Master of Science / Department of Clinical Sciences / Daniel Thomson / The objectives of this study were to examine the effect of anabolic implants on nutrient balance, metabolic status, and growth factors in animals consuming nutrients either adequate or inadequate to support growth. Sixteen crossbred steers (BW 293 ± 19.3 kg) were trained to individual Calan gates, and randomly assigned to one of four treatments in a 2x2 factorial arrangement: (1) administration of an anabolic growth implant, and fed a moderate energy starting cattle diet at 2.0 × maintenance; (2) implant administration, and fed the same starting diet at 1.0 × maintenance; (3) no implant, and 2.0 × maintenance; (4) no implant and 1.0 × maintenance diet. Cattle were implanted with RevalorXS, containing 200 mg TBA and 40 mg estradiol. Animals were weighed on d 0, 14, and 28, with total gain, ADG, and feed efficiency determined at each time point. Blood samples were taken from each animal at d 0, 14, and 28 and used in determining serum concentrations of IGF-1 and plasma urea nitrogen (PUN). Serum collected on d 14, and 28 was applied to satellite cells (previously isolated from non-study steers and frozen). Protein abundance of myosin heavy chain (MYH; d 0, 14, and 28), phosphorylated extracellular signal related kinase (pERK; d 0 and 28), and phosphorylated mammalian target of rapamycin (pmTOR; d 0 and 28) was analyzed in differentiated satellite cells to determine effects of implant, intake, and their interaction (applied via the serum). There was a significant effect of diet on weight (P < 0.0001). There was a tendancy for an interaction between diet and implant on PUN (P = 0.09). Only diet had an effect on IGF-1 levels (P < 0.001). Implant increased MYH abundance (P < 0.01), and the abundance of pERK (P < 0.01). At high intake, implant increased abundance of pmTOR (P = 0.02) but had no effect on pmTOR at restricted intake (P = 0.21; interaction P < 0.01). These preliminary results show that implantation, which has previously been shown to improve gain, ADG, and feed efficiency, may not be as beneficial in cattle fed a restricted diet.

by Pang Sai Yau. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves [87-90]). / Chapter chapter one： --- introduction / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- biology of cancellous bone grafts --- p.2 / Chapter 1.2.1 --- Biology of bone graft incorporation --- p.2 / Chapter 1.2.1.1 --- Osteogenesis --- p.2 / Chapter 1.2.1.2 --- Vascularization --- p.3 / Chapter 1.2.1.3 --- Osteoinduction --- p.3 / Chapter 1.2.1.4 --- Osteoconduction --- p.4 / Chapter 1.2.2 --- Histological changes of bone grafts after bone transplantation --- p.4 / Chapter 1.2.2.1 --- Histologic pictures of cancellous autograft --- p.4 / Chapter 1.2.2.2 --- Histologic pictures of cancellous bone allograft --- p.5 / Chapter 1.2.2.3 --- Summary of the histologic changes of bone grafts --- p.5 / Chapter 1.3 --- application of cancellous bone grafts --- p.6 / Chapter 1.3.1 --- Principles of graft incorporation --- p.6 / Chapter 1.3.1.1 --- Operative site --- p.6 / Chapter 1.3.1.2 --- Graft material --- p.7 / Chapter 1.3.1.2.1 --- Autogenic cancellous bone --- p.8 / Chapter 1.3.1.2.2 --- Autogenic cortical bone --- p.9 / Chapter 1.3.2.2.3 --- Vascularized autogenic bone grafts --- p.9 / Chapter 1.3.2.2.4 --- Bone allografts --- p.10 / Chapter 1.3.2.2.5 --- Graft adjuncts and substitutes --- p.11 / Chapter 1.3.2.3 --- Systemic factors influencing gaft incorporation --- p.13 / Chapter 1.3.2.4 --- Local factors influencing graft incorporation --- p.13 / Chapter 1.3.3 --- Bone graft complications --- p.13 / Chapter 1.3.4 --- Placement of a graft --- p.14 / Chapter 1.3.5 --- Bone graft harvesting --- p.15 / Chapter 1.3.5.1 --- Iliac bone graft --- p.15 / Chapter 1.3.5.2 --- Femoral head bone allograft --- p.16 / Chapter 1.4 --- Application of flow conductance concept in a cancellous bone graft --- p.17 / Chapter 1.4.1 --- Physical structure of cancellous bone --- p.17 / Chapter 1.4.2 --- Porosity of cancellous bone --- p.17 / Chapter 1.4.3 --- Flow conductance concept --- p.18 / Chapter chapter two： --- material and method / Chapter 2.1 --- Transplantation of cancellous bone graft - Rabbit model --- p.19 / Chapter 2.1.1 --- Preparation of porcine cancellous bone graft --- p.19 / Chapter 2.1.1.1 --- Bone drilling --- p.19 / Chapter 2.1.1.2 --- Defat and freeze-dry --- p.20 / Chapter 2.1.2 --- Flow conductance measurement --- p.21 / Chapter 2.1.2.1 --- Porosity measurement --- p.21 / Chapter 2.1.2.2 --- Conductance measurement --- p.24 / Chapter 2.1.3 --- Rabbit model --- p.26 / Chapter 2.1.4 --- Methods of assessment --- p.29 / Chapter 2.1.4.1 --- Intraosseous pressure measurement --- p.29 / Chapter 2.1.4.2 --- Histologic study --- p.30 / Chapter 2.1.4.3 --- Blood flow study - use of tracer microspheres --- p.30 / Chapter 2.2 --- Flow conductance measurement of human cancellous bone --- p.34 / Chapter chapter three： --- results / Chapter 3.1 --- Results of the effects of various conductance of the grafts on bone healing in animal model --- p.38 / Chapter 3.1.1 --- Intraosseous pressure measurement --- p.38 / Chapter 3.1.2 --- Histological study --- p.40 / Chapter 3.1.3 --- Blood flow study of cancellous bone grafts --- p.52 / Chapter 3.2 --- Human specimens study --- p.62 / Chapter chapter four： --- discussion / Chapter 4.1 --- Discussion of the results in vivo study --- p.66 / Chapter 4.1.1 --- Intraosseous pressure measurement - a baseline study --- p.66 / Chapter 4.1.2 --- Effects of flow conductance of porcine cancellous grafts on bone regeneration --- p.67 / Chapter 4.1.2.1. --- Threshold conductance --- p.67 / Chapter 4.1.2.2. --- Histological score --- p.68 / Chapter 4.1.3 --- Discussion of graft healing from the blood flow study --- p.70 / Chapter 4.1.3.1 --- Tibia blood supply in relation to bone healing --- p.70 / Chapter 4.1.3.2 --- Effect of different flow conductance on blood flow changes in the tibia-graft structure --- p.72 / Chapter 4.1.4 --- "Comparison of length, porosity and conductance as the parameter on graft healing" --- p.74 / Chapter 4.2 --- Discussion on human bone specimens study --- p.76 / Chapter 4.3 --- General discussion --- p.78 / Chapter 4.3.1 --- The limitation of the animal model --- p.78 / Chapter 4.3.2 --- Some problems related to the clinical aspects --- p.79 / Chapter chapter five： --- conclusion --- p.81

Orientador: Idelmo Rangel Garcia Júnior / Coorientador Francisley Ávila Souza / Banca: Ana Paula Farnezi Bassi / Banca: Thallita Pereira Queiroz / Banca: Rodrigo dos Santos Pereira / Resumo: Modificações físicas e/ou químicas das superfícies dos implantes de titânio podem ser realizadas com intuito de facilitar e estimular o processo de osseointegração, consequentemente favorecendo um tempo de reparo mais curto. Sendo assim, o objetivo deste estudo foi avaliar as superfícies de implantes de titânio, modificadas com deposição de β-tricálcio fosfato pelo método biomimético, inseridos na maxila após levantamento de seio maxilar de coelhos, por meio da análise topográfica, biomecânica, microtomográfica, histológica e imunoistoquímica. Dezoitos (18) coelhos da raça Nova Zelândia (Albinus) receberam trinta e seis (36) implantes após elevação da membrana do seio maxilar bilateral. Foram divididos em dois grupos: No Grupo SBF - Implantes com superfícies modificadas pelo tratamento biomimético e preenchimento do seio maxilar esquerdo com coágulo; Grupo TCP - Implantes com superfícies modificadas com deposição de β-tricálcio fosfato pelo método biomimético e preenchimento do seio maxilar direito com coágulo. Os períodos de estudos foram de 7, 15 e 40 dias, onde foram realizadas as avaliações biomecânica, microtomográfica, histométrica e imunoistoquímica. Nas análises físico-químicas de microscopia eletrônica de varredura- MEV, espectroscopia de energia dispersiva- EDS e mapeamento da mineralização observou-se a formação de uma camada de apatita com maiores quantidades de Ca e P nos implantes com deposição biomimética com β-tricálcio fosfato. O teste de molhabilidade monstr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Physical and/or chemical modifications of the surfaces of the titanium implants can be performed in order to facilitate and stimulate the osseointegration process, consequently favouring a shorter repair time. Thus, the objective of this study was to evaluate the surfaces of titanium implants, modified with deposition of β-tricalcium phosphate by the biomimetic method, inserted in the maxilla after lifting the maxillary sinus of rabbits, employing topographic, biomechanical, histological and immunohistochemical analysis. Eighteen (18) New Zealand rabbits (Albinus) received thirty-six (36) implants after bilateral maxillary sinus membrane elevation. They were divided into two groups: In the SBF Group - Implants with surfaces modified by the biomimetic treatment and filling of the left maxillary sinus with clot; Group TCP - Implants with modified surfaces with deposition of β-tricalcium phosphate by the biomimetic method and filling of the right maxillary sinus with clot. The study periods were 7, 15 and 40 days, where the biomechanical, microtomographic, histometric and immunohistochemical evaluations were performed. In the physico-chemical analyzes of scanning electron microscopy (SEM), dispersive energy spectroscopy (EDS) and mapping of mineralization, the formation of an apatite layer with higher amounts of Ca and P was observed in implants with biomimetic deposition with β-tricalcium phosphate. The wettability test showed high hydrophilicity surfaces in this group of impla... (Complete abstract click electronic access below) / Doutor

Orientador: Valfrido Antonio Pereira Filho / Resumo: O presente trabalho teve como objetivo avaliar a qualidade óssea das diferentes regiões alveolares da maxila e da mandíbula por meio da classificação óssea proposta por Leckholm e Zarb (1985) (L & Z), radiografias panorâmicas e periapicais, quociente de estabilidade do implante (ISQ), torque de inserção (TI), microtomografia computadorizada (micro-CT) e histomorfometria. Como objetivo secundário, foi avaliada a correlação entre os diversos métodos citados acima. Foram avaliadas 60 áreas edêntulas, sendo 15 áreas de cada quadrante da maxila e da mandíbula. A qualidade óssea tipo III foi a mais frequente na maxila posterior (73,33%) e anterior (73,33%), já a tipo II foi mais frequente na mandíbula posterior (53,33%) e anterior (60,00%). Foi observada uma diferença estatisticamente significante na densidade óssea óptica avaliada por meio de radiografias periapicais na região posterior da maxila (2,38±1,06) e posterior da mandíbula (3,84±0,68), em relação às demais regiões alveolares avaliadas (p≤0,015). Nas radiografias panorâmicas não foram observadas diferenças entre a densidade óptica das regiões alveolares (p=0,6322). A estabilidade inicial dos implantes instalados na região posterior da maxila foi estatisticamente diferente dos instalados na região posterior da mandíbula, tanto na avaliação por meio do TI como por meio do ISQ (p<0,05). Também foi possível detectar diferenças na qualidade óssea das regiões alveolares da maxila e da mandíbula por meio de vários parâmetros da ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to evaluate the bone quality of the different alveolar regions of the maxilla and mandible through of the classification proposed by Leckholm e Zarb (1985) (L & Z), panoramic and periapical radiographs, implant stability quotient (ISQ), insertion torque (IT), microcomputed tomography (micro-CT) and histomorphometric analysis. The secondary objective was to evaluate the correlation between the several methods mentioned above. Sixty edentulous areas were evaluated, being 15 areas from each quadrant of the maxilla and mandible. The bone quality III was the most frequent in the posterior (73.33%) and anterior maxilla (73.33%) and quality II was the most frequent in the posterior (53.33%) and anterior (60.00%) mandible. A significant statistical difference was observed in the optical bone density evaluated through periapical radiographs of the posterior maxilla (2.38 ± 1.06) and posterior mandible (3.84 ± 0.68), in relation to the other alveolar regions (p≤0.015). With the panoramic radiograph no differences were observed between the optical density of the alveolar regions (p= 0.6322). The primary stability of the implants in the posterior maxilla was different from the posterior mandible, both in the evaluation through the TI and ISQ (p<0.05). It was possible to detect differences in the bone quality of the alveolar regions using several micro-CT parameters (BV, p≤0.002; BV/BT, p≤0.044; BS/TV, p <0.05; Tb.N, p<0.01 and Tb.Sp, p <0.05). With the histometry it was ... (Complete abstract click electronic access below) / Doutor

Orientador: Alessandro Roger Rodrigues / Banca: Hidekasu Matsumoto / Banca: Marcos Valerio Ribeiro / Resumo: Ligas metálicas destinadas a implantes, de um modo geral, têm sido cada vez mais pesquisadas quanto às suas propriedades mecânicas, microestruturais e características de biocompatibilidade. Apesar do surgimento de inúmeros materiais poliméricos, o titânio e suas ligas representam ainda a grande gama de aplicações na área da implantodontia. O titânio é considerado um material de difícil usinabilidade, pois desenvolve altas tensões e temperaturas em uma área de corte 2/3 menor que a de outros materiais. Assim, os parâmetros de usinagem e a ferramenta de corte necessitam ser adequadamente especificados, pois tanto a matéria-prima quanto o processo de fabricação levam a um alto valor agregado do produto final. Este trabalho determinou os efeitos da velocidade de corte e da profundidade de usinagem na usinabilidade (força de corte e energia específica de corte) e integridade superficial (microdureza e acabamento) no roscamento de implantes dentários de titânio comercialmente puro (grau 4, ASTM F67). Os ensaios foram realizados em torno CNC de cabeçote móvel, empregando ferramenta de metal duro revestida de TiAlN e fluido de corte abundante. Com base na Análise de Variância (ANOVA), os resultados mostraram que os parâmetros de corte afetam a usinabilidade e a integridade superficial da rosca, sendo a profundidade de usinagem o fator mais influente. Níveis muito baixos ou altos da profundidade de usinagem elevam a energia específica e a força de corte, respectivamente, encruando a subsuperfície da rosca e prejudicando a rugosidade dos flancos dos filetes. Velocidades de corte menores tendem a aumentar a força e a energia específica de corte, prejudicando o acabamento da rosca, mas não influem em sua dureza. Rugosidades estatísticas "Skewness" e "Kurtosis" apontaram a prevalência de picos agudos na superfície da rosca, favorecendo a osseointegração. Testes na condição High-Speed Cutting (HSC) indicaram ... / Abstract: Metallic alloys applied to implants have been researched aiming at improving their mechanical properties, microstructure and biocompatibility. Despite appearing several types of polymers in the last years, titanium and its alloys are still used extensively in the implantology. Titanium is considered a hard-to-cut material, because it develops high stresses and temperatures in a small cutting area (2/3 smaller than for other materials). Thus cutting parameters and tools need to be specified properly, since both raw material and manufacturing process increase the costs of the final product. This research determined the effects of cutting speed and depth of cut on machinability (cutting force and specific cutting energy) and surface integrity (microhardness and roughness) when threading pure commercially dental implants (grade 4, ASTM F67). Machining tests were carried out in a CNC lathe by applying TiAlN coated carbides and cutting fluid. Based on Analysis of Variance (ANOVA), the main results indicated that cutting parameters influence on machinability and surface integrity of the implant screw, being depth of cut the more influent. Low and high levels of depth of cut increase specific cutting energy and cutting force, respectively, hardening the screw subsurface and damaging the roughness of the thread flanks. Lower cutting speeds trend to raise both cutting force and specific cutting energy, damaging the screw finishing, but they do not affect its subsurface microhardness. Skewness and Kurtosis roughness parameters indicated the predominance of spiky surface on screw which is favorable to osseointegration. Tests at High-Speed Cutting (HSC) showed it is possible to machine implant screws, but depth of cut cannot be high so that avoiding vibration in threads / Mestre

In this study, five deaf individuals with cochlear implants were presented with noise that was manipulated systematically, to test the hypothesis that deaf persons using cochlear prostheses will demonstrate intensity regulation of their vocal output that is more appropriate when their implants are turned on than when turned off. The intensity of their vocal output was measured to determine if they demonstrated a Lombard response, that is, a systematic increase in vocal intensity with increasing intensity of background noise. Results from the study were mixed. With implants on, three subjects made systematic increases in vocal intensity with increasing background noise, while two subjects did not make such increases. In addition, the relation between intensity of vocal output and background noise was closer to the normal function for the three subjects who demonstrated a Lombard response. The "normal function" was defined by measuring the vocal intensity responses of five normal hearing control subjects who performed the same tasks as the experimental subjects.

Children with cochlear implants (CIs) typically have smaller lexicons in relation to their same-age hearing peers. There is also evidence that children with CIs show slower rates of vocabulary growth compared to hearing children. To understand why children with CIs have smaller vocabularies, we proposed to investigate their word learning process and determine how it compares to children with normal hearing. The present study explores multiple aspects of word learning - acquisition, extension, and retention - to better inform us about the real-world process of lexical acquisition in children with CIs. We evaluated 24 children with cochlear implants, 24 children with normal hearing matched by chronological age, and 23 children with normal hearing who were matched by vocabulary size. Participants were trained and tested on a word learning task that incorporated fast mapping, word extension, and word retention over two days. We also administered a battery of tests that included measures of receptive vocabulary and speech perception skills to determine which variables might be significant predictors of fast mapping and word retention. Children with CIs performed more poorly on word learning measures compared to their age-mates, but similarly to their vocabulary-mates. These findings indicate that children with CIs experience a reduced ability to initially form word-referent pairs, as well as extend and retain these pairs over time, in relation to their same-age hearing peers. Additionally, hearing age-mates and vocabulary-mates showed enhancement in their production of novel words over time, while the CI group maintained performance. Thus, children with CIs may not take the same route in learning new words as typically-developing children. These results could help explain, in part, why this population consistently demonstrates slower rates of vocabulary learning over time. Furthermore, we expected that speech perception and vocabulary size would relate to variations in fast mapping, as well as word retention. Neither of these variables proved to be significant predictors of fast mapping, but they were highly significant for word retention. Based on these findings, we may conclude that the factors that account for acquiring that first link between a word and its referent are not the same as those that are important for storing in a word in long-term memory.

The clinical success of Total Hip Arthroplasty is enhanced by matching hip implant geometry to femoral geometry. Traditionally, the shapes of hip implant designs have been based on data collected from patient populations using X-ray, CT Scan, digitized sliced bone, and other physical methods. The morphology of interest and the frame of reference often vary across researchers and the resulting numeric data are difficult to use in a Computer Aided Design package to build an implant model. This goal of this thesis was to develop procedures and automated programs for the design and evaluation of femoral hip implants using CT data. The procedures bridge the gap between patient specific "custom" prosthesis design and the so-called "averaged femur" implant designs. By automating the measurement, orientation and averaging of any user selected grouping of femora, these programs allow construction of an average femur template for small subsets of a population or populations. The programs allow grouping of femora using either dimensional attributes and/or patient attributes such as pathology, ethnic background, etc. The average femur template created for each group can then be used as the design boundary for a discrete implant size. Additional functionality is also provided for comparing average femur templates to their constitutive femora and for comparison of average femur templates against each other. To illustrate that the goals of this theses were realized, an example of the use of the system for a population of 192 Japanese is included in this thesis. The criteria for evaluation of the average femur templates was the gap or interference of the template to that of each constitutive femur along the medial and lateral endosteal contours. Testing 24 template sizes, the average of the worst fitting template to femur combination for each size resulted in a gap or interference of less than 2mm in the metaphysis and less than 4mm proximally.

Master of Dental Surgery / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Patients who suffer from severe joint destruction caused by arthritis often undergo total joint arthroplasty (TJA). A major limitation of this treatment and common long-term complication is the development of aseptic loosening of the prosthesis in as many as 20% of patients. The current paradigm to explain aseptic loosening proposes that wear debris generated from the prosthesis initiates a macrophage-mediated inflammatory response by resident macrophages, leading to osteoclast activation and bone resorption at the implant interface. This can then lead to the development of a peri-prosthetic fracture. The principal aim of fracture healing is to restore the bone to its original form and strength. However, this ultimate goal can be altered if the healing is impaired. This impairment may be due to bone disease (osteoporosis) or even the introduction of a foreign material such as PE wear debris that could have migrated from the articulating surface to the fracture site. A standard closed unilateral fracture of the right femur was performed in both normal and oestrogen deficient rats following fixation with a k-wire. Ceridust (PE wear debris) was combined with hyaluronic acid and saline and injected directly into the fracture site. Femurs were assessed using radiographs, histology and immunohistochemistry. Histological analysis revealed that complete remodelling was achieved in all control groups by 6 weeks post-fracture with mechanical strength returning to normal values. The mechanical properties of the fractures were not influenced by the presence of PE wear debris in the dose and timing examined. Histology and immunohistochemistry however, did reveal a local effect of the presence of PE wear debris. The histology adjacent to the PE particles was inferior to the controls but did not manifest itself in a reduction in the mechanical properties except in the oestrogen deficient bone at 6 weeks post-fracture. The levels of MMP-1 and TNF-?? correlated to the presence of PE particles. In this thesis, I have shown the mechanism by which bone remodelling in fracture healing could be retarded due to the presence of PE wear debris, by increased matrix degradation in both normal and oestrogen deficient animals.