Traumas nas asas de aves são muito comuns, causando lesões em tecidos moles e ossos, e tendem, muitas vezes a causar desvascularização da região, o que implica em complicação no tratamento além de facilitar a instalação de processo infeccioso. Com o objetivo de estudar possível vascularização via enxerto muscular pediculado, foram utilizados 12 pombos, divididos em dois grupos iguais (E e S), para a avaliação do uso de enxerto pediculado de músculo peitoral como técnica de revascularização de defeito criado em porção distal de bíceps braquial. As asas contralaterais de todos os animais foram utilizadas para a avaliação termográfica, sendo este grupo de n=12 denominado C. As asas contralaterais de dois animais foram utilizadas como controle anatômico para a avaliação histomorfométrica, grupo este denominado A. Realizaram-se avaliações clínica, termográfica, angiográfica e histomorfométrica para quantificação e qualificação da vascularização, e determinação da viabilidade desta técnica, em até vinte e um dias. A técnica causou pouca morbidade, exceto em dois animais do grupo E que apresentaram necrose parcial do enxerto, porém isto não resultou em falha da técnica. As avaliações termográficas demonstraram que imediatamente após a cirurgia, tanto leito doador, quanto leito receptor apresentaram redução da temperatura, porém esta temperatura aumentou gradativamente, sendo que no grupo E, a temperatura, aos sete dias foi mais baixa, quando compaprada ao grupo S e ao grupo A, e aos catorze dias não houve diferença significativa entre os grupos. A avaliação angiográfica post mortem determinou patência de vasos principais e secundários em todos os animais, comprovando tratar-se de técnica que causa baixa mortificação do tecido no sítio doador, e na asa. A avaliação histomorfométrica incluiu dados de área total de vasos por amostra, área total de tecido, diâmetro médio dos vasos, número absoluto de vasos, e percentagem de tecido ocupada por vasos. Tal avaliação demonstrou aumento importante da vascularização dos dois grupos avaliados, sendo que o único parâmetro que apresentou diferença entre os dois, foi o número de vasos, aumentado no grupo E. Conclui-se que o enxero apresenta neovascularização importante, e provavelmente cria ambiente adequado para promover cicatrização de lesão pobremente vacularizadas em aves. / Trauma in avian wings is very common, causing lesions in soft tissue and bones, and they tend to, many times, cause avascularization of the region, which aggravates treatment and allows for the installation of infectious processes. Twelve pigeons, divided in two equal groups (E and S) were used for the evaluation of the use of a pectoral muscle flap as revascularization technique for a distal biceps brachii defect. Contralateral wings os all animals were used for termographic evaluation, and this group with n=12 was called C. Contraletarl wings of two animals were used as anatomic control for the histomorphometric evaluation, and this group was called A. Clinical, termographic, angiographic and histomorphometric evaluations were made to quantify and qualify the vascularization, and determine the viability of this technique. The technique caused little morbidity, except for two animals in group E, who had partial necrosis of the grafts, but that didnt result in failure of the technique. Termography showed that after surgery, both, donor and receptor sites had a reduced temperature, but it increased gradually. Group E showed a lower temperature at seven days, when compared to group S and to group C, and at fourteen days, there was no significant difference between groups. Post mortem angiografic evaluation determined patency of main and secondary vessels in all animals, proving to be a low morbidity technique for the donor site and for the wing. Histomorphometric evaluation includes total area of vessels and of soft tissue, mean vessel diameter, total vessel number and percentage of soft tissue covered by vessels. This evaluation showed and important increase of vascularization of both groups, and only total number of vessels was different among groups, being bigger in group E. We conclude that the graft shows important neovascularization, and probably creates adequate environment for the healing of little vascular bird wounds.

Abstract This study focuses on the development of a bone collecting device for intra-oral bone harvesting and on the introduction of a new bone graft donor site, zygomatic bone. A bone collector was constructed and tested in vitro. This bone collector is suitable and efficient in dental implant related bone grafting surgery. It was also found to be more efficient and with a larger capacity in bone harvesting when compared to the two commercially available bone collectors. A zygomatic bone harvesting technique is introduced in this study. The safety and morbidity of the method was assessed in a cadaver and a prospective clinical study. In the cadaver study, 40 procedures were performed. The complications during the cadaver harvesting included 15 perforations into the maxillary sinus and 7 perforations into the infratemporal fossa. The only intra-operative complication in 32 clinical operations was perforation of the maxillary sinus in 33% of the zygomatic sites. None of these patients experienced any post-operative problems related to the perforation. Patients needed pain medication for a mean time of four days and they did not demonstrate any paresthesias or altered sensations in the donor area. The yield of the bone graft from zygomatic bone was quantified in cadaver and clinical studies. In the cadaver study, the average yield of the graft was 0.59 ml. In the clinical study the average graft volume was 0.90 ml. The required reconstructions were accomplished in all clinical cases. In the prospective clinical study, the bone grafts from the zygomatic bone were used simultaneously with one-stage dental implants placement. Bone grafting was employed at 72 of the 82 implant sites. Two of the bone grafted implants failed, yielding a survival rate of 97.2% for bone grafted implants and 97.6% for the whole study group. Grafted sites healed remarkably well, and no obvious signs of graft resorption were noted during the 26.9 months follow-up period. The bone collector developed in this study is an effective instrument in intra-oral bone harvesting. The zygomatic bone can be regarded as a safe bone harvesting donor site and the yield of bone graft from this area is sufficient for moderate defects in resorbed alveolar ridges.

Since the late 20th century, breakthroughs in technology have been occurring expeditiously. Indeed, technological innovations have provided the betterment of many aspects of life and ensured humans’ appropriate forms of evolution and civilization. It is safe to claim that medicine has advanced within the past few decades, especially with the upbringing of technological innovations. The world of medicine would not have experienced its recent breakthroughs and profound discoveries without utilizing the available technology. The improvements observed in medicine and technology resulted in better providing of healthcare. Customizing treatments for each patient is now possible. One method of applying customization is through 3D printing of materials such as artificial prosthetics, tissues, and organs. This literature review analyzes 3D printing by stating definitions, assessing its history, discussing its different applications and closing with evaluating future directions. 3D printing first appeared in the late 20th century, and its primary purpose was to design and manufacture products efficiently and accurately. Traditional production of structures involves subtractive manufacturing (carving, cutting, and other methods of reshaping materials) to achieve desired products, whereas 3D printers implement additive manufacturing (a layer-by-layer approach). This provides less time, greater accuracy, and labor-free fabrication of products. Computerized software is one of the essential parts of 3D printing, and functions include designing, scaling, visualizing, controlling production frequency, and many more. In medical applications, the software may require CT scans, cone beam computed tomography, and intraoral scanners (for dental applications). The 3D printing techniques identified in this review are generally applied in oral and maxillofacial procedures—stereolithography, which constructs a product layer-by-layer through curing liquid resin using a UV laser. Digital light projection is a method similar to stereolithography, with a few differences, such as using a UV light instead of a laser and using a liquid crystal display panel. Fused deposition modeling is a technique that melts plastic filaments and extrudes them through a nozzle to form a structure in a layer-by-layer fashion. Selective laser sintering is also similar to stereolithography, where it uses a laser to form an object layer by layer, but the material is a thin layer of plastic powder instead of liquid resin. The power binder printing technique applies droplets onto powdered materials, adhering and forming layers as designed via computerized software. Lastly, computed axial lithography is similar to digital light projection, except the light is projected from many angles at once instead of one layer at a time. The main objectives of this literature review are to investigate each technique, discuss the advantages and disadvantages, and list the commonly applied areas in medicine for each. Also, this review evaluates the current limitations experienced when using 3D printers and suggestions for overcoming them. Some limitations include, but are not limited to, excessive time allocated for producing specific structures, accurate capturing of surgical sites, use of appropriate materials that form printed structures, cost, and deficiencies of reported data. Lastly, this literature review assesses the future projections. The future holds promising breakthroughs in 3D printing technology, including the fabrication of dental stem cells, operating artificial organs, complex vascular tissues, customized artificial alveolar structures for oral and intracranial procedures, and regeneration of periodontal tissues. These projections may occur by overcoming the most reported limitations. Medicine is digitizing rapidly and will continue adapting to the latest technological inventions. The current efforts to advance 3D printing technology will likely positively impact the advancement of many fields, including healthcare, increase chances of positive postoperative outcomes, and potentially combat many health issues society faces today. Professionals across disciplines must come together to further research and educate curriculums to revolve around the innovative technologies to continuing education courses related to 3-D printing technologies.

[pt] Em todas as atividades cirúrgicas, que se ocupam dos tecidos estruturais do ser humano, existem situações em que se faz necessário o emprego de tecido ósseo adicional. As indicações mais comuns para esse emprego de preenchimento ósseo são pequenas e médias reconstruções. O estudo de tecido ósseo é uma parte da engenharia de biomateriais que tem a finalidade básica de formar substitutos ósseos. O presente trabalho teve como objetivo principal caracterizar dois materiais, sendo um de origem bovina (Pro-Bone) e o outro de origem sintética (TCP-trifosfato de cálcio), como materiais de preenchimento em defeitos ósseos. A difração de raios x e a espectroscopia de infra vermelho revelaram que o osso bovino é altamente cristalino e composto por hidroxiapatita - HA, carbonatos e compostos minoritários. Em relação ao TCP os resultados demonstraram razão atômica Ca/P igual a 1,5 e alta cristalinidade. As partículas de ambos os materiais, foram analisadas a partir de imagens digitais (MO e MEV), utilizando o programa KS-400. Desta forma, foram medidas as dimensões relacionadas ao tamanho e à forma das partículas: área, perímetro, eixo maior, eixo menor, diâmetro médio, circularidade e convexidade. Observou-se que a área das partículas de Pro-Bone é, em média, cerca de 10 vezes menor do que a área das partículas de TCP. O menor tamanho das partículas de Pro-Bone pode levar a uma reabsorção muito mais rápida do material do implante, gerando fibrose e limitando a osteo-integração. Do ponto de vista da forma, não foram encontradas diferenças significativas entre os dois materiais. / [en] In all the surgical activities that are occupied with structural tissue of the human being, we have situations presented where it is necessary the use of additional bone tissue. The most common indications to use bone fulfilling are: small reconstructions and average reconstructions. The patient, who needs bone reconstruction surgery of small and medium average, can make use of allopathic material, with a cost well more accessible than bone graft alogenic. The study of a bone tissue is a part of engineering with basic purpose to form bone substitutes. This work had as priority the objective to characterize two materials, one with bovine origin e another one with synthetic origin, for future applications as material of fulfilling in bone defects. The X-Ray diffraction and the infra red spectroscopy had disclosed that bovine bone is highly crystalline and composed for hidroxiapatite - HA, carbonates and composites minority and the same with TCP. The bone particles were measured from digital images (MO and the MEV), using program KS- 400. The dimensions related to the particle size and form had been measured based on: area, perimeter, bigger axle, lesser axle, average diameter, factor of form, convexity and diameter of Ferret. It was observed that the particles area of Pro-Bone is, in average, about 10 times smaller than TCP particles area. The smaller particle size of Pro-Bone can lead to a much faster reabsortion of the implant material, generating fibroses and limiting the osteo-integration. No significant differences in shape between the two materials were found.

Bovine bone grafts (BBX) require protein removal as part of the manufacturing process to reduce antigenicity and, in consequence, to be safely used in humans. Deproteinisation may have direct effects on the characteristics of the bone material and on in vivo material performance. This research aimed to comprehensively study the physicochemical and mechanical properties of BBX processed at low deproteinisation processing temperatures. Cubes of bovine bone (8 mm3) were treated with temperatures between 100 °C and 220 °C at 30 °C intervals and with pressures ranging from 1.01 to 24.58 Bar. The samples were characterised topographically and mechanically using scanning electron microscopy (SEM), atomic force microscopy (AFM), and uniaxial bending tests. The organic content and the chemical composition were determined using thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) and FTIR were also used to quantitatively determine the specimen crystallinity. Increasing temperature/pressure was associated with decreasing protein levels and compressive strength and increasing surface irregularities and crystallinity. The findings suggest that low-temperature processed bone is likely to exhibit a rapid in vivo degradation rate. The deproteinisation temperature can be adjusted to tailor the graft properties for specific applications.

Calcium phosphate (CP) materials have been used extensively for bone replacement and augmentation due to their similarity to the mineral component of bone. In addition to being non-toxic, they are biocompatible, not recognized as foreign materials in vivo, and most importantly, exhibit osteoconductive behavior, being able to help in bone formation during healing. CPs form an intimate physicochemical bond with the host tissue, termed osseointegration. However the main limitation of calcium phosphates is their inherent brittle nature and poor mechanical performance under complex stress states. As a result, these materials have been used clinically only in non-load-bearing applications, primarily as granules. The primary goal of this research was to enhance mechanical performance of CPs, tricalcium phosphate (TCP) and hydroxyapatite (HAp) to be precise, in an attempt to develop controlled strength-loss resorbable/ bioactive ceramic bone-grafts for hard tissue engineering. In my work on TCP, I selected and introduced small quantities of single and multi-oxide sintering additives in TCP, to study their influence on sintering behavior, densification, mechanical properties and biodegradation/ biomechanical properties in vitro. Through this research, I could improve mechanical performance of [Beta]-tricalcium phosphate ([beta]-TCP) and controlled its rate of biodegradation by introducing of certain additives. In my second work, I improved mechanical performance of HAp (Ca10(PO4)6(OH)2 by reducing particle-size of the powder through the synthesis of stoichiometric, nanocrystalline, single phase HAp powder in the range of 2-20 nm. Synthesis of powder was accomplished via a modified low temperature sol-gel technique using ethanol/ water as solvent.

No description available.

A inflamação é um evento intrínseco ao transplante que é desencadeado após o dano causado pela cirurgia. No presente trabalho realizou-se a caracterização fenotípica e funcional das células inflamatórias presentes no enxerto, após o transplante alogênico ou singênico de pele em camundongos. Os resultados obtidos mostraram diferenças significativas na produção de citocinas pró e anti-inflamatórias entre o transplante alogênico e singênico, diferenças já detectáveis nas primeiras 24 horas pós-transplante. Mostrou-se que existe produção aumentada de IL-10 no transplante singênico em relação ao transplante alogênico indicando que a produção de IL-10 no enxerto possui um importante papel para o aceite de transplantes de pele. Além disso, na ausência de IL-10, a rejeição de enxertos alogênicos apresentou-se acelerada e surpreendentemente uma grande parcela dos enxertos singênicos não foi aceita e apresentava aspecto de fibrose com grande deposição de colágeno. O conjunto dos dados indica que a IL-10 possui um importante papel regulatório na inflamação local do enxerto. / Inflammation is an intrinsic event of transplantation that occurs due to to damage caused by surgery. In this study, phenotypic and functional characterization of inflammatory cells present in the graft was performed, after allogeneic or syngeneic skin transplantation in mice. Our results show significant differences in the production of pro and anti-inflammatory cytokines between the syngeneic and allogeneic grafts, detectable as early as 24 hours after transplantation. Higher production of IL-10 was shown in the syngeneic grafts in comparison to allogeneic grafts, indicating that production of IL-10 in the graft is important for acceptance. This is reinforced by data that shows that in the absence of IL-10, rejection of allografts is accelerated and that, surprisingly, a high percentage of the syngeneic grafts is not accepted as well, or shows fibrosis with high deposition of collagen. Taken together, this data indicates that IL-10 has an important regulatory function in the local inflammation of the graft.

No description available.

Submitted by Verônica Esteves (vevenesteves@gmail.com) on 2017-09-28T19:33:45Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Flávio Gasperini.pdf: 2318649 bytes, checksum: af9486980e507779dbd5975709e84b4d (MD5) / Approved for entry into archive by Verônica Esteves (vevenesteves@gmail.com) on 2017-09-28T19:34:10Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Flávio Gasperini.pdf: 2318649 bytes, checksum: af9486980e507779dbd5975709e84b4d (MD5) / Made available in DSpace on 2017-09-28T19:34:10Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Flávio Gasperini.pdf: 2318649 bytes, checksum: af9486980e507779dbd5975709e84b4d (MD5) Previous issue date: 2010 / Consultório / Os defeitos críticos ósseos oriundos de trauma, tumores ou doenças degenerativas determinam um desafio no campo da Ortopedia, visto que a reconstrução cirúrgica se faz necessária através de enxertos ósseos. Apesar de os enxertos autógenos serem considerados um “padrão ouro”, as cerâmicas sintéticas a base de Hidroxiapatita (HA) são materiais muito promissores, devido às suas inerentes características biocompatíveis. A possibilidade de diminuição do tamanho das partículas em escala nanométrica e o advento da hidroxiapatita nanoestruturada podem melhorar a remodelação óssea. O objetivo deste estudo foi avaliar a resposta tecidual e a biocompatibilidade de esferas de HA produzidas a partir de partículas nanométricas em comparação às esferas de HA produzidas a partir de partículas micrométricas, ambas no estado sinterizado e não-sinterizado (Sem tratamento térmico), bem como seu potencial de degradação e osteogênese, em relação ao grupo controle (coágulo). Os biomateriais foram implantados em defeitos ósseos nas tíbias de 12 coelhos da raça Nova Zelândia (Oryctolagus cuniculus), pesando entre 2000g e 3500g. As esferas (425-600 μm) tiveram as propriedades físicas e químicas caracterizadas por DRX, FT-IR, MEV e foram também submetidas ao teste de dissolução. Os animais foram divididos randomicamente em cinco grupos: Grupo 1 (Controle) – coágulo sanguíneo; Grupo 2 – HA Sinterizada; Grupo 3 – HA Sem tratamento térmico; Grupo 4 – NanoHA Sinterizada; e Grupo 5 – Sem tratamento térmico. Os animais foram mortos 7 e 28 dias após a cirurgia e as amostras submetidas ao processamento histológico. As esferas não-tratadas eram menos cristalinas que as sinterizadas (DRX e FT-IR), sendo mais solúveis in vitro (teste de dissolução). In vivo, a nanoHA e a HA, ambas sem tratamento térmico, dissolveram e promoveram maior formação de tecido ósseo em relação às esferas sinterizadas. Concluiu-se que os materiais se mostraram biocompatíveis e osteocondutores, porém a neoformação óssea foi mais acentuada nos grupos da HA e nanoHA não-tratadas termicamente. / Bone critical defects from trauma, tumors or degenerative diseases prescribe a challenge in orthopedics, since surgical reconstruction is required by bone grafts. Although autografts are considered a gold standard, the synthetic ceramics based on hydroxyapatite (HA) are promising materials due to their inherent characteristics biocompatible. The possibility of decreasing the size of the particles at the nanometer scale and the advent of nanostructured hydroxyapatite may improve bone remodeling. The aim of this study was to evaluate the tissue response and biocompatibility of HA spheres shape made from nano-sized particles compared to the HA spheres made from micro-sized particles, both in sintered and non-heat treated as well as its potential for degradation and osteogenesis compared to control group (clot). The spheres (425-600 μm) had the physical and chemical properties characterized by XRD, FT-IR, SEM and were also subjected to dissolution test and the biomaterials were implanted in bone defects on 12 New Zealand rabbit’s tibiae (Oryctolagus cuniculus), weighing between 2000g and 3500g. The animals were randomly divided into five groups: Group 1 (Control) - blood clot, Group 2 - sintered HA, Group 3 - non-heat treated HA, Group 4 - sintered NanoHA and Group 5 - non-heat treated NanoHA. Animals were euthanized at 7 and 28 days after surgery and samples submitted to histological procedings. The non-heat treated had a lower cristallinity that the sintered materials (XRD and FT-IR), being more soluble in vitro (dissolution tests). In vivo, NanoHA and HA, both non-treated, degraded and promoted greater bone formation in relation to the sintered spheres. In conclusion, materials showed biocompatibility and osteoconduction, but the bone formation was more accentuated in the non-heat treated groups.