RESUMO
Tuberous sclerosis complex (TSC) is a genetic disorder, frequently characterized by early dermatological manifestations. The recognition and adequate description of these dermatological manifestations are of utmost importance for early diagnosis, allowing for the implementation of therapeutic and preventive measures. Fibrous cephalic plaques (FCPs) are considered a major diagnostic criterion for TSC, as FCPs are the most specific skin lesions of TSC. The localization, consistency, color, and size of FCPs vary widely, which can cause diagnostic delay, especially in patients with atypical presentations. The present report describes a female TSC patient with a confirmed heterozygous pathogenic genotype, NG_005895.1 (TSC2_v001): c.2640-1G>T, who presented with uncommon large and bilateral FCPs causing bilateral ptosis and marked with hyperostosis of the diploe that generated an asymmetry of the brain parenchyma. Differential diagnoses considered initially in this patient due to the atypical FCPs are described.
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OBJECTIVE: Integra Dermal Regeneration Template (IDRT) (Integra LifeSciences, US) is a bioengineered dermal matrix that has been widely used in burn reconstruction since its first description. However, little is reported on its use in oncologic dermatological defects. Our objective was to evaluate reconstruction using IDRT on cutaneous tumour defects. METHOD: We conducted a two-year retrospective review of patients with skin tumours who had an excision surgery, followed by reconstruction with IDRT, as a mid-step towards a final autograft procedure: a split-thickness skin graft. The records of all patients at a single academic institution were queried from the electronic medical record using data obtained from the operating surgeon. RESULTS: We identified 13 patients with different tumour types and locations. The mean defect size was 105.92cm². The matrix take rate was 92.3% and average postoperative day for definite autograft was 20 days. Patients were followed for a period of up to 12 months. Of the patients, one had exposed bone without periosteum; another patient showed recurrence six months after matrix placement, requiring a new second two-stage IDRT-autograft procedure before radiation therapy. Patients reported complete satisfaction with the cosmetic, functional and oncological results. No cases of infection were encountered. CONCLUSION: IDRT is a valid option for the reconstruction of oncologic surgical defects of the skin and can be used in different anatomical locations. Specifically, it is an alternative to the reconstructive ladder when grafts and local flaps are not possible in those patients, and an option for patients who will eventually need adjuvant radiotherapy.
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Procedimentos de Cirurgia Plástica , Neoplasias Cutâneas , Pele Artificial , Sulfatos de Condroitina/uso terapêutico , Colágeno/uso terapêutico , Humanos , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Neoplasias Cutâneas/cirurgia , Transplante de Pele/métodosRESUMO
O reparo de defeitos ósseos críticos representa um grande desafio clínico, dentre as terapias adjuvantes que apresentam um potencial benefício na aceleração do reparo ósseo destaca-se o CEMP, o qual por meio da sua estimulação biofísica é capaz de modular parâmetros fisiológicos de diferenciação, proliferação e mineralização das células ósseas. Sendo assim, o presente estudo teve como objetivo avaliar o efeito de dois protocolos de terapia com CEMP na neoformação óssea em defeitos críticos nas calotas de ratos. Noventa e seis ratos machos adultos foram divididos aleatoriamente em 3 grupos experimentais GC: (n= 32), GT1h: (n= 32) e GT3h: (n= 32). Os animais foram submetidos à cirurgia para a confecção de defeito crítico na calota craniana e à terapia com CEMP seguindo os seguintes parâmetros fixos: 25 ciclos de -1 mTesla a + 1 mTesla em 200 microssegundos que se repetiram à taxa de 15 Hz. O tempo de duração da exposição ao CEMP nos grupos testes foram de 1 hora (GT1h) e de 3 horas (GT3h), ambos durante 5 dias por semana. Os animais foram submetidos à eutanásia nos períodos 14, 21, 45 e 60 dias. Os espécimes foram processados para análise histológica, histomorfométrica e para análises de textura e volume, obtidas por meio de TCFC. As análises histomorfométrica e de volume revelaram que não houve diferença estaticamente significante no reparo dos defeitos ósseos entre os grupos que receberam a terapia com CEMP e o GC. A análise de textura revelou que houve diferença estatisticamente significante entre os grupos somente para o parâmetro entropia, no qual o grupo GT1h apresentou um maior valor comparado ao GC, ambos no período de 21 dias. Conclusão: não foi possível neste estudo mostrar um potencial benefício da utilização do CEMP na cicatrização óssea do DOC na calota de ratos. Dessa forma, esta região deve ser melhor explorada em estudos futuros, assim como a busca pelos parâmetros ideais relacionados ao gerador do CEMP de forma a maximizar os efeitos no reparo ósseo. (AU)
The repair of critical bone defects represents a major clinical challenge, among the adjuvant therapies that have a potential benefit in accelerating bone repair, PEMF stands out, which through its biophysical stimulation can modulate physiological parameters of differentiation, proliferation and mineralization of bone cells. Therefore, the present study aimed to evaluate the effect of two protocols of therapy with PEMF on bone neoformation on calvaria critical defects in rats. Ninety-six adult male rats were randomly divided into 3 experimental groups CG: (n=32), GT1h: (n=32) and GT3h: (n=32). The animals were submitted to surgery for the creation of a critical defect in the skull and to therapy with PEMF following the following fixed parameters: 25 cycles of -1 mTesla to + 1 mTesla in 200 microseconds that were repeated at a rate of 15 Hz. The duration of exposure to PEMF in the test groups was 1 hour (GT1h) and 3 hours (GT3h), both for 5 days a week. The animals were euthanized at 14, 21, 45 and 60 days. The specimens were processed for histological, histomorphometric and texture and volume analysis, obtained by CBCT. Histomorphometric and volume analyzes revealed that there was no statistically significant difference in the repair of bone defects between both groups receiving PEMF therapy and GC. The texture analysis revealed that there was a statistically significant difference between the groups, except for the entropy parameter, in which the GT1h group presented a higher value compared to CG, both in the period of 21 days. Conclusion: it was not possible in this study to show a potential benefit of using PEMF on bone healing of calvaria critical defects. Therefore, this region should be better explored in future studies, as well as seeking the ideal parameters related to the PEMF generator in order to maximize effects on bone repair (AU)
Assuntos
Animais , Ratos , Osteogênese , Regeneração Óssea , Tomografia Computadorizada de Feixe Cônico , Crânio , Campos EletromagnéticosRESUMO
Objetivo: comparar a neoformação óssea em defeitos críticos confeccionados em calvárias de ratos utilizando duas apresentações de membranas de colágeno porcino, Bio-Gide® e Ossix Plus® para o recobrimento da loja cirúrgica criada. Material e Método: trinta e dois ratos machos (Rattus novergicus, Albinus, Wistar) foram divididos entre os grupos BG (membrana de colágeno porcino Bio-Gide®, n=16) e OS (membrana de colágeno porcino Ossix Plus®, n=16). Foram realizados defeitos críticos de 8mm de diâmetro nas calvárias dos animais e estes foram recobertos com as membranas colágenas BG ou OS. Aos 15, 30 e 60 dias os animais foram sacrificados por sobredose anestésica e as amostras coletadas foram submetidas à análise histomorfométrica (t=15, n=8; t=30, n=8 e t=60, n=8) e microtomográfica (t=60, n=8). A análise histomorfométrica foi realizada de forma qualitativa e quantitativa. Os dados histométricos quantitativos e os da análise microtomográfica foram submetidos à estatística (p< 0,05). Resultados: a análise histomorfométrica não apontou diferença no desempenho entre as membranas BG e OS nos períodos de 15, 30 e 60 dias (p> 0,05). Para os dados qualitativos e quantitativos, aos 60 dias pós-operatórios, foram encontradas quantidades consideráveis da membrana OS quando comparada a BG, bem como no parâmetro macroscópico. A análise microtomográfica evidenciou médias superiores para BV, BV/TV, Tb.Th e i.S (p< 0,05) para o grupo OS. Conclusão: a membrana Ossix Plus® apresentou qualidade superior de neoformação óssea, além de permanecer a longo prazo na região dos defeitos críticos produzidos(AU)
Objective: to compare bone neoformation in critical defects made in rat calvaria using two presentations of porcine collagen membranes, Bio-Gide® and Ossix Plus® for covering the surgical pocket created. Material and Method: thirty-two male rats (Rattus novergicus, Albinus, Wistar) were divided between BG (Bio-Gide® porcine collagen membrane, n=16) and OS (Ossix Plus® porcine collagen membrane, n= 16). Critical defects of 8 mm in diameter were made in the animals' calvaria and they were covered with BG or OS collagen membranes. At 15, 30 and 60 days the animals were sacrificed by anesthetic overdose and the samples collected were submitted to histomorphometric (t=15, n=8; t=30, n=8 and t=60, n=8) and microtomographic (t=60, n=8) analysis. The histomorphometric analysis was performed qualitatively. Quantitative histometric and microtomographic data were submitted to statistics (p< 0,05). Results: the histomorphometric analysis showed no difference in performance between the BG and OS membranes in the periods of 15, 30 and 60 days (p> 0.05). For qualitative and quantitative data, at 60 days postoperatively, considerable amounts of OS membrane were found when compared to BG, as well as in the macroscopic parameter. The microtomographic analysis showed higher means for BV, BV/TV, Tb.Th and i.S (p< 0.05) for the OS group. Conclusion: the Ossix Plus® membrane showed superior bone neoformation quality, in addition to remaining longterm in the region of the critical defects produced(AU)
Assuntos
Animais , Ratos , Regeneração Óssea , Transplante Ósseo , Osteogênese , Crânio , Ratos WistarRESUMO
Introdução: O osso bovino inorgânico é o enxerto mais utilizado na Odontologia, tendo como desvantagem longo tempo de integração ao leito receptor. Os bifosfonatos têm sido utilizados para modular a quantidade e a qualidade do osso regenerado e diminuir o tempo de integração do enxerto. Objetivo: Avaliar o efeito do bifosfonato alendronato de sódio (ALN) 0,5%, associado ou não ao osso bovino inorgânico, na reparação de defeitos ósseos. Material e método: Dois defeitos ósseos foram confeccionados na calvária de 12 coelhos, sendo a cavidade esquerda/experimental preenchida com: GI = osso bovino inorgânico (Bio-Oss®); GII = Bio-Oss® + ALN 0,5%; GIII = ALN 0,5%; e a cavidade direita por coágulo sanguíneo (controle). Os animais foram mortos aos 60 dias pós-operatórios. Por meio de análise histomorfométrica calculou-se o percentual de osso neoformado e remanescente do biomaterial em relação à área total do defeito. Resultado: Osso neoformado: GI = 38,16 ± 15,44%; GII = 55,77 ± 16,75%; GII I = 60,28 ± 11,45%. Controle = 45,11 ± 11,09%. Remanescente do enxerto: GI = 7,02 ± 5,36% e GII = 16,59 ± 9,56%. Não houve diferença quanto ao percentual de osso neoformado entre os grupos (ANOVA p = 0,15512; teste de Tukey F = 2,089). O percentual de remanescente do enxerto também foi estatisticamente semelhante entre os grupos GI e GII (teste de Tukey F = 5,019). Conclusão: O uso tópico da solução de ALN 0,5% isoladamente ou associado ao osso bovino liofilizado não alterou o percentual de neoformação óssea nem a degradação dos grânulos do enxerto.
Introduction: Inorganic bovine bone is the most used graft in dentistry, with the disadvantage of long integration time into the receptor bed. Bisphosphonates have been used to modulate the quantity and quality of regenerated bone and decrease graft integration time. Objective: To evaluate the effect of alendronate sodium bisphosphonate (ALN) 0.5%, associated or not with Inorganic bovine bone, in the repair of bone defects. Material and method Two bone defects were made in the calvaria of 12 rabbits, and the left/experimental cavity was filled with: GI = Inorganic bovine bone (Bio-Oss®); GII = Bio-Oss® + 0.5% ALN; GIII = 0.5% ALN; and the right cavity/blood clot control. The animals were killed at 60 days after surgery. Through histomorphometric analysis, the percentage of newly formed bone and remnant biomaterial relative to the total area of the defect was calculated. Result: Neoformed bone: GI = 38.16 ± 15.44%, GII = 55.77 ± 16.75%; GIII= 60.28 ± 11.45%; Control=45,11 ± 11,09%. Graft remnant: GI = 7.02 ± 5.36% and GII = 16.59 ± 9.56%. There was no difference in the percentage of newly formed bone between the groups (ANOVA p = 0.15512; Tukey's test F = 2.089). The percentage of graft remnant was also statistically similar between groups GI and GII (Tukey's test F = 5019). Conclusion: Topical use of 0.5% ALN solution alone or associated with lyophilized bovine bone did not change the percentage of bone neoformation, nor the degradation of graft granules.
Assuntos
Animais , Coelhos , Crânio , Osso e Ossos , Regeneração Óssea , Análise de Variância , Substitutos Ósseos , Alendronato , DifosfonatosRESUMO
In order to provide favorable conditions for bone regeneration, a lot of biomaterials have been developed and evaluated, worldwide. Composite biomaterials have gained notoriety, as they combine desirable properties of each isolated material. Thus, in this research, bone repair capacity of three developed formulations of ceramic scaffolds were evaluated histomorphometrically, after implantation. Scaffolds were based on wollastonite (W) andß-tricalcium phosphate (ß-TCP) composites in three different ratios (wt.%). ThirtyWistarrats were randomly assigned to three experimental groups: W-20 (20 W/80ß-TCP wt.%), W-60 (60 W/40ß-TCP wt.%), and W-80 (80 W/20ß-TCP wt.%), evaluated by optical microscopy at biological tests after 15 and 45 days of implantation. Throughout the study, the histological results evidenced that the scaffolds remained at the implantation site, were biocompatible and presented osteogenic potential. The percentage of neoformed mineralized tissue was more evident in the W-20 group (51%), at 45 days. The composite of the W-80 group showed more evident biodegradation than the biomaterials of the W-20 and W-60 groups. Thus, it is concluded that the scaffold containing 20 W/80ß-TCP (wt.%) promoted more evident bone formation, but all composites evaluated in this study showed notorious bioactivity and promising characteristics for clinical application.
Assuntos
Regeneração Óssea , Crânio , Alicerces Teciduais , Animais , Materiais Biocompatíveis , Compostos de Cálcio , Fosfatos de Cálcio , Ratos , Silicatos , Crânio/diagnóstico por imagemRESUMO
The objective of this study was to assess the resorption index of particulate calvarial grafts in maxillary sinuses of patients undergoing total reconstruction of an atrophic maxilla with residual alveolar bone that was less than, or equal to, 3mm thick. Twenty-one maxillary sinus floor elevations were carried out using particulate calvarial grafts in 11 individuals with totally edentulous maxillas. All patients had computed tomography (CT) before (T0), and 48hours (T1) and six months after surgery (T2). For each CT scan, linear measurements were taken of sections of the anterior, medial, and posterior regions of the maxillary sinus. There was a significant increase in the height of the maxillary sinus floor when T0 was compared with T1 (p=0.001). There was a statistically significant reduction in all maxillary sinus measurements when T1 was compared with T2; the mean height reduction being 2.36mm (16.87%) in the anterior region, 3.53mm (22.47%) in the medial region, and 2.21mm (22.78%) in the posterior region (p=0.001). Mean resorption was 20.7%. Autogenous calvarial bone used alone is an option for graft material in pneumatised maxillary sinuses and in cases where there is limited alveolar bone.
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Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Transplante Ósseo , Implantação Dentária Endóssea , Humanos , Maxila/diagnóstico por imagem , Maxila/cirurgia , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/cirurgia , Estudos ProspectivosRESUMO
The aim of this study was to characterize and evaluate zirconia/hydroxyapatite in a critical size calvarial defect model in rats. Zirconia/hydroxyapatite (80/20) scaffold was characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Critical size (8 mm) calvarial defects were created in wistar rats (n=48) and divided into four groups (90 days): G0 Group: positive control; G1 Group: hydroxyapatite; G2 Group: Zirconia; G3 Group: Zirconia/hydroxyapatite (80/20). Calvaria were subjected to Micro CT, histological and immunohistochemical analyses (RANK, RANKL, OPG, osteocalcin and FGF-2). IL-1 beta, IL-10 and TNF-alpha levels were analyzed by Elisa Immunoassay. The XRD analysis confirmed the formation of a crystalline structure and SEM showed the presence of regions corresponding to Zirconia and Hydroxyapatite. The Micro CT showed increased bone volume (BV/TV) and bone mineral density (BMD) in the G3 group (P<0.05). In addition, discrete periosteal bone formation was found at the interface of the defect edge and the external surface of the scaffold in the G3 group, showing osteocytes inside and osteoblasts (P<0.05) with scarce mononuclear inflammatory cells (P<0.01) in the central region of the defect. The immunostaining was moderate for RANKL, Osteocalcin and FGF-2 in the G3 group (P<0.5), while it was intense for OPG (P<0.001). IL-1 beta levels were decreased and IL-10 levels increased (P<0.05). Zirconia/hydroxyapatite (80/20) scaffold repair in critical size calvarial defects increased bone density, osteoblast and osteoclast cell numbers, FGF-2, osteocalcin and OPG immunostaining and IL-10 levels.
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PURPOSE: This study evaluated the autogenous graft resorption rate in a calvarial block graft in the anterior region of an atrophic maxilla and compared it with the thickness of the remaining ridge. MATERIALS AND METHODS: Twelve patients were included in the study. They were submitted to cranial calotte graft surgery, and there were 40 blocks in total. The thicknesses of the ridges in the crest, middle and apical regions of the blocks were evaluated by computed tomography scan at the times: preoperative (T0), 48 hours (T1) and 6 months (T2) after the reconstructions. RESULTS: The resorption of the blocks from T1 to T2 was 13.4%. The greatest remodeling occurred in the alveolar bone crest (20.07%), followed by the middle portion (12.28%), and the apical region (9.5%), but the three regions did not significantly differ between times T1 and T2 (crest P = .07, middle P = .124, apical P = .131). Recipient site with the lowest thickness had the greatest resorption rates (up to 2 mm = 17.6%; from 2 to 4 mm = 17.52%) while than those with a thickness greater than 4 mm had a mean resorption of 8.81%. CONCLUSIONS: The resorption of the grafts in this study was 13.4%. Higher resorption rates were observed in the alveolar crest areas, where the ridges were less thick.
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Aumento do Rebordo Alveolar , Transplante Ósseo , Maxila , Humanos , Estudos Prospectivos , Estudos RetrospectivosRESUMO
OBJECTIVE: This study proposes to evaluate, by means of microtomographic analysis, the topical potential of raloxifene combined with BioGran® through the sonochemical method in the repair of critical bone defects in the calvaria of rats. The hypothesis was that the homogenization of Raloxifene to Biogran at the 20% concentration would improve the bone repair at the grafted site. MATERIALS AND METHODS: A 5-mm calvaria bone defect was induced in three groups: CTR (100% BioGran®); RAL10 (90% BioGran® and 10% raloxifene), and RAL20 (80% BioGran® and 20% raloxifene). The animals were euthanized after 30 days and the microCT analysis was then performed to evaluate the parameters bone volume (BV), bone volume percentage (BV/TV), trabecular bone thickness (Tb.Th), and the separation and number of trabeculae (Tb.Sp and Tb.N). The obtained results were compared using ANOVA and Tukey test (p < 0.05). RESULTS: The best results were found for the CTR and RAL20 groups, in which the BV, BV/TV, Tb.Sp, and Tb.N parameters were statistically significant in comparison with RAL10 (p < 0.05). CONCLUSIONS: In view of the results obtained in this experiment, we can conclude that BioGran® alone or in an 80/20 mass concentration with raloxifene can lead to favorable bone formation.
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Densidade Óssea/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Cerâmica , Nanocompostos , Cloridrato de Raloxifeno , Crânio , Animais , Cerâmica/química , Cerâmica/farmacologia , Masculino , Nanocompostos/química , Nanocompostos/uso terapêutico , Cloridrato de Raloxifeno/química , Cloridrato de Raloxifeno/farmacologia , Ratos , Ratos Wistar , Crânio/lesões , Crânio/metabolismo , Crânio/patologiaRESUMO
Investigation on functional genome research may contribute to the knowledge of functional roles of different mRNAs and miRNAs in bone cells of osteoporotic animals. Currently, few studies indicate the changes in gene modulation that osteoporosis causes in osteoblastic cells from different sites. Thus, the purpose of this investigation was to evaluate cell viability, alkaline phosphatase activity and modulation of mRNAs/miRNAs in osteoblastic cells from calvaria and bone marrow by means of microarray technology. Wistar female rats were divided in sham operated and ovariectomized groups. After 150 days of ovariectomy, cells were isolated from both sites to perform cell culture. Results showed that calvaria cells from ovariectomized rats had a decrease in viability when compared to control groups and to bone marrow cells from osteoporotic rats after 3 days. Alkaline phosphatase activity decreased in calvaria cells from ovariectomized rats whereas it was increased in bone marrow osteoblastic cells in the same group. Microarray data analysis showed 5447 differentially expressed mRNAs and 82 differentially expressed miRNAs in calvaria cells. The same way, 4399 mRNAs and 54 miRNAs were expressed in bone marrow cells. mRNAs associated with bone metabolism such as Anxa5, Sp7, Spp1, Notch1 were distinctively modulated in both sites, as well as miRNAs such as miR-350, miR-542-3p, miR-204-5p, and miR-30e-3p. The RNA species identified in this study could be further used as targets for treatment or prevention of osteoporosis.
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Células da Medula Óssea/metabolismo , Menopausa/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Medula Óssea/metabolismo , Diferenciação Celular/genética , Feminino , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Osteoporose/metabolismo , Ovariectomia/métodos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Crânio/metabolismo , Transcriptoma/genéticaRESUMO
Aplasia cutis congenita (ACC) is a rare congenital malformation of primarily the skin; it is most commonly seen on the scalp but can occur anywhere on the body. The exact etiology is still unclear but there are many suggested causes. Classification systems have been proposed to help categorize patients and assist with treatment. Treatment options are controversial and range from conservative to surgical interventions. We report an extreme case of ACC that included a significant part of the skull. We discuss this case and review salient literature. Although such cases of ACC with bony involvement are rare, this aspect of the pathology should be kept in mind when treating or imaging such patients.
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Displasia Ectodérmica/patologia , Displasia Ectodérmica/cirurgia , Procedimentos Neurocirúrgicos , Crânio/cirurgia , Pré-Escolar , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/cirurgia , Feminino , Humanos , Imageamento por Ressonância MagnéticaRESUMO
OBJECTIVE: To evaluate the effect of a single-dose local administration of PTH on bone healing in rat calvarial bone defects by means of micro-computed tomography, histological and histomorphometric analysis. DESIGN: Critical-size cranial osteotomy defects were created in 42 male rats. The animals were randomly divided into 3 groups. In the C Group, the bone defect was only filled with a blood clot. In the S Group, it was filled with a collagen sponge and covered with bovine cortical membrane. In the PTH Group, the defect was filled with a collagen sponge soaked with PTH and covered with bovine cortical membrane. The groups were further split in two for euthanasia 15 and 60days post-surgery. Data was statistically analyzed with t-tests for independent samples or the nonparametric Mann-Whitney test when applicable. Intragroup comparisons were analyzed with paired t-tests (p<0.05). RESULTS: Micro-CT analysis results did not demonstrate statistically significant intergroup differences. At 15days post-surgery, the histomorphometric analysis showed that the PTH Group exhibited a significantly higher percentage of bone formation compared with the S Group. At 60days post-surgery, a higher percentage of new bone was observed in the PTH group. CONCLUSION: The results suggest that the local administration of PTH encouraged the bone healing in critical-size calvarial defects in rats.
Assuntos
Hormônio Paratireóideo/farmacologia , Crânio/efeitos dos fármacos , Crânio/patologia , Cicatrização/efeitos dos fármacos , Microtomografia por Raio-X/métodos , Animais , Regeneração Óssea/efeitos dos fármacos , Bovinos , Colágeno/farmacologia , Masculino , Osteogênese/efeitos dos fármacos , Hormônio Paratireóideo/administração & dosagem , Ratos , Ratos Wistar , Crânio/diagnóstico por imagem , Crânio/cirurgia , Fatores de TempoRESUMO
Abstract The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.
Resumo O objetivo deste estudo foi caracterizar físico-químicamente e avaliar o reparo ósseo de discos de hidroxiapatita porosa contendo zinco após a implantação em calvária de coelhos (nZnHA). O pó de nZnHA e o pó hidroxiapatita porosa estequiométrica nanoestruturada (controle - nHA) foram confeccionados em discos (8 mm) e calcinados a 550˚C. Dois defeitos cirúrgicos foram criados na calvária de seis coelhos para a implantação dos discos. Após 12 semanas, os animais foram eutanasiados e as áreas enxertadas foram removidas, fixadas em formol a 10% e embebidas em parafina (n=10) para avaliação histomorfométrica. Além disso, uma amostra de cada grupo (n=2) foi embebida em metilmetacrilato para análise de MEV e EDS. O tratamento térmico dos discos de nZnHA transformou-os em implantes bifásicos compostos por HA contendo Zinco e β fosfato tricálcico com Zinco (ZnHA/βZnTCP). Os discos de nHA, apresentaram-se altamente cristalinos e com baixa solubilidade quando comparados aos discos de ZnHA. A análise histológica revelou que ambos os materiais foram biologicamente compatíveis e promoveram a osteocondução. As análises de FRX e MEV-EDS confirmaram a presença do zinco nas amostras de nZnHA. A avaliação histomorfométrica revelou a presença de neoformação óssea em ambos os grupos, porém sem diferenças estatísticas entre eles, com base no teste de Wilcoxon (p>0,05). O presente estudo confirmou que ambos os biomateriais otimizaram o reparo ósseo, foram biocompatíveis e osseocondutivos e a presença do zinco não favoreceu o reparo ósseo. Estudos adicionais in vivo devem ser conduzidos a fim de investigar o efeito de maiores concentrações de zinco.
Assuntos
Animais , Coelhos , Durapatita/análise , Crânio/química , Zinco/análise , Materiais Biocompatíveis , Fluorescência , Microscopia Eletrônica de Varredura , Crânio/anatomia & histologia , Espectrofotometria Infravermelho , Difração de Raios XRESUMO
BACKGROUND: Supplementation of bone substitutes with recombinant platelet-derived growth factor-BB (PDGF-BB) can enhance bone regeneration. The aim of the study was to evaluate the effect of PDGF-BB on bone formation in the presence of ß-tricalcium phosphate and bovine bone mineral matrix in a rat calvaria defect model. METHODS: The authors examined 5 mm rat calvarial defects treated with ß-tricalcium phosphate (TCP) or demineralized bovine bone mineral (DBBM) with and without 0.3 mg/ml recombinant PDGF-BB. Calvaria defects were randomly divided into the following treatment groups (n = 5); TCP; TCP plus PDGF-BB; DBBM; DBBM plus PDGF-BB; and untreated empty control. After 45 days, bone formation was evaluated by histomorphometry and fluorescence microscopy. RESULTS: The authors report that the area of newly formed bone was similar between the empty controls and the two bone substitutes, TCP and DBBM. Supplementation of TCP and DBBM with PDGF-BB had no significant impact on bone formation. Fluorochrome staining revealed no visible changes in the pattern of bone formation in defects filled with TCP and DBBM, irrespective of PDGF-BB. Furthermore, supplementation with PDGF-BB did not influence biomaterial degradation. CONCLUSIONS: The authors concluded that PDGF-BB had no impact on bone formation and degradation of bone substitutes in the respective rodent models. Thus, possible beneficial effects of PDGF-BB may require other model situations.
Assuntos
Fosfatos de Cálcio/farmacologia , Osteogênese , Animais , Substitutos Ósseos , Bovinos , Minerais , Projetos Piloto , RatosRESUMO
Autogenous bone grafting is the gold-standard technique for bone augmentation procedures prior to implant placement. If the amount of available intraoral donor bone is insufficient, it is necessary to harvest bone graft from extraoral sites, such as calvaria. Although this technique is well established, only a few case reports show the histological analysis of the grafted bone at the moment of implant placement. This article reports the case of a 48-year-old female patient with a critical atrophic maxillary ridge reconstructed using autogenous calvarial bone graft prior to implant placement, with clinical and histological evaluation. Bone was collected under general anesthesia from the parietal bone. The outer cortical originated the bone blocks, and the medullar bone layer between was collected to be used in the sinus augmentation procedure, together with 5 of the bone blocks triturated. Six months after bone augmentation, 8 implants were placed in the grafted area and 2 biopsies were retrieved (anterior and the posterior regions), allowing the visualization of the bone-remodeling process in the grafted areas. The patient had a stable recovery. Our results showed that although necrotic bone could still be seen in the outer layer of the grafted area, the interface between this necrotic bone and the already remodeled bone was consistent with biocompatibility. Two-year radiographic evaluation showed success of the grafts and the implants in supporting an esthetic and functionally stable prosthesis. Summarizing, calvarial bone grafts are a viable alternative for the attainment of adequate bone volume prior to implant placement.
Assuntos
Aumento do Rebordo Alveolar/métodos , Autoenxertos/transplante , Transplante Ósseo/métodos , Implantes Dentários , Maxila/cirurgia , Osso Parietal/cirurgia , Levantamento do Assoalho do Seio Maxilar/métodos , Sítio Doador de Transplante/cirurgia , Atrofia , Biópsia , Remodelação Óssea/fisiologia , Prótese Dentária Fixada por Implante , Estética Dentária , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Arcada Edêntula/patologia , Arcada Edêntula/cirurgia , Maxila/patologia , Pessoa de Meia-Idade , Necrose , Resultado do TratamentoRESUMO
Introduction: The adipose tissue is an important reservoir of adult stem cells which have capacity of differentiating in osteoblasts with potential implication in reaching bone regeneration. The evaluation of the osteoblastic differentiation can be verified through immunohistochemical markers such as bone morphogenetic protein- 2 (BMP-2). Objective: To evaluate the immunoexpression of BMP-2 protein on the bone repairing of critical size defects (CSD) surgically created in rat calvaria and treated by autogenous macerated adipose tissue. Material and methods: Forty male rats had a CSD measuring 5 mm created on their calvaria. The animals were randomly divided into two groups: group C (control) and group AT (macerated adipose tissue grafting). In group C, the defect was filled with only blood clot. In group AT, the defect was filled with autogenous macerated adipose tissue. The groups were subdivided into two subgroups (n = 10) for euthanasia at 7 and 90 post-operative days. Histological and immunohistochemical analyses were carried out. Data were submitted to descriptive statistics (mode). Results: In group AT, both at 7 and 90 post-operative days, the main healing type was the presence of dense conjunctive tissue exhibiting bundles of collagen fibers disposed in beams permeating the remaining adipose tissue with rare heterotopic bone formation associated to fibrosis and different types of tissue necrosis. In group C, the repair was achieved by the formation of bundles of collagen fibers oriented parallelly to the surface of the wound at the two post-surgical periods. The immune-staining of BMP-2 was present only in group C (7 and 90 post-operative days). Conclusion: Within the limits of this present study, it can be concluded that the adipose tissue grafting did not favor bone neoformation in critical size defects and BMP-2 signaling was not observed.
RESUMO
Objetivo: avaliar a ação local do paratormônio sintético (PTH) na regeneração óssea em calvária de coelhas. Método: foram utilizadas 20 coelhas, adultas, que receberam um cilindro de titânio fixado na calvária. Os animais foram divididos em dois grupos: GC (controle) e GE (experimental). Em cada animal foi realizado, com auxílio de micromotor, descorticalização do osso no local onde foi implantado um cilindro de titânio com volume interno útil de 112 mm3. Cada cilindro, após fixação na calvária, foi preenchido por coágulo sanguíneo obtido do próprio animal. Ao coágulo do grupo experimental foi adicionado 20 µg de PTH sintético derivado de DNA recombinante humano. Após oito e 12 semanas, cinco animais de cada grupo foram anestesiadas, sendo o volume do cilindro avaliado e o tecido presente no interior do cilindro retirado e fixado em formol a 10%. Após fixação o material foi descalcificado e processado para inclusão em parafina. Foram feitos cortes de 5 µm que foram corados pela hematoxilina-eosina e tricrômico de Mallory. Foi feita avaliação histomorfométrica do tecido e os dados submetidos á análise estatística (P < 0,05). Resultados: notamos no interior dos cilindros a presença de tecido conjuntivo frouxo, trabéculas ósseas e regiões de medula óssea, sendo mais desenvolvido no grupo experimental, tanto na 8ª quanto na 12ª semana. A morfometria mostrou maior quantidade de tecido ósseo neoformado no interior dos cilindros, nos grupos experimentais, em relação aos controles. Conclusões: o uso do PTH estimula a formação de tecido ósseo no interior de cilindros implantados em calvária de coelhas.
Objective: to evaluate the local action of synthetic parathyroid hormone (PTH) in bone regeneration of calvaria rabbit model. Methods: twenty animals were divided into two groups: GC (control) and GE (experimental). In each animal, bone removal (decorticalization) was performed with a micromotor and a titanium cylinder (internal useful volume of 112 mm3) was implanted. Afterwards, all cylinders were filled by autogenous blood clots; in the experimental groups, 20ìg of synthetic PTH derived from recombinant human DNA was incorporated into the cylinders. After 8 and 12 weeks, five animals from each group were anesthetized, the cylinder volume measured and the tissue inside the cylinder removed and fixed in 10% formalin. After fixation, the material was decalcified, processed, and 5ìm-thick slices stained with hematoxylin-eosin and Mallory's trichrome. Histomorphometric analysis was made and data submitted to statistical analysis (p<.05). Results: The presence of loose connective tissue, bone trabeculae and bone marrow regions were observed in the cylinders, being more developed in the experimental group, both at 8th and 12th weeks. Also, a higher amount of newly formed bone tissue within the cylinders in the experimental groups compared to controls was seen. Conclusions: the use of PTH stimulated the formation of bone tissue within the cylinders implanted in the calvaria rabbit model.