Carbon fiber felt scaffold from Brazilian textile PAN fiber for regeneration of critical size bone defects in rats: A histomorphometric and microCT study.

The objective of the present study was to evaluate the carbon fiber obtained from textile PAN fiber, in its different forms, as a potential scaffolds synthetic bone. Thirty-four adult rats were used (Rattus norvegicus, albinus variation), two critical sized bone defects were made that were 5 mm in diameter. Twenty-four animals were randomly divided into four groups: control (C)-bone defect + blood clot, non-activated carbon fiber felt (NACFF)-bone defect + NACFF, activated carbon fiber felt (ACFF)-bone defect + ACFF, and silver activated carbon fiber felt (Ag-ACFF)-bone defect + Ag-ACFF, and was observed by 15 and 60 days for histomorphometric, three-dimensional computerized microtomography (microCT) and mineral apposition analysis. On histomorphometric and microCT analyses, NACFF were associated with higher proportion of neoformed bone and maintenance of bone structure. On fluorochrome bone label, there was no differences between the groups. NACFF has shown to be a promising synthetic material as a scaffold for bone regeneration.

Carbon fiber: Characterization and evaluation of the inflammatory response and toxicity in rats.

This study aimed to evaluate the Carbon Fiber obtained from PAN textile and cotton fiber in their different forms of presentation: non-activated carbon fiber felt (NACFF), activated carbon fiber felt (ACFF), silver activated carbon fiber felt (Ag-ACFF), and activated carbon fiber tissue (ACFT), to obtain scaffolds as a potential material with properties related to the synthetic bone graft. Characterization tests performed: surface wettability, traction, swelling, and in vivo tests: evaluation of the inflammatory response by implanting the materials in the subcutaneous tissue of 14 Wistar rats, evaluation of collagen fibers by picrosirius red staining and assessment of toxicity in the following organs: heart, spleen, liver, and kidney. In the wettability test, NACFF and ACFT were hydrophobic (θ124° and 114°), ACFF and Ag-ACFF were hydrophilic. For maximum stress, ACFF was more resistant (2.983 ± 1.059) p < .05. In the swelling test, the Ag-ACFF and ACFF groups showed the highest absorption percentage for the PBS solution and distilled water (p < .001). The organs showed no signs of acute systemic toxicity. The implant regions showed mild to moderate inflammatory infiltrate at 7 and 21 days. Only the ACFT group did not show the maturation of type I collagen fibers in 21 days. Through the conducted analyses, the ACFT shows little potential to be indicated as a possible scaffold. Therefore NACFF, ACFF, and Ag-ACFF have the potential to be considered scaffolds due to the following characteristics presented: good absorption rate, hydrophilicity, and non-toxic.

Systemic scleroderma: imaging findings of diagnosis and clinical management of temporomandibular joint disorders / Esclerodermia sistêmica: diagnóstico por achados imaginológicos e manejo clínico das disfunções temporomandibulares

Scleroderma, an autoimmune disease, directly affects the production of collagen in the connective tissue. In its systemic form, the disease causes oral manifestations such as: limited mouth opening, xerostomia, periodontal disease, thickening of the periodontal ligament and bone resorption of the mandible. This case report aims to draw attention to the difficulties encountered in providing dental care to patients with scleroderma and also to highlight the imaging findings, with emphasis on the temporomandibular joints, which are of interest to dentists about the disease. In the present case, the patient presented bilateral condylar erosion, in addition to disc displacement without reduction. Due to the systemic condition of the patient, it was decided to make an individualized occlusal splint. The limitation of mouth opening is a limiting factor for the manufacture of prostheses and plates, which is why partial prostheses are indicated and are easily removed by the patient. The decisions taken have a great impact on the health and quality of life of patients in these conditions, so there is a need for multidisciplinary involvement in order to arrive at the best treatment plan. After five years of using the stabilizing plate overnight, the patient reports greater comfort and muscle relaxation upon waking up (AU)

Esclerodermia, uma doença autoimune, afeta diretamente a produção de colágeno do tecido conjuntivo. Na forma sistêmica, a doença causa manifestações bucais, como: limitação de abertura bucal, xerostomia, doença periodontal, espessamento do ligamento periodontal e reabsorção da mandíbula. Este relato de caso tem por objetivo chamar atenção para as dificuldades encontradas ao promover atendimento odontológico para pacientes com esclerodermia e também destacar os achados imaginológicos, com ênfase na articulação temporomandibular, que são da doença e de interessa ao cirurgião-dentista. No presente caso, a paciente apresentava erosão condilar bilateral, com deslocamento de disco sem redução. Devido à condição sistêmica da paciente, foi decidido confeccionar uma placa oclusal individualizada. A limitação de abertura bucal é um fator limitante para confecção de próteses e placas, por isso próteses parciais são indicadas, além de serem de fácil remoção pelo paciente. As decisões tomadas tem grande impacto na saúde e qualidade de vida de pacientes nessas condições, deste modo é necessário uma equipe multidisciplinar envolvidas para chegar no melhor plano de tratamento. Após cinco anos fazendo uso da placa estabilizadora durante a noite, a paciente relata maior conforto e relaxamento muscular ao acordar (AU)

Fibra de carbono ativada: avaliação das interações biológicas in vitro / Activated carbon fiber: evaluation of biological interactions in vitro

Devido a constante necessidade de desenvolver materiais biocompatíveis com propriedades osteocondutores e osteoindutoras, a presente tese conta com o desenvolvimento de dois estudos in vitro com fibra de carbono obtida a partir de fibra PAN têxtil, incorporada com diferentes íons de metais, na osteogênese com vistas à compreensão das necessidades da engenharia tecidual no desenvolvimento desse biomaterial com adequadas propriedades biológicas. As células foram obtidas dos fêmures de 09 ratos machos adultos (Wistar) pesando 300g, com 90 dias.Estudo 1: A partir da preparação da fibras foram obtidos corpos de prova de 4 mm de diâmetro e 2 mm de altura, dos seguintes grupos: fibra de carbono não ativada (FCNA), fibra carbono ativada (FCA) e fibra carbono ativada com prata (FCAAg). Após plaqueamento (n=5) em meio suplementado (MTS) e meio suplementado osteogênico (MTSO) foram analisados: viabilidade celular, conteúdo de proteína total (PT), atividade de fosfatase alcalina (ALP), interaçãocelular e formação de nódulos de mineralização. Foi avaliada a formação de biofilme nos corpos de prova, utilizando cepas de S. aureus, P. aeruginosa e E. coli. Na viabilidade celular, houve diferença estatística entre grupo controle celular (C) e FCA-MTS, FCAAg-MTS e FCAAg-MTSO. Em PT, não houvediferença, na ALP houve diferença entre C-MTS e as fibras, C-MTSO se mostrou semelhante. Em nódulos, houve diferença entre C-MTS e C-MTSO e as fibras do MTSO. Houve redução de formação de biofilme do S. aureus na FCAAg.Estudo 2: Foram obtidos corpos de prova da mesma dimensão do estudo 1 (n=5) dos seguintes grupos: fibra carbono ativada com prata (FCAAg), fibra carbono ativada com ouro (FCAAu), fibra carbono ativada com cobre (FCACu), fibra carbono ativada com paládio (FCAPd) e fibra carbono ativada com platina (FCAPt). Foram quantificadas a proliferação celular, viabilidade celular, formação de nódulos de mineralização, conteúdo de PT e ALP. Todas as amostras mostraram-se semelhantes quanto a proliferação celular, com exceção do grupo FCAAg comparado ao grupo controle (C). Sobre viabilidade celular, C obteve maior viabilidade que os outros grupos, e FCA obteve maior taxa que os grupos FCAAg, FCACu, FCAPt, sendo semelhante aos grupos FCAAu e FCAPd. Já os grupos FCAAu e FCAPd apresentaram diferença aos grupos FCAAg e FCACu. Na análise de expressão de PT apenas houve diferença entre FCA e FCAAu, sendo FCAAu com menor expressão de produção de PT. Na avaliação da ALP os grupos FCAAg e FACu mostraram diferença estatística e inferior com os grupos C, FCAAu, FCAPd e FCAPt, além disso, o grupo FCA mostrou menor taxa que C.Conclusões: As fibras utilizadas de base para a incorporação dos íons demonstraram grande potencial para uso como scaffold para reparação óssea, isso porque em ambos os estudos, na forma ativada e não ativada, as fibras apresentaram viabilidade celular e quantificação de cálcio satisfatórias. Sendo a versão não ativada mais econômica no que diz respeito ao tempo e custo de preparação. Mais estudos devem ser empregados a fim de assegurar sua segurança clínica em relação à citotoxicidade da incorporação de íons de ouro e paládio.(AU)

Due to the constant need to develop biocompatible materials with osteoconductive and osteoinductive properties, this thesis involves the development of two in vitro studies with carbon fiber obtained from textile PAN fiber, incorporated with different metal ions, in osteogenesis with a view to understanding the needs of tissue engineering in the development of this biomaterial with adequate biological properties. The cells were obtained from the femurs of 9 adult male rats (Wistar) weighing 300g, aged 90 days. Study 1: From the fiber preparation, specimens measuring 4 mm in diameter and 2 mm in height were obtained from the following groups: non-activated carbon fiber (FCNA), activated carbon fiber (FCA) and silver-activated carbon fiber (FCAAg). After plating (n=5) in supplemented medium (MTS) and supplemented osteogenic medium (MTSO), cell viability, total protein content (PT), alkaline phosphatase (ALP) activity, cell interaction and formation of mineralization nodules were analyzed. . Biofilm formation was evaluated in the specimens, using strains of S. aureus, P. aeruginosa and E. coli. In cell viability, there was a statistical difference between the cell control group (C) and FCAMTS, FCAAg-MTS and FCAAg-MTSO. In PT, there was no difference, in ALP there was a difference between C-MTS and fibers, C-MTSO was similar. In nodules, there was a difference between C-MTS and C-MTSO and MTSO fibers. There was a reduction in S. aureus biofilm formation on FCAAg. Study 2: Specimens of the same size as in study 1 (n=5) were obtained from the following groups: carbon fiber activated with silver (FCAAg), carbon fiber activated with gold (FCAAu), carbon fiber activated with copper (FCACu), palladium-activated carbon fiber (FCAPd) and platinum-activated carbon fiber (FCAPt). Cell proliferation, cell viability, formation of mineralization nodules, PT and ALP content were quantified. All samples were similar in terms of cell proliferation, with the exception of the FCAAg group compared to the control group (C). Regarding cell viability, C obtained higher viability than the other groups, and FCA obtained a higher rate than the FCAAg, FCACu, FCAPt groups, being similar to the FCAAu and FCAPd groups. The FCAAu and FCAPd groups showed differences to the FCAAg and FCACu groups. In the analysis of PT expression, there was only a difference between FCA and FCAAu, with FCAAu having lower expression of PT production. In the ALP assessment, the FCAAg and FACu groups showed a lower statistical difference compared to the C, FCAAu, FCAPd and FCAPt groups, in addition, the FCA group showed a lower rate than C. Conclusions: The fibers used as the basis for the incorporation of ions demonstrated great potential for use as a scaffold for bone repair, because in both studies, in activated and non-activated form, the fibers showed satisfactory cell viability and calcium quantification. The non-activated version is moreeconomical in terms of preparation time and cost. More studies must be carried out to ensure its clinical safety in relation to the cytotoxicity of the incorporation of gold and palladium ions. (AU)

Bone repair assessment of critical size defects in rats treated with mineralized bovine bone (Bio-Oss®) and photobiomodulation therapy: a histomorphometric and immunohistochemical study.

This study aimed to investigate the effects of administering photobiomodulation therapy (PBM) with bovine bone matrix on critical size defects in rats. Seventy-two adult male rats (albinus, Wistar), 90 days old, were used. Defect of 5 mm in diameter was made in their calvaria. The animals were divided into 4 groups: C-blood clot, B-Bio-Oss®, L-PBM, B+L-Bio-Oss®+PBM. Each group has been subdivided into 07, 30, and 60 days of observation. For PBM, a low GaAlAs energy of 660 nm was irradiated, total energy density of 45 J/cm2 . PBM was conducted in a trans-surgical form once only. For immunohistochemistry, a semi-quantitative analysis was made of expression of osteoprotegerin (OPG), nuclear kappa B-factor ligand receptor activator (RANKL), and tartrate-resistant acid phosphatase (TRAP). All histomorphometric data were statistically analyzed by ANOVA and Tukey test, significance level of 5%. The groups that showed the highest proportion of neoformation were L (0.39% ± 0.13) and C (0.37% ± 0.97), but groups B and B+L had larger defect size (C-1.75 mm2 ± 0.40, B-3.02 mm2 ± 0.63, L-2.45 mm2 ± 0.53, B+L-3.23 mm2 ± 1.01). In immunohistochemistry, groups B and B+L had higher immunostaining scores for OPG and RANKL at 60 days, and TRAP immunostaining increased in all groups at 30 days, but group L was the only one to present specimens with score 0. Although, at 60 days, groups L and C presented the highest proportion of bone neoformation, at 30 days group B+L had more than twice as much bone neoformation as group B, the choice of treatment application should depend on the aim of the treatment.

The Effect of Photobiomodulation Therapy in Different Doses on Bone Repair of Critical Size Defects in Rats: A Histomorphometric Study.

Introduction: Photobiomodulation therapy (PBM) appears to induce osteogenesis and stimulate fracture repair; because of its capacity, it is considered a promising treatment, but the characteristics of response to different radiation doses must be investigated through in vivo studies to establish their safety and effectiveness. Thus, this paper aims to analyze the effects of the PBM at different doses on the repair of critical bone defects through histological and histomorphometric analyses. Methods: Sixty 90-day-old adult rats (Rattus norvegicus, albinus, Wistar) weighing approximately 300 g were used. Critical bone defects of 5 mm in diameter were performed in their calvaria. The animals were randomly separated into 5 groups: C-Blood clot, L15-PBM 15J/cm2, L30-PBM 30 J/ cm2, L45-PBM 45 J/cm2, L60-PBM 60 J/cm2. Each group was subdivided according to observation periods of 30 and 60 days with 6 rats in each subgroup. Low-level gallium aluminum arsenide (GaAlAs) lasers were used at a 660 nm wavelength, 30 mW and 0.04 cm2 in area. The PBM was applied over 5 points; 4 points of application were distributed on the edges while one point of application was located in the center of the bone defect. PBM occurred right after the procedure. In 30 and 60 days, the animals were euthanized by anesthesia overdose and the analyses were performed. The data were analyzed statistically by the ANOVA, together with the Tukey test, whose significance level was 5%. Results: As regards the treatment factor, the highest percentage of bone neoformation was achieved by group L45-60. The group with the highest closure, despite not having a statistically significant difference with the other doses, was 45 J with only 0.49 mm between edges. Conclusion: Thus, the present study allowed concluding that the highest percentage of bone neoformation area was achieved at 45 J/cm2 in 60 days; that is, it was significantly effective in comparison with other doses.

Avaliação do reparo ósseo de defeitos de tamanho crítico tratados com matriz óssea mineralizada de osso bovino (Bio-Oss®) / Assessment of bone repair of critical size defects treated with bovine bone mineral matrix (BioOss®) and low-level laser therapy: histomorphometric and immunohistochemical study in rats

Este estudo teve como objetivo investigar os efeitos da terapia com laser de baixa intensidade (LLLT) associada ao Bio-Oss® em defeitos de tamanho crítico de ratos. Foram utilizados 72 ratos machos adultos (Rattus norvegicus, variação albinus, Wistar), com 90 dias de idade. Foram realizados defeitos ósseos na calvária com 5 mm de diâmetro. Os animais foram divididos em 4 grupos: C-Coágulo sanguíneo, B- Bio-Oss®, L- LLLT, B+L- Bio-Oss® + LLLT. Cada grupo foi subdividido de acordo com os períodos de observação de 07, 30 e 60 dias, com 6 ratos em cada subgrupo. Para LLLT uma baixa energia GaAlAs com comprimento de onda de 660 nm, foi aplicada em 5 pontos. Foram distribuídos 4 pontos de aplicação ao longo das bordas da ferida e um ponto de aplicação localizado na região central da ferida cirúrgica. A irradiação foi liberada por 12 segundos por ponto, com uma densidade total de energia de 45 J/cm2. A irradiação com laser ocorreu de forma transcirurgica em única aplicação imediatamente após o procedimento. Em 07, 30 e em 60 dias, 6 animais de cada grupo foram eutanasiados pela aplicação de anestesia geral em dose triplicada, e após os testes de sensibilidade os animais foram decapitados. Em seguida a calvária foi removida para análises histomorfométrica e imunohistoquímica. Todos os dados histomorfométricos foram submetidos a análise por ANOVA, complementado pelo teste de Tukey. O nível de significância foi de 5%. Os resultados da imunohistoquímica foram representados por scores e porcentagem. Os grupos que apresentaram maior proporção de neoformação foram os grupos L (0,39±0,13) e C (0,37±0,97), porém os grupos B e B+L tiveram maior tamanho de defeito (C-1,75±0,40, B-3,02±0,63, L-2,45±0,53, B+L-3,23±1,01). Na imunohistoquímica, aos 60 dias, os grupos B (score 4-34%) e B+L (B+L score 4­50%) apresentaram maior scores de imunomarcação para OPG e RANKL, aos 30 dias a porcentagem de imunomarcação para TRAP aumentou em todos os grupos, sendo o L o único a apresentar espécimes com score 0 (16%). Os grupos que apresentaram maior proporção de neoformação foram os grupos L e C, no entanto, os maiores valores relacionados ao volume ósseo foram encontrados nos grupos B e B+L.Todos os grupos apresentaram menores valores referente a distância entre as bordas de osso neoformado no interior do defeito ao final do experimento.Os grupos B e B+L apresentaram os maiores scores de imunomarcação para OPG, as imunomarcações para TRAP apareceram mais tardiamente no grupo L(AU)

This study aimed to investigate the effects of low-level laser therapy (LLLT) associated with Bio-Oss® on critical size defects in rats. 72 adult male rats (Rattus norvegicus, variation albinus, Wistar), 90 days old, were used. Bone defects were made in the calvaria with a diameter of 5 mm. The animals were divided into 4 groups: C-blood clot, B-Bio-Oss®, L-LLLT, B + L- Bio-Oss® + LLLT. Each group was subdivided according to the observation periods of 07, 30 and 60 days, with 6 rats in each subgroup. For LLLT a low GaAlAs energy with a wavelength of 660 nm was applied at 5 points. 4 points of application were distributed along the edges of the wound and one point of application located in the central region of the surgical wound. The irradiation was released for 12 seconds per point, with a total energy density of 45 J/cm2. Laser irradiation occurred in a trans-surgical form in a single application immediately after the procedure. At 07, 30 and 60 days, 6 animals from each group were euthanized by applying triple dose of general anesthesia, after the sensitivity tests the animals were beheaded. Then the calvaria was removed for histomorphometric and immunohistochemistry analysis. All histomorphometric data were analyzed statistically by ANOVA, complemented by the Tukey test. The level of significance was 5%. The results of immunohistochemistry were represented by scores and percentage. The groups that showed the highest proportion of neoformation were groups L (0,39±0,13) and C (0,37±0,97), but groups B and B + L had a larger defect size (C-1,75±0,40, B-3,02±0,63, L-2,45±0,53, B+L-3,23±1,01). In immunohistochemistry, at 60 days, groups B (score 4- 34%) and B + L (B+L score 4 - 50%) had higher immunostaining scores for OPG and RANKL, at 30 days the percentage of immunomarking for TRAP increased in all groups, group L was the only one to present specimens with a score 0 (16%). The groups with the highest proportion of neoformation were groups L and C, however, the highest values related to bone volume were found in groups B and B+L. All groups had lower values regarding the distance between the edges of newly formed bone inside the defect at the end of the experiment. Groups B and B+L had the highest immunostaining scores for OPG, immunomarkings for TRAP appear later in group L(AU)