimulate osteoblast proliferation and osteogenesis at the fracture site, resulting in a greater deposition of bone mass and speeding up the consolidation process. OBJECTIVE: The aim of this study was to analyze the effects of US and LLLT on the bone healing process, through biomechanical and histological analysis of the bone callus. METHODS: A total of 30 rats were randomly allocated into three groups: control group fracture without treatment (GC); fracture group treated with pulsed US, burst 1.5 MHz, 200 us, 1 KHz, 30 mW/cm² (GUS) and fracture group treated with laser 830 nm, 100 mW, 120 J/cm² (GL). Bone defects were performed with a circular drill of 2mm in diameter in the animal's tibias. The treatments were carried out after surgery consisting of 7 applications every 48 hours. After 14 days the animals were sacrificed and the tibias were removed to perform the analysis, being the right tibia designated for biomechanical analysis, while the left tibia for histological analysis. RESULTS: The biomechanical analysis showed no statistically significant difference between biomechanical properties of the CG, CL and GUS. In morphometric analysis, both GUS and GL showed a significantly higher woven bone tissue area compared to the control group. However, when the two treatment modalities were compared, there were no statistical differences between them. CONCLUSION: Both devices used in this study were able to accelerate the bone healing process in rats.

Effect of low-level laser therapy (660 nm) on the healing of second-degree skin burns in rats.

The aim of this study was to investigate the effects of 660 nm laser on the healing of burn wounds made on the backs of rats. Thirty-two Wistar male rats were used. The animals were randomly distributed into 2 groups of 16 animals each: control group (burned rats without treatment) and laser-treated group (burned rats treated with laser therapy). Each group was divided into two different subgroups, euthanized in different periods (subgroup A: 7 days post-surgery and subgroup B: 14 days post-surgery). Histopathological analysis revealed a significant decrease in the necrotic area in the laser-treated group compared to the controls at days 7 and 14 post-injury. COX-2 positive cells were found in a strong pattern in the group submitted to laser therapy after 7 days. Regarding VEGF immunomarker, a significant VEGF immunoexpression was detected in the laser-exposed group after 14 days when compared to the negative control group. Taken together, our results demonstrate that laser therapy is able to promote skin repair of burned rats as a result of decreasing necrotic area and an up-regulation of COX-2 and VEGF immunoexpression.

Comparação dos efeitos do laser de baixa potência e do ultrassom de baixa intensidade no processo de reparo ósseo em tíbia de rato / Comparison of the effects of low-level laser therapy and low-intensity pulsed ultrasound on the process of bone repair in the rat tibia

CONTEXTUALIZAÇÃO: Recursos eletrofísicos, como o ultrassom (US) e a terapia laser de baixa potência (LLLT), vêm sendo cada vez mais utilizados na prática fisioterapêutica. Estudos sugerem que esses recursos são capazes de estimular a proliferação de osteoblastos e a osteogênese no local da fratura, promovendo maior deposição de massa óssea e acelerando o processo de consolidação. OBJETIVO: Analisar os efeitos do US e da LLLT no processo de consolidação óssea por meio das análises biomecânica e histológica do calo ósseo. MÉTODOS: Foram utilizados 30 ratos machos, distribuídos aleatoriamente em três grupos: grupo controle fratura, sem tratamento (GC); grupo fratura tratado com US pulsado com burst de 1,5 MHz, 200us, 1KHz, 30 mW/cm² (GUS) e grupo fratura tratado com laser 830nm, 100mW, 120J/cm² (GL). Foram realizados defeitos ósseos circulares com broca de 2 mm de diâmetro nas tíbias dos animais. Os tratamentos foram realizados a cada 48 horas, totalizando sete aplicações e, no 14º dia, os animais foram sacrificados. A tíbia direita foi designada para análise biomecânica, enquanto a esquerda, para análise histológica. RESULTADOS: A análise biomecânica não mostrou diferença estatisticamente significativa entre as propriedades biomecânicas do GC, GL e GUS. Na análise morfométrica, tanto GUS quanto GL apresentaram área de osso neoformado estatisticamente maior em relação ao GC. No entanto, quando as duas modalidades de tratamento foram comparadas, não foram encontradas diferenças estatísticas entre elas. CONCLUSÃO: Ambos os recursos utilizados neste estudo foram capazes de acelerar o processo de reparo ósseo em ratos.

BACKGROUND: Electrophysical agents such as Ultrasound (US) and low-level laser therapy (LLLT) have been increasingly used in physical therapy practice. Studies suggest that these devices are able to stimulate osteoblast proliferation and osteogenesis at the fracture site, resulting in a greater deposition of bone mass and speeding up the consolidation process. OBJECTIVE: The aim of this study was to analyze the effects of US and LLLT on the bone healing process, through biomechanical and histological analysis of the bone callus. METHODS: A total of 30 rats were randomly allocated into three groups: control group fracture without treatment (GC); fracture group treated with pulsed US, burst 1.5 MHz, 200us, 1KHz, 30 mW/cm² (GUS) and fracture group treated with laser 830nm, 100mW, 120J/cm² (GL). Bone defects were performed with a circular drill of 2mm in diameter in the animal's tibias. The treatments were carried out after surgery consisting of 7 applications every 48 hours. After 14 days the animals were sacrificed and the tibias were removed to perform the analysis, being the right tibia designated for biomechanical analysis, while the left tibia for histological analysis. RESULTS: The biomechanical analysis showed no statistically significant difference between biomechanical properties of the CG, CL and GUS. In morphometric analysis, both GUS and GL showed a significantly higher woven bone tissue area compared to the control group. However, when the two treatment modalities were compared, there were no statistical differences between them. CONCLUSION: Both devices used in this study were able to accelerate the bone healing process in rats.

Low-level laser therapy induces differential expression of osteogenic genes during bone repair in rats.

OBJECTIVES: The aim of this study was to measure the temporal pattern of the expression of osteogenic genes after low-level laser therapy during the process of bone healing. We used quantitative real-time polymerase chain reaction (qPCR) along with histology to assess gene expression following laser irradiation on created bone defects in tibias of rats. MATERIAL AND METHODS: The animals were randomly distributed into two groups: control or laser-irradiated group. Noncritical size bone defects were surgically created at the upper third of the tibia. Laser irradiation started 24 h post-surgery and was performed for 3, 6, and 12 sessions, with an interval of 48 h. A 830 nm laser, 50 J/cm(2), 30 mW, was used. On days 7, 13, and 25 post-injury, rats were sacrificed individually by carbon dioxide asphyxia. The tibias were removed for analysis. RESULTS: The histological results revealed intense new bone formation surrounded by highly vascularized connective tissue presenting slight osteogenic activity, with primary bone deposition in the group exposed to laser in the intermediary (13 days) and late stages of repair (25 days). The quantitative real-time PCR showed that laser irradiation produced an upregulation of BMP-4 at day 13 post-surgery and an upregulation of BMP4, ALP, and Runx 2 at day 25 after surgery. CONCLUSION: Our results indicate that laser therapy improves bone repair in rats as depicted by differential histopathological and osteogenic genes expression, mainly at the late stages of recovery.

Comparative effects of low-intensity pulsed ultrasound and low-level laser therapy on injured skeletal muscle.

OBJECTIVE: The main purpose of this study was to compare the effects of low-intensity pulsed ultrasound (US) and low-level laser therapy (LLLT) on injured skeletal muscle after cryolesion by means of histopathological analysis and immunohistochemistry for cyclo-oxygenase-2 (COX-2). BACKGROUND AND METHODS: Thirty-five male Wistar rats were randomly distributed into four groups: intact control group with uninjured and untreated animals; injured control group with muscle injury and no treatment; LLLT-treated group with muscle injury treated with 830-nm laser; and US-treated group with muscle injury treated with US. Treatments started 24 h postsurgery and were performed during six sessions. RESULTS: LLLT-treated animals presented minor degenerative changes of muscle tissue. Exposure to US reduced tissue injuries induced by cryolesion, but less effectively than LLLT. A large number of COX-2 positive cells were found in untreated injured rats, whereas COX-2 immunoexpression was lower in both LLLT- and US-treated groups. CONCLUSION: This study revealed that both LLLT and US therapies have positive effects on muscle metabolism after an injury in rats, but LLLT seems to produce a better response.

Low-intensity pulsed ultrasound produced an increase of osteogenic genes expression during the process of bone healing in rats.

The aim of this study was to measure the temporal expression of osteogenic genes during the process of bone healing in low-intensity pulsed ultrasound (LIPUS) treated bone defects by means of histopathologic and real-time polymerase chain reaction (PCR) analysis. Animals were randomly distributed into two groups (n = 30): control group (bone defect without treatment) and LIPUS treated (bone defect treated with LIPUS). On days 7, 13 and 25 postinjury, 10 rats per group were sacrificed. Rats were treated with a 30 mW/cm(2) LIPUS. The results pointed out intense new bone formation surrounded by highly vascularized connective tissue presenting a slight osteogenic activity, with primary bone deposition was observed in the group exposed to LIPUS in the intermediary (13 days) and late stages of repair (25 days) in the treated animals. In addition, quantitative real-time polymerase chain reaction (RT-qPCR) showed an upregulation of bone morphogenetic protein 4 (BMP4), osteocalcin and Runx2 genes 7 days after the surgery. In the intermediary period, there was no increase in the expression. The expression of alkaline phosphatase, BMP4 and Runx2 was significantly increased at the last period. Our results indicate that LIPUS therapy improves bone repair in rats and upregulated osteogenic genes, mainly at the late stages of recovery.

Comparative study of the effects of low-intensity pulsed ultrasound and low-level laser therapy on bone defects in tibias of rats.

The aim of this study was to investigate and to compare the effects of low intensity ultra-sound (LIPUS) and low-level laser therapy (LLLT) during the process of bone healing by means of histopathological and morphometric analysis. The animals were randomly distributed into three groups of 30 animals each: the control group (bone defect without treatment); the laser-treated group: (bone defect treated with laser), and the LIPUS-treated (bone defect treated with ultrasound). Each group was further divided into three different subgroups (n = 10) and on days 7, 13, and 25 post-injury, rats were killed with an intra-peritoneal injection of general anesthetic. The rats were treated with a 30-mW/cm(2) low-intensity pulsed ultrasound and a 830-nm laser at 50 J/cm(2). The results showed intense new bone formation surrounded by highly vascularized connective tissue presenting a slight osteogenic activity, with primary bone deposition being observed in the group exposed to laser in the intermediary (13 days) and late stages of repair (25 days). This was confirmed by morphometric analysis in which significant statistical differences (p < 0.05) were noticed when compared to the control. No remarkable differences were noticed in the specimens treated with ultrasound with regard to the amount of newly formed bone in comparison to the control group. Taken together, our results indicate that laser therapy improves bone repair in rats as depicted by histopathological and morphometric analysis, mainly at the late stages of recovery. Moreover, it seems that this therapy was more effective than US to accelerate bone healing.

Efeitos dos recursos eletrofísicos na osteoporose: uma revisão da literatura / Effects of electrophysical resources in osteoporosis: a review of the literature

OBJETIVO: Fazer uma revisão bibliográfica a respeito dos efeitos dos principais recursos eletrofísicos utilizados na aceleração do metabolismo ósseo e no tratamento da osteoporose. ANTECEDENTES: A Organização Mundial da Saúde (OMS) define a osteoporose como doença esquelética sistêmica caracterizada por diminuição da massa óssea e deterioração microarquitetural do tecido ósseo, com consequente aumento da fragilidade óssea e susceptibilidade à fratura. Vários tratamentos medicamentosos e não medicamentosos vêm sendo desenvolvidos na tentativa de aumentar a massa óssea e prevenir a osteoporose. Dentro desse contexto, os recursos eletrofísicos vêm tendo um papel de destaque, como recursos que apresentam um potencial osteogênico, capazes de estimular a proliferação de osteoblastos e biomodular o metabolismo ósseo. ESTRATÉGIA DE PESQUISA: Foram consultadas as bases de dados: The Cochrane Library, MEDLINE, Embase, LILACS, SciELO, referências dos artigos identificados, e contato com especialisas em laser, entre os anos de 1983 e 2009. CRITÉRIOS DE SELEÇÃO: Foram incluídos estudos experimentais e ensaios clínicos randomizados que avaliaram os efeitos dos recursos eletrofísicos na osteoporose. RECOMPILAÇÃO E ANÁLISE DE DADOS: Dois revisores selecionaram independentemente os estudos, avaliaram sua qualidade metodológica dos estudos e coletaram os dados. RESULTADOS: Todos os recursos eletrofísicos citados neste artigo se mostraram eficazes na estimulação do metabolismo ósseo. No entanto, a grande maioria dos estudos realizados evidenciam esses efeitos através de estudos in vitro e estudos experimentais com cobaias. Cabe ressaltar que trabalhos como esses são raros em seres humanos. Baseado nos achados desta revisão pode ser sugerido que os recursos eletrofísicios como o laser terapêutico, o ultrassom, campos eletromagnéticos e plataformas vibratórias são recursos que tem um potencial osteogênico entretanto mais estudos são necessários para definir os efeitos dos mesmos em humanos, bem como, protocolos mais eficazes de tratamento. CONCLUSÃO: A partir deste levantamento bibliográfico, fica evidente que os recursos eletrofísicos apresentam um grande potencial osteogênico, porém, a maior parte dos estudos é in vitro. São necessários mais estudos in vivo, definindo, assim, melhores parâmetros e doses, para que sejam utilizados no tratamento da osteoporose.

OBJECTIVE: The aim of this article was to provide a literature review regarding the impact of the main eletrophysical resources used on the acceleration of bone metabolism and on the osteoporosis treatment. DEFINITION: The OMS defines osteoporosis as a Sistemic esqueletical disease characterized for diminished bone mass and for deterioration of the bone mass microarchitecture, increasing the bone fragility and susceptibility to fracture. Many drug or non-drug treatments are being developed as an attempt to increase the bone mass, and prevent osteoporosis. Within this context, the eletrophysical resources is having a prominence paper, as a resource which presents a osteogenic potencial, capable of stimulating the proliferation of osteoblasts and biomodulate the bone metabolism. RESEARCH STRATEGIES: The data base consulted were: The Cochrane Library, MEDLINE, Embase, LILACS, SciELO, references of indentified articles and contact with laser's especialists, between 1983 and 2009. SELECTION CRITERIA: Were included experimental study and randomized clinical tests on the effects of eletrophysical resources on osteoporosis. RECOMPILATION AND DATA ANALISIS: Two reviewers independently selected the studies, assessed their methodological quality and collected the data. RESULTS: All the eletrophysical resources quoted on this article were effective in stimulation of bone metabolism. However, most of the studies show these effects through in vitro studies and experimental studies with animals. It is important to say that experiments like these are rare in human beings. Based on the findings of this review, it may be suggested that the eletrophysical resources like lasertherapy, ultra-sound, electromagnetic fields and vibration are resources that has osteogenic potencial, but more studies are needed to define the effects of it in humans, as well as more effective treatment protocols. CONCLUSION: With this literature review it is clear that eletrophysical resources have high osteogenic potential, but most of the studies are in vitro. It is needed more studies in vivo, defining therefore, better parameters and doses to be used in the treatment of osteoporosis.

Low level laser therapy does not modulate the outcomes of a highly bioactive glass-ceramic (Biosilicate) on bone consolidation in rats.

The main purpose of the present work was to evaluate if low level laser therapy (LLLT) can improve the effects of novel fully-crystallized glass-ceramic (Biosilicate) on bone consolidation in tibial defects of rats. Forty male Wistar rats with tibial bone defects were used. Animals were divided into four groups: group bone defect control (CG); group bone defect filled with Biosilicate (BG); group bone defect filled with Biosilicate, irradiated with LLLT, at 60 J cm(-2) (BG 60) and group bone defect filled with Biosilicate, irradiated with LLLT, at 120 J cm(-2) (BG 120). A low-energy GaAlAs 830 nm, CW, 0.6 mm beam diameter, 100 W cm(-2), 60 and 120 J cm(-2) was used in this study. Laser irradiation was initiated immediately after the surgery procedure and it was performed every 48 h for 14 days. Fourteen days post-surgery, the three-point bending test revealed that the structural stiffness of the groups CG and BG was higher than the values of the groups BG60 and BG120. Morphometric analysis revealed no differences between the control group and the Biosilcate group. Interestingly, the groups treated with Biosilicate and laser (BG 60 and BG120) showed statistically significant lower values of newly formed bone in the area of the defect when compared to negative control (CG) and bone defect group filled with Biosilicate (CB). Our findings suggest that although Biosilicate exerts some osteogenic activity during bone repair, laser therapy is not able to modulate this process.