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Guimarães, Maria Rosa Felix de Sousa Gomide [UNESP]. "Reparo ósseo de defeitos cirúrgicos críticos preenchidos ou não com ß – fosfato tricálcio (RTR® – Septodont): estudo histológico e histométrico em tíbias de ratos." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144731.
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Objetivos: Analisar histologicamente e histometricamente o efeito do RTR® em defeitos ósseos cirúrgicos críticos em tíbias de ratos no processo de reparo ósseo. Materiais e Métodos: Defeitos ósseos críticos foram criados nas tíbias de 32 ratos Wistar divididos em dois grupos: Grupo Coágulo e Grupo RTR®. Após o período experimental de 30 e 90 dias, os animais foram sacrificados e as peças incluídas em parafina, cortadas e coradas com hematoxilina e eosina. Dois parâmetros foram analisados: a área óssea total neoformada (AON) e a área óssea da cortical neoformada (ACN). A análise estatística foi realizada nos dois períodos de observação pela análise de variância (ANOVA) e pelo Teste de Tukey. Resultados: Todos os grupos demonstraram reparo ósseo superior quando comparados ao Grupo Coágulo 30 dias nos dois parâmetros analisados. O Grupo RTR®, em 30 e 90 dias, apresentou reparo da cortical óssea e formações de tecido ósseo na região central do defeito maior do que no Grupo Coágulo de 90 dias, que apresentou reparo parcial da cortical óssea e poucas formações de tecido ósseo na região do defeito (p<0,05). Conclusões: O RTR® favoreceu a neoformação óssea no modelo experimental adotado podendo ser indicado em casos de cavidades ósseas de tamanho crítico.
Objectives: To analyze histologically and histometrically the effect of RTR® on critical surgical bone defects in rat tibiae in the bone repair process. Materials and Methods: Critical bone defects were created in the tibia of 32 Wistar rats divided into two groups: Clot Group and RTR® Group. After the experimental period of 30 and 90 days, the animals were sacrificed and the paraffin embedded pieces were cut and stained with hematoxylin and eosin. Two parameters were analyzed: total neoformed bone area (AON) and bone area of neoformed cortical (ACN). Statistical analysis was performed in the two observation periods by analysis of variance (ANOVA) and Tukey's test. Results: All groups demonstrated superior bone repair when compared to the Clot Group 30 days in the two analyzed parameters. The RTR® Group, in 30 and 90 days, presented repair of the cortical bone and bone tissue formations in the central region of the defect greater than in the 90-day Clot Group, which presented partial repair of the cortical bone and few bone tissue formations in the region of the defect (p <0.05). Conclusions: The RTR® favored the bone neoformation in the adopted experimental model and can be indicated in cases of bone of critical size.
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Samizadeh, S. "Bone formation on calcium phosphate bone substitute materials." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/19891/.
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A large number of bone substitute materials are available; for which some authors claim osteoconductivity and some osteoinductivity. In order to rank these materials an in vivo analysis was carried out. These materials were chosen based on their availability and claimed mode of action. Silicon substituted Hydroxyapatite (SiHA), Hydroxyapatite (HA), Resorbable Calcium Phosphate Silicon, Skelite [siliconstabilized tricalcium phosphate-based bone substitute], Pro Osteon 500R [coralline HA], BiIonic [Yttrium stabilized SiHA] and two non-calcium phosphate, Dimeneralised Bone Matrix (DBM) based biomaterials: Accell Connexus DBM putty and Grafton crunch DBM were implanted in sheep femoral condyle defects for 6 weeks. Implanted calcium phosphate (CaP) based biomaterials demonstrated superior bone formation in comparison with the DBM samples. Silicon within CaPs increased the rate of bone formation in vivo. Silicon substituted HA showed increased proliferation rate (P<0.05) of human marrow stromal cells compared to pure HA in vitro. Expression of osteoblastic marker genes RUNX2, Osterix and Osteopontin within the hMSCs indicated the differentiation of preosteoblasts into osteoblasts, and osteogenic development on both HA and SiHA. Expression of osteocalcin and bone sialoprotein genes on HA and SiHA samples indicated the activation of mineralisation process. Differentiation of hMSCs into osteoblasts in vitro suggested a role in promotion of osteoinduction by both HA and SiHA. Implantation of porous SiHA and HA in paraspinous muscle of sheep, exhibited new bone formation through osteoinduction. SiHA indicated significantly higher new bone formation (P<0.01) compared to HA. SiHA and HA biomaterials with higher strut porosity (30%) indicated greater bone formation (P<0.05). In conclusion, CaP based biomaterials demonstrate superior bone formation in comparison with DBM biomaterials. Silicon substitution within HA enhances the cellular activity of hMSCs. Osteoinduction was greatest on SiHA with higher strut porosity. This result is believed to be due to a combination of the effect of interconnected porosity and chemical composition of the bone substitute.
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Öberg, Sven. "Bone healing after implantation of bone substitute materials : experimental studies in estrogen deficiency /." Umeå : Univ, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-138.
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Bonardi, João Paulo. "Estudo comparativo entre o ChronOs® e o Bio-Oss® em procedimentos de elevação da membrana sinusal em seios maxilares de humanos : análise histométrica e imunoistoquímica /." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/148947.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Objetivos: Comparar através de análise hitométrica e imunoistoquimica o comportamento do ChronOs® (β-TCP) e do Bio-Oss® (Osso bovino inorgânico ) puros e misturados ao osso autógeno na proporção 1:1 em seios maxilares de humanos. Metodologia: 30 pacientes foram convidados para participar deste trabalho, resultando em 30 seios enxertados com osso autógeno puro (grupo A (controle)), ChronOs® puro (grupo C), ChronOs® em adição de osso autógeno na proporção 1:1(grupo CA), Bio-Oss® puro (grupo B) e Bio-Oss® em adição de osso autógeno na proporção de 1:1 (grupo BA), onde foram realizadas biopsias 6 meses após a realização desses enxertos e analisadas através de histometria (analisadas através do software ImageJ) e imunoistoquimica (RUNX2, VEGF e Osteocalcina). Os resultados foram tabulados, o teste de Shapiro-Wilk foi aplicado para avaliação da normalidade, em seguida foram aplicado os testes Kruskal-Wallis e Anova 1 fator para os dados paramétricos e não paramétricos sucetivamente e o teste de Tukey como pós teste. Resultados: Para neoformação óssea o grupo A foi maior que os grupos B e BA e o grupo CA foi maior que o grupo BA (p<0,05). Para os remanescentes de biomateriais o grupo BA apresentou um número maior que os grupos Chronos C, CA e A (p<0,05). Para tecido mole o grupo C foi maior que o grupo B (p<0,05). O resultado das imunomarcações mostrou marcação fraca para RUNX 2 nos grupos A, C, B e BA e marcação moderada para o grupo CA. Marcação intensa para VEGF nos grupos B e CA, moderada nos grupos A e C e fraca no grupo BA. Para a Osteocalcina houve uma marcação intensa em todos os grupos. Conclusão: Conclui-se que o Chronos puro ou misturado apresentam comportamento mais próximo ao osso autógeno em termos de quantidade de tecido ósseo neoformado e remanescentes de biomateriais que o Bio Oss puro ou associado ao osso autógeno.
Objectives: To compare the performance of ChronOs® (β-TCP) and Bio-Oss® (Inorganic bovine bone) pure and mixed with autogenous bone in a 1: 1 ratio in maxillary sinuses of humans through histometric and immunohistochemical analysis. Metodology: 30 patients were invited to participate of this study, resulting in 30 grafted sinuses with pure autogenous bone (group A (control)), pure ChronOs® (group C), ChronOs® in addition 1: 1 autogenous bone (group CA), pure Bio-Oss®(group B) and Bio-Oss® in addition1: 1 (group BA), which biopsies were performed 6 months after the grafting and analyzed by histology (analyzed using ImageJ software) and immunohistochemistry (RUNX2, VEGF and Osteocalcin). The results were tabulated, the Shapiro-Wilk test was applied to evaluate the normality, then the Kruskal-Wallis and Anova 1 tests were applied for the parametric and non-parametric data and Tukey test as post test was applied. Results: The group A was higher than B and BA groups, and the group CA was higher than the BA group (P <0.05). For the remainder of biomaterials, BA group presented a higher number than Chronos C, CA and A groups (P <0.05). For soft tissue, group C was greater than group B (P <0.05). The immunolabeling results showed poor labeling for RUNX 2 in groups A, C, B and BA and moderate labeling for CA group. Intense labeling for VEGF in B and CA groups, moderate in groups A and C and weak in BA group. For Osteocalcin, there was an intense marking in all groups. Conclusion: It was concluded that pure or mixed Chronos present behavior closer to the autogenous bone in terms of amount of neoformed bone tissue and biomaterial remnants than the pure or mixed Bio Oss.
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Simpson, Rebecca Louise. "Design of a bone substitute material." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/11534.
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Al-Bader, Yousef A. "Development of a piezoelectric bone substitute material." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249905.
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Hilal, M. K. "Development of a high strength bioactive bone substitute." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267175.
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Öberg, Sven. "Bone Healing after implantation of bone substitute materials. Experimental studies in estrogen deficiency." Doctoral thesis, Umeå University, Odontology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-138.
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Bone formation and bone healing were studied in the mandible, tibia and skull bones in adult, healthy and estrogen deficient rabbits implanted with different bone substitutes.
In the first study an evaluation of the differences in bone regeneration in and around solid (Alveograf *) and porous hydroxyapatite (Interpore 200*) was undertaken. The implant material was placed into experimentally made bone defects and in half of the defects hydroxyapatite was mixed with a fibrin sealant (Tisseel *). The material alone or mixed with Tisseel was also placed subperiostally in the mandible. The observation time was six month. No difference in bone regeneration was found between solid or porous hydroxyapatite granulas and the addition of Tisseel* did not seem to disturb the bone healing process. The implant material placed subperiostally did not induce bone formation nor did it provoke any bone resorption. The addition of Tisseel made the implant material much easier to handle and retain in the tissue during surgery.
Bone healing around hydroxyapatite implants was also evaluated in the second study. Experimental cavities in the mandible and tibia were filled with hydroxyapatite in granules or blocks (Interpore 200*) but now with or without autolyzed, antigen-extracted, allogeneic bone (AAA). Also in this study Tisseel* was used to facilitate the handling of the material. All cavities implanted with AAA-bone, regardless of the combination with hydroxyapatite or Tisseel, demonstrated excessive bone formation resembling exostosis formation. Thus, hydroxyapatite, both as granules and blocks, can be successfully combined with AAA bone utilizing the bone inductive capacity of AAA bone.
The same model was used to study the healing in ovariectomized animals in the third study. Bone cavities were implanted with or without AAA bone and left to heal. The results indicate that the osteoinductive capacity of AAA bone is in operation also in animals deprived of a normal estrogen production.
The effect of using AAA bone prior to implant insertion was studied in paper four. The bone-implant contact was significant higher when AAA bone had been used. The implant stability did not seem to be affected.
In paper five defects were made in skull and tibial bone in estrogen deficient animals. The deficiency of estrogen was confirmed through blood analysis, the decrease in the weight of uterus and bone mineral density. The whole body scanning with DEXA showed that the ovariectomized animals developed osteopenia. Various degree of bone formation was seen in the defects due to the influence of the bone inductive substance AAA bone.
The studies indicate that a conductive material like hydroxyapatite in granules or blocks could be useful in oral reconstructive surgery. The combination with AAA bone enhanced the bone formation in calvarial and tibial bone in healthy and estrogen deficient animals. Tisseel* could be used to facilitate handling and retention of the material in the intended position during the healing process without negative effects.
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Alfayez, Eman Saud. "Synergizing angiogenesis and osteogenesis in a smart bone substitute." Thesis, King's College London (University of London), 2016. https://kclpure.kcl.ac.uk/portal/en/theses/synergizing-angiogenesis-and-osteogenesis-in-a-smart-bone-substitute(ad38b2b9-e1e3-42ce-88a0-91a764bc14e6).html.
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The major aim of this project was to develop a biologically active bone scaffold that could induce vascularization in critical-size defects (CSD) and hence bone formation. In this study, functionalization of three-dimensional (3D) printed biphasic calcium phosphate (BCP) scaffolds was investigated. The first functionalization approach involved printing scaffolds with two different pore geometries and sizes; square (400μ) and round (800μ). The second was by coating scaffolds with DAR16-II; a self-assembly peptide that forms a hydrogel nanostructure mimicking extracellular matrix (ECM). A rabbit model was used to study these functionalization methods; square and round pore scaffolds with and without DAR16-II coating were implanted into experimental rabbit calvaria bone CSD defects. After 8 weeks, animals were killed and tissue was processed for histomorphometric analysis. Histological evaluation showed that bone formation was pore size and geometry independent while DAR16-II was successful in inducing bone formation compared to non-coated scaffolds. The following in vitro studies aimed towards understanding the basic cell response that enhanced bone formation in vivo. Human mesenchymal stem cells (MSCs) were used to identify the osteogenic potential of DAR16-II. Molecular analysis and mineralization staining showed that DAR16-II lacks osteoinductive properties. However, DAR16-II preserved cell viability when used as a BCP coating in vitro. In addition, DAR16-II exhibited angiogenic potential upon culturing with human umbilical vein endothelial cells (HUVECs) in vitro. DAR16-II induced the spreading of endothelial cells, activation and tubular-structure formation. Angiogenesis Real time-2 (RT2) polymerase chain reaction (PCR) array was used for gene expression analysis and showed that DAR16-II angiogenic effect was regulated by overexpression of endoglin (ENG or CD105), a clade E member of the serine protease inhibitor-1 (SERPIN-1) and β-Actin (ACTB) and down-regulation of VEGF receptor I (Flt1) and VEGF receptor II (KDR) Flt1. Furthermore, DAR16-II enhanced attachment of monocyte THP-1 cells. Results have demonstrated that DAR16-II add a proactive factor to BCP scaffolds. The proposed functionalization methodology increases the potential of enhancing vascularization and bone formation within ceramic scaffolds.
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Abbah, Sunny Akogwu. "Towards an injectable bone graft substitute: evaluation of sodium alginate microcapsules for bone tissueengineering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B39329951.
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Lawson, Alison C. "Collagen-calcium phosphate composites." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300895.
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Corrand, Didier M. "The effects of some biochemicals on the precipitation behaviour of hydroxylapatite." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267950.
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Abbah, Sunny Akogwu. "Towards an injectable bone graft substitute evaluation of sodium alginate microcapsules for bone tissue engineering /." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B39329951.
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Swanprateeb, Jintamai. "Creep behaviour of hydroxyapatite reinforced polythylene composites." Thesis, Queen Mary, University of London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307513.
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Mladenovic, Zivko. "Biological interface of bone graft substitute materials : experimental studies on interactions between biomaterials and bone cells." Doctoral thesis, Umeå universitet, Institutionen för odontologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-49818.
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Bone graft substitute materials are becoming more common as alternative therapy strategies when bone defects in patients need to be treated. The interaction between bone cells and biomaterials occur at the surface of the materials. A great deal is known about the importance of surface topography and physic-chemical properties of biomaterials. It is also known that cells require proteins in order to interact with biomaterials. Less is known about how material properties and proteins interact forming the biological interface that cells will be exposed to, and that might determine if new bone is formed or not in the patient. The overall aim of the present thesis was to systematically investigate bone graft substitute material surface reactions and the interface in order to better understand how biomaterials may promote bone formation. Bio-Oss (BO) is a commonly used bone graft substitute material in reconstruction of periodontal and dentoalveolar bone defects. BO is mainly considered to be “osteoconductive”, but we could show that it does interact with a biological fluid (α-MEM cell culture medium) through dissolution/precipitation reactions. A significant reduction of calcium and phosphate levels in the medium was obtained even with low concentrations of BO. A release of silicon from the material was also demonstrated. An osteogenic response was seen in close contact to the BO particles when cultured with different types of pre-osteoblastic cells (Paper I). X-Ray Photoelectron Spectroscopy (XPS) with fast-frozen sample technique was used to further characterize the surface of BO, Frios Algipore (AP) and 45S5 Bioglass (BG). These three bone graft substitute materials are used as “model systems”, because they have all demonstrated newly formed bone on the surface after implantation in patients. From the XPS analysis it can be concluded that AP and BG acquired a positively charged surface while BO gained a negatively charged surface. Only AP and BG adsorb organic components (amino acids) from the medium (Paper II). Next we investigated initial surface reactions and the formation of a biological interface in the presence of proteins (serum) for the three biomaterials. The major findings were that in the presence of proteins BO underwent a surface charge reversal, all three biomaterials adsorbed proteins on the surface and all three biomaterials altered the chemical composition of the cell culture medium (Paper III-IV). Silicon (Si), which was released from BO as well as from BG, is interesting in relation to bone health. Positive effects of BG Si dissolution products on osteoblasts have been reported earlier. In the present study inhibitory interactions of Si on the RANK/RANKL/OPG signaling pathway as well as with gap junction intercellular communication in vitro are reported. These new findings implicate that Si could potentially be beneficial for patients with imbalance in bone remodeling (osteoporosis) and treatments of bone defects (Paper V). In conclusion, biomaterials of different origins interact with a solution resembling the extracellular tissue fluid. The dissolution-precipitation reactions are influenced by the material concentration used and should be taken into consideration when designing experiments and when biomaterials are used clinically. The presence of proteins will influence surface reactions, the formation of the biological interface and have implications on cellular responses. Possible dissolution products from the biomaterials should be investigated. Si, a dissolution product, is shown to have an inhibitory effect on osteoclastogenesis and bone resorption in vitro. Potential clinical value of Si in treatment of patients with bone defects should be further investigated.
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Al-Harkan, Abdullah. "Is Bio-Oss an osteoconductive material when used as an onlay bone substitute? : an experimental study in the mandible of the rabbit." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112372.
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The present study was carried out to evaluate the osteoconductive nature of Bio-OssRTM (natural deproteinized bone mineral) when used as an onlay bone substitute in a Guided Bone Regeneration model. The lateral surface of the mandible was exposed bilaterally, in 8 rabbits. On one side of the mandible, two titanium chambers were filled with Bio-OssRTM material and the chambers were then firmly secured to the mandible using screws. The pores in the titanium chambers were covered with a layer of Bio-GideRTM material. On the opposite side of the mandible, chambers without Bio-OssRTM were placed on the lateral side of the mandible as a control. After a healing period of 3 months, histologic sections were obtained from each chamber. It was observed that new bone was generated in both test and control chambers to various degrees. In the test group, the newly generated bone was 18.41% and in the control group it was 5.31%. This difference was statistically significant. Thus, in this experiment, Bio-OssRTM was proven to be osteoconductive.
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Chan, Kwok-ming, and 陳國明. "To develop a transplantable viable construct for the patching of a bone defect: a new bone graft substitute bymeans of tissue engineering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50533873.
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Bone grafting is an integral part of reconstructive surgery. In the United States alone over 250,000 bone grafts were harvested annually. While autogenic bone grafting has always been associated with donor site morbidity, bone graft substitutes have been suggested as a solution. In this project, a bone graft substitute using human dental pulp cells (HDPCs) and peptide nanofibre hydrogel was being developed.
HDPCs were isolated from extracted teeth. After culture and expansion, unsorted HDPCs were encapsulated into peptide nanofibre hydrogel. These cell-gel constructs were cultured for two weeks in ordinary culture medium and then for 2-3 more weeks in osteogenic lineage induction medium. The post-induced cell-gel derived constructs were transplanted into skin pouches or calvarial bone defects of nude mice.
When transplanted subcutaneously, the cell-gel derived constructs were harvested at four to twelve weeks postoperatively (n=5). Tissue samples were processed for contact radiograph, histological examination and antibody staining. These constructs developed into vascularised, mineralised tissue pieces. Though bone marker proteins (osteopontin, osteocalcin and osteonectin) were detected in these tissue pieces, the histological structure of their tissue matrix did not resemble bone matrix.
Later, it was accidentally noted that portions of constructs touching the bone defect margin, would form bone through direct matrix transformation. This indicated that the current cell-gel model was potentially the first study model of tissue engineering bone by simulating intramembranous ossification.
In the bone defect trial, obviously mineralized cell-gel derived constructs of matching shape and size were selected to patch the 3mm calvarial bone defects (n=5). Bone defect specimens were harvested at two weeks post-operation. The development of radio-opaque structures within the bone defects were evaluated in virtual 3-dimensional models constructed with data collected by microtomographic scanning. The bone nature of these radio-opaque structure were validated histologically (by staining with Hematoxylin and Eosin, Periodic acid-Schiff stain and Picrosirius red) and immunologically (with antibody against human collagen-I, osteonectin and parathyroid hormone receptor). The radio-opaque structures developed into the bone defect were evaluated positive for bone. And significantly more bone regeneration was observed in the test group (n=4) than in the control (n=2). The mean area percentages of regeneration were 46.3% and 0% respectively (p< 0.05).
While the majority of studies in bone tissue engineering have worked with bone marrow stromal cells and scaffolds of synthetic polymer or calcium based materials, this is the first successful attempt of using HDPCs and peptide nanofibre hydrogel to engineer bone (in a nude mice mode). And the potential of these cell-gel derived constructs to promote bone regeneration was demonstrated.
But this was the result from a single experiment of small sample size in one animal model only. It needs to be fortified by further experiments with larger population size and in other animal models.
To increase clinical usefulness, the construct will need to be scaled up to centimetre size level. This will necessitate a change of its configuration from bead into meshwork. And, the data collected to date will shed light onto the redevelopment of all the relevant protocols.published_or_final_version
Dentistry
Doctoral
Doctor of Philosophy
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Ramírez, Caballero Silvia. "Composites made of bioceramic and chitosan physical hydrogel as potential bone substitutes." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI010/document.
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Les substituts osseux synthétiques servent au remplacement temporaire des tissus osseux, favorisent la formation, la croissance et la survie de l’os et sont biorésorbables. Aucun matériau monophasé ne remplissant complètement ces exigences, un matériau composite bioinspiré est une alternative possible. L’objectif de cette thèse était par conséquent d’étudier la synthèse et les propriétés de deux composites biocéramiques/biopolymères : des hydrogels physiques de chitosane minéralisés avec de l’apatite, et une hardystonite architecturée imprégnée par des hydrogels physiques de chitosane. Afin d’obtenir le premier matériau, deux approches ont été développées. La première a consisté à fabriquer des hydrogels physiques de chitosane puis à les minéraliser avec de l’apatite ; la formation de microcapillaires se produit avec des conditions de synthèse spécifiques, et les précipités d’apatite ont été trouvés uniquement à la surface des hydrogels. La seconde approche consiste à convertir des suspensions homogènes contenant le phosphate de calcium et le chitosane en hydrogels de chitosane minéralisés par l’apatite. Les suspensions ont été préparées soit avec un mélange simultané, soit avec des mélanges successifs de suspensions phosphates de calcium avec les solutions de chitosane. Des agrégats minéraux plus petits avec une distribution plus uniforme ont été formés avec la méthode des mélanges successifs. Cela est attribué à une meilleure homogénéité, une viscosité plus faible et l’absence de chitosane. De manière générale, trois paramètres influencent les propriétés mécaniques d’hydrogels de chitosane minéralisés : la base utilisée pour la gélification (déterminant la vitesse de gélification : une grande vitesse conserve l’enchevêtrement des chaînes, résultant en une meilleure élasticité) ; la densité de la réticulation physique (cela induit un module de conservation plus important) et la force ionique (qui mène au désenchevêtrement des chaînes de chitosane, donc, à un faible module de conservation). Cette compréhension a permis l’utilisation de ces suspensions de phosphate de calcium-chitosane en tant qu’encre pour l’impression 3D. Les hydrogels de chitosane et les hydrogels minéralisés ne sont pas cytotoxiques. Pour fabriquer le second matériau, une encre pré-céramique a été imprimée en 3D puis frittée pour former une céramique d’hardystonite cristalline. Les scaffolds d’hardystonite ont été imprégnés par la solution de chitosane, converties ensuite en hydrogels physiques de chitosane. A plus forte concentration de chitosane, la viscosité de la solution était plus grande et l’imprégnation de la matrice plus lente. Avec une vitesse de gélification plus importante, qui dépend de la base utilisée pour la gélification, la perte de poids est plus faible pendant la gélification. L’hydrogel de chitosane a partiellement rempli les pores participant au support de charges externes et à la dissipation d’énergie par ruptureBone substitutes, an approach to attend social demand for bone healing and reparation, are temporary replacements of bone tissue, promote bone formation and growth and finally are bioresorbed. No single material meets these requirements; an alternative is a bioinspired composite material. The objective of this thesis was thus to study the synthesis and properties of two bioceramics/biopolymer composites: chitosan physical hydrogels mineralized with apatite and hardystonite scaffolds impregnated with chitosan physical hydrogels. To obtain the first material, two strategies were developed. The first one consisted in the fabrication of chitosan physical hydrogels and its subsequent mineralization with apatite; the formation of micro-capillaries occurred under particular synthesis conditions, and apatite precipitates were found only on the surface of hydrogels. The second strategy consisted in a simultaneous conversion of chitosan-calcium phosphate suspensions into chitosan-apatite hydrogels. The suspensions were prepared by sequential or simultaneous mixing of calcium and phosphate suspensions with chitosan solutions. Smaller and more uniformly distributed mineral aggregates were formed following sequential mixing, attributed to higher homogeneity, lower viscosity and no-presence of chitosan. This enabled the use of these chitosan-calcium phosphate suspensions as inks for 3-D printing. In general, three factors impacted the mechanical properties of mineralized chitosan hydrogels: the base used for gelation (determining the gelation rate: a higher rate preserved chain entanglement, resulting in higher elasticity); the density of physical crosslinks (hence a higher storage modulus) and the ionic strength (that led to chitosan chain disentanglements, thus, low storage modulus). Chitosan hydrogels and mineralized hydrogels were not cytotoxic, having no deleterious effects on osteoblasts proliferation. To fabricate the second material, pre-ceramic ink was 3-D printed and then sintered to form crystalline hardystonite ceramic. Hardystonite scaffolds were impregnated with chitosan solution that was, next, converted to chitosan physical hydrogel. At higher chitosan concentration, viscosity of solution was higher and scaffold impregnation was lower. At higher gelation rate, which depend on base used for gelation, lower weight loss during gelation. Chitosan hydrogel partially filled the pores contributing to bearing of external loads and to energy dissipated by fracture
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Brown, Matthew E. "DEVELOPMENT OF A MOLDABLE COMPOSITE BONE GRAFT SUBSTITUTE RELEASING ANTIBACTERIAL AND OSTEOGENIC DRUGS." UKnowledge, 2014. http://uknowledge.uky.edu/cbme_etds/17.
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Large infected bone defects (IBD) are very complicated to treat due to their high variability; they often require multiple procedures. Bone autografts are the gold standard for treatment but have several drawbacks, such as a need for a second surgery site, limited grafting material, and donor site morbidity. The objective of this research was to develop a moldable synthetic bone grafting material capable of releasing both antimicrobial and osteogenic drugs over a clinically relevant time course for the treatment of IBDs. Current treatment methods for large IBDs require two separate procedures to treat the bone defect and the infection.
This research sought to combine these two procedures into one implantable composite bone graft substitute for the treatment IBDs. To begin, the degradation and mechanical properties of the calcium sulfate (CS) based composite material were evaluated for different compositions. Next, the controlled drug release profiles from the composite was achieved by using a shell and core system incorporating poly(lactic-co-glycolic acid) microspheres (PLGAms). The release of vancomycin from the shell began immediately and continued over the course of 6 weeks, while the release of simvastatin from the core was delayed before being released over 4 weeks. Next, an infected, critically-sized rat femoral defect model was used to test different treatment methods with and without the composite bone graft substitute. Animals treated with locally released antibiotics had survivorship rates 24% higher than those treated with systemic antibiotics, and animals that received both antibiotics and an osteogenic drug had an increased amount of bone formation at 12 weeks compared to controls.
Finally, several different anti-biofilm agents were evaluated for their ability to inhibit and/or disrupt the growth of Staphylococcus aureus (S. aureus) biofilms in vitro. Lysostaphin was the only drug investigated that was able to both inhibit and disrupt S. aureus biofilms. Furthermore, lysostaphin encapsulated into PLGAms maintained its bioactivity and may be useful for future incorporation into biofilm-combating materials. The bone grafting material developed here can be used to locally deliver drugs in a temporally controlled manner to reduce the number of procedures necessary for the treatment of complex IBDs.
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Kent, Niall William. "Development of a novel in-vivo setting bone graft substitute from bioactive glass." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8442.
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Calcium phosphate cements are in-vivo setting, injectable calcium phosphate based biomaterials. They are made of calcium phosphate salts which when mixed with water react to form apatite, the mineral phase of bones and teeth. This study investigates a novel way of forming calcium phosphate cements using bioactive glasses. The aim of the work was to discover a novel route of synthesis using a silicate bioactive glass. Fifteen glass compositions were produced designed to investigate P2O5 content, CaF2 content and calcium to sodium ratio within the glass. Glasses were produced via a melt-quench route before being milled and sieved to below 38 μm. The bioactive glass and Ca(H2PO4)2 powders were mixed in an overall calcium to phosphate ratio of 1.67. The cement powder was then reacted with a 2.5 % solution of Na2HPO4. The paste was then mixed and then placed into cylindrical moulds. Eight samples were immersed into Tris buffer solution for 1 hour, 1 day, 7 days or 28 days. The compressive strength was measured for each specimen as well as SEM performed and the setting times for each composition was studied using the Gilmore needle test. The cement phase was analysed using 31P & 19F MAS-NMR, FTIR and XRD. The results showed that both compressive strength and setting time was dependent upon glass composition. As sodium content was increased both the initial and final setting times decreased. Increased fluoride addition caused a decrease in the setting time. In the fluoride free compositions octacalcium phosphate was identified in all compositions. The cement setting reaction for these compositions followed a similar reaction of first forming dicalcium phosphate dihydrate which transformed to octacalcium phosphate then eventually hydrolysing to hydroxyapatite. When fluoride was incorporated into the cement the phases formed were fluoridated-apatite and DCPD. In conclusion a novel method of producing calcium phosphate cements was discovered using a bioactive glass as a reactive precursor. It was shown that the cement phase, setting time and compressive strength could all be altered by changing the glass composition.
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Sándor, G. K. (George Kálmán Béla). "The minimization of morbidity in cranio-maxillofacial osseous reconstruction:bone graft harvesting and coral-derived granules as a bone graft substitute." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514269640.
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Abstract
Reduction of morbidity in osseous reconstruction of cranio-maxillofacial bony defects could come from development of less invasive bone graft harvesting techniques or by elimination of bone graft donor sites using a bone graft substitute. This work studies outcomes and morbidity associated with these two approaches.
A power-driven trephine was used to harvest bone from the anterior iliac crest using a minimally invasive surgical technique. Initially the safety of the technique was evaluated in a cadaver model. Twenty-five freshly preserved adult cadavers had a total of 250 cancellous cores of bone harvested from 50 anterior iliac crest sites. Twenty intentional perforations were made to the maximum depth possible with the instrumentation tested. No encroachment upon the peritoneum was found.
A total of 84 patients had 333 cores of cancellous bone harvested using the same approach with a complication rate of 3.6% and a patient satisfaction rate of 98.8%. In a further 76 patients the motorized trephine method was compared to traditional open iliac crest corticocancellous block harvesting. The trephine group ambulated earlier, required fewer days of hospital stay and had significantly lower pain scores than the open iliac crest group.
Coral-derived granules were used as a xenograft bone graft substitute to treat bony defects in the cranio-maxillofacial skeletons of 36 patients with 54 sites and followed for 12 to 36 months. The augmentations produced satisfactory results with the following complications noted: overt wound infection 1.8%, wound irritation 3.8% and clinically evident resorption in 9.3% of augmented sites.
Coral-derived granules were then used to treat 48 dento-alveolar defects in 21 growing patients with trauma induced tooth-loss in the anterior maxilla and elective ankylosed tooth removal in the posterior maxilla and mandible. Coral granules were significantly more efficacious in reconstructing alveolar defects in the posterior maxilla or mandible (93.5%), than the anterior maxilla (17.6%).
The minimally invasive technique using a power driven trephine was successful at reducing morbidity from bone graft harvesting at the anterior iliac crest. Coral-derived granules can be used in selected situations as a bone graft substitute and minimize post surgical morbidity by eliminating the bone graft donor site.
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Olsson, Mirja. "Chemical stability of grain boundariesin β-tricalcium phosphate ceramics : β-TCP as bone substitute material." Thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-173285.
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β – Tricalcium phosphate (β-TCP, Ca3(PO4)2) is a commonly used bone substitute material due to its biocompatibility and resorption. This study focused on the production of almost fully dense β-TCP ceramics with varying degrees of impurities (Ca/PO4 ratio, addition of 5% Mg). Three methods were used to produce the β-TCP ceramics, uniaxial pressing, slip-casting and isostatic pressing. In this study the isostatic pressing and sintering at 1150ºC for 20h and 15min, resulted in the densest β-TCP ceramics (97.7-99.2%). No significant differences of grain size and density could be detected between the samples produced with various compositions. These isostatically pressed samples sintered at 1150ºC were then dissolved in 0.08M aceticacid solution to simulate the in vivo resorption. It was found that the samples containing extra Mg dissolved slower. Attempts to determine the chemical composition of the grain boundaries were made without success. However, SEM observations of partly dissolved β-TCP ceramics revealed that the grain boundaries dissolved faster than the grains. The study was performed at the RMS foundation in Switzerland.
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Ziminska, Monika. "Templated layer-by-layer assembly of coated porous structures for a potential engineered bone substitute." Thesis, Queen's University Belfast, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.728841.
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The high mechanical properties and thickness of films fabricated with layer-by-layer (LbL) assembly combined with simplicity, versatility and low cost of the technique are worth exploring for an engineered bone substitute application. This research programme investigated the use of polymer-nanocomposite material system composed of polyethyleneimine (PEI), polyacrylic acid (PAA) and nanoclay (PEI/PAA/PEI/nanoclay) as means of coating 2D and 3D specimens with the aim to adapt LbL assembly to fabricate stiff and strong polymer-nanocomposite coatings onto an open-cell porous template that enables customisation of physical and mechanical properties of coated porous structures. Open-cell foams were coated with the PEI/PAA/PEI/nanoclay material system and demonstrated a general fabrication strategy of coating porous structures via LbL assembly. The architecture and physical properties of the foams evolved in a regular and predictable manner, with strut thickness and mass increasing, and cell size and porosity decreasing as the coating thickness increased. The work outlined in this thesis has shown that the physical (mass, thickness, porosity) and mechanical (compressive modulus, collapse stress) properties of coated templates can be tailored by changing the processing parameters during the coating deposition. The experimental data was compared with theoretical predictions to examine if this approach would be suitable for a potential bone substitute application. MG-63 and pBM-MSC cell lines had the ability to adhere and proliferate on the surface of 10-quadlayer coatings capped with PAA and thermally treated, suggesting that the LbL assembly coating is a promising candidate for an engineered bone scaffold substitute application. It is expected that the results of this study will serve as a guide for the design of engineered scaffold materials with compressive modulus and collapse stress comparable to that of cancellous bone tissue and allow for fabrication and customisation of stiff and strong porous materials for application such as sandwich panels or high-end packaging.
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Sanders, Lawrence Matthew. "The Synthesis & Characterization of an Antibacterial Bioactive Glass Suitable as a Bone Void Substitute." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo15447109069978.
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White, Brandon M. "Characterizing the Association Between Mandible Mechanical Properties and Function in the Rabbit." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1506426954676547.
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Mauro, Frank Armand. "Assessment of biodegradable calcium polyphosphate for bone substitute applications in the healing of the rat calvarium." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0004/MQ45973.pdf.
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Casey, Brian Paul. "Novel fabrication techniques for the production of porous biphasic calcium phosphate ceramics for bone substitute application." Thesis, University of Bath, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760834.
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Llanos, Alexandre Hugo. "Comparação das alterações dimensionais do rebordo alveolar pós-exodontia entre a técnica de preservação alveolar com a utilização de substituto ósseo xenógeno e a cicatrização espontânea: ensaio clínico aleatório." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/23/23146/tde-04042018-112542/.
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A cicatrização de um alvéolo após a extração dental é uma resposta reparadora. Após a exodontia, a cicatrização espontânea irá levar à perda do volume e do formato do rebordo original. A preservação alveolar envolve qualquer procedimento que limite os efeitos da reabsorção pós-extração. O objetivo deste estudo foi avaliar o uso de um substituto ósseo xenogênico na preservação alveolar pós-extração dental comparado com a cicatrização espontânea em dentes anteriores da maxila com defeitos ósseos da parede vestibular maiores do que 50%. Foram tratados 13 pacientes com necessidade de exodontia de dente anterior da maxila com perda >50% da parede vestibular. Todas as exodontias foram realizadas sem retalho. Os pacientes foram alocados aleatoriamente em grupo teste: preservação alveolar com substituto ósseo (7 participantes) e grupo controle: cicatrização espontânea (6 participantes). O desfecho primário foi a alteração dimensional do rebordo alveolar calculada entre as imagens tomográficas de início (pós-exodontia) e depois de 4 meses da intervenção, na espessura 1mm abaixo da porção coronal da crista (HW-1). Os desfechos secundários foram as medidas vestibular e palatina, e os segmentos transversais HW-3 e HW-5. A medida HW-1 reduziu 51,21 % no grupo teste e 82,80% no grupo controle, com uma diferença intergrupos estatisticamente significante de 31,59%. Para as medidas transversais, houve redução estatisticamente significante tanto para HW-3 quanto para HW-5 entre os dois grupos. Em alvéolos com perda da parede vestibular maior que 50%, a utilização do substituto ósseo promoveu uma menor perda horizontal na ordem de 30%.The healing process of post-extraction sockets is bone resorption. After tooth extraction, spontaneous healing will lead to loss of volume and shape of the original ridge. Alveolar ridge preservation involves any procedure that limits the effects of post-extraction resorption. The objective of this study was to evaluate the use of the xenogenic bone substitute in the post-extraction alveolar preservation compared to spontaneous healing in anterior maxilla teeth with vestibular wall defects greater than 50%. Thirteen patients with anterior maxillary tooth extraction with a > 50% buccal wall loss were treated. All the surgeries were made flapless. Patients were randomly assigned to a test group: alveolar preservation with bone substitute (7 participants); and control group: spontaneous healing (6 participants). The primary outcome was the dimensional alteration of the alveolar ridge calculated between the tomographic images at the beginning (post-extraction) and after 4 months of the intervention, at the thickness 1mm below the coronal portion of the crest (HW-1). Secondary outcomes were measures buccal and palatine, and HW-3 and HW-5 cross-sections. The HW-1 measure reduced 51.21% in the test group and 82.80% in the control group, with a statistically significant intergroup difference of 31.59%. For the other horizontal measurements, there was a statistically significant reduction for both HW-3 and HW-5 between the two groups. In sockets with buccal wall loss greater than 50%, the use of the bone substitute provided a 30% lower horizontal loss.
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Porzel, Alec P. "A Biomechanical Study of Critical Size Cranial Defect Reconstruction Techniques Using Two Bone Substitutes." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1208547531.
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Blom, Ashley W. "The development of a bone graft substitute for use in impaction grafting in revision total hip arthroplasty." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288558.
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Hasegawa, Shin. "In vivo evaluation of a porous hydroxyapatite/poly-DL-lactide composite for use as a bone substitute." Kyoto University, 2006. http://hdl.handle.net/2433/143845.
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SERRA, FRANCESCA GIULIA. "Bone-like inducing grafts: in vivo and micro-CT analysis." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2858349.
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Collignon, Anne-Margaux. "Utilisation de cellules souches pulpaires combinées à une matrice de collagène pour la réparation osseuse cranio-faciale Strategies developed to induce, direct, and potentiate bone healing Accelerated craniofacial bone regeneration through dense collagen gel scaffolds seeded with dental pulp stem cells Mouse Wnt1-CRE-RosaTomato dental pulp stem cells directly contribute to the calvarial bone regeneration process Early angiogenesis detected by PET imaging with 64Cu-NODAGA-RGD is predictive of bone critical defect repair." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCB113.
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La région cranio-faciale est particulièrement vulnérable aux pertes de structures. Sa localisation et sa visibilité font qu'une atteinte entraîne des troubles, aussi bien physiques (alimentation, phonation...) que psychologiques (intégrité de la personne...). Les traitements actuels (régénération osseuse guidée, autogreffe osseuse ou allogreffe) sont particulièrement invasifs et présentent un taux d'échec élevé. Tout cela affecte fortement la qualité de vie du patient. De plus, le coût direct de ces traitements est important pour les systèmes de santé et le patient. Il existe donc un réel besoin de développer des traitements innovants basés sur des approches biomimétiques d'ingénierie tissulaire pour la régénération/réparation osseuse. L'objectif de ce travail est de développer une approche d'ingénierie tissulaire pour la réparation/régénération de tissus osseux cranio-faciaux lésés. Il est basé sur l'utilisation de matrices cellularisées avec des cellules souches mésenchymateuses issues de la pulpe dentaire : les Dental Pulp Stem Cells (DPSCs). De nombreux travaux ont démontré la grande plasticité de ces cellules, qui dérivent initialement de la crête neurale, mais aussi leur rôle trophique dans la réparation de tissus lésés par leur capacité de différenciation ostéogénique et chondrocytaire. Par ailleurs, ces cellules présentent des propriétés pro-angiogéniques supérieures aux cellules mésenchymateuses de la moelle osseuse (MSCs) et l'accès à cette réserve est aisé puisqu'elles peuvent être obtenues à partir de dents extraites. Dans ce contexte, nous avons à ce jour utilisé des matrices denses de collagène contenant des cellules souches pulpaires pour régénérer un tissu osseux crânien après réalisation de défauts critiques. L'objectif est d'induire très précocement une néo-angiogenèse favorisant à court terme la survie des cellules implantées, puis de stimuler leur maintien à long terme au sein du néo-tissu implanté, pour enfin provoquer une ostéoformation. Nous avons, ainsi, pu étudier et valider différents aspects de cette thématique : .1 L'impact positif de l'utilisation de matrices denses de collagène comme support ostéoconducteur, .2 Le suivi à long terme des cellules après implantation in vivo .3 L'impact positif d'un pré-traitement à l'hypoxie sur i/ la survie des cellules après implantation in vivo ii/ la potentialisation de leur apport pour la régénération/réparation osseuse en orientant leur différenciation vers une voie ostéoblastique, .4 L'apport significatif des techniques d'imageries pour le suivi des animaux grâce à la tomographie par émission de positons (utilisation de traceurs spécifiques de la minéralisation au sein des matrices et de la néo-angiogenèse) et au microscanner à rayons X (suivi cinétique de la qualité et de la quantité de matrice osseuse régénérée), .5 La validation et la confirmation de l'ensemble de ces résultats par l'histologie. Ainsi, ces résultats nous ont permis de répondre à l'objectif de travail et de perfectionner certains aspects de la composante cellulaire. Toutefois, il reste nécessaire d'optimiser le biomatériau lui-même. Il est en effet envisageable d'améliorer les matrices de collagène compressées que nous utilisons actuellement, en y intégrant par exemple des céramiques bioactives. En perspective, potentialiser les biomatériaux des matrices et combiner les DPSCs avec un support plus adapté à leur survie et à leur croissance permettrait d'améliorer considérablement la cicatrisation osseuse. Ces dernières années, l'étude des cellules souches a progressé d'approche in vitro vers l'in vivo. Les modèles in vivo établis pour étudier ces cellules dans le domaine cranio-facial ont déjà apporté des renseignements et ce travail s'inscrit dans leur continuité en cherchant à concevoir des stratégies adaptées pour l'utilisation future des DPSCs en ingénierie tissulaireThe craniofacial area is particularly vulnerable to structural loss. Its location and visibility make a loss causes disorders, both physical (food, phonation...) than psychological (integrity of the person...). Current treatments (autografts, allografts or synthetic bone grafts) are particularly invasive and have a high failure rate. All this strongly affects the quality of life of the patient. In addition, the cost of these treatments is significant for the health systems and the patient. Therefore, there is a real need to develop innovative treatments based on biomimetic tissue approaches for bone repair. The purpose of this thesis is to develop a tissue engineering approach for the repair/regeneration of injured cranial-facial bone tissue. It is based on the use of cellularized scaffolds with mesenchymal stem cells derived from the dental pulp: Dental Pulp Stem Cells (DPSCs). Many studies have demonstrated the high plasticity of these cells, which initially derive from the neural crest, but also their trophic ability in the repair of damaged tissues by their osteogenic and chondrocyte differentiation capacity. Moreover, these cells have better's pro-angiogenic properties than mesenchymal cells of the bone marrow (MSCs) and access to this reserve is easy since they can be obtained from extracted teeth. In this context, we have used dense collagen scaffolds seeded with DPSCs to regenerate cranial bone tissue on critical defects model. The objective is to induce a very early neo-angiogenesis for improved short-term survival of implanted cells, then stimulate the long-term maintenance of cells in the implanted neo-tissue, finally to cause osteoformation. We were able to study and validate various aspects of this theme: 1- The positive impact of the use of dense collagen scaffold as osteoconductive support, 2- Long-term follow-up of the cells after implantation in vivo (thanks to the use of a cell line constitutively expressing an intracellular fluorescence protein), 3- The positive impact of a pre-treatment with hypoxia on i/ the survival of the cells after implantation in vivo ii/ their contribution to bone regeneration / repair by orienting their differentiation towards an osteoblastic pathway, 4- The significant contribution of imaging techniques for the monitoring of animals (less sacrifice and longitudinal follow-up...) thanks to positron emission tomography (use of specific tracers of the mineralization within the scaffolds and neo-angiogenesis) and X-ray microscanner (kinetic monitoring of the quality and quantity of regenerated bone matrix) 5- Validation and confirmation of all these results by histology. Thus, these different results allowed us to respond to the working hypothesis and optimize some aspects of the cellular component. However, it remains necessary to optimize the biomaterial itself. It is indeed possible to improve the compressed collagen scaffolds that we currently use, for example by incorporating bioactive ceramics such as bioglasses or hydroxyapatite. In recent years, the study of stem cells has progressed from in vitro to in vivo. The in vivo models established to study these cells in the craniofacial area have already provided valuable information and this work is a continuation of these previous studies by seeking to build on better strategies (right characterization, environment oriented...) for the future use of DPSCs for tissue engineering purposes. In view of this work, potentiating the biomaterials of the scaffolds and combining the DPSCs with a support more adapted to their survival and their growth would considerably improve bone healing, as well as bone regeneration / repair
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Ferreira, Sabrina [UNESP]. "PLA/PGA copolymer as a bone substitute in maxillary sinus augmentation: histological, histometric and immunohistochemistry study in rabbits." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/115724.
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A proposta deste estudo foi avaliar a capacidade osteocondutora da forma sólida do copolímero de PLA/PGA em um modelo experimental de enxerto em seio maxilar . Vinte coelhos machos, branco, da raça Nova Zelândia, cada um pesando cerca de 3,0 kg, foram utilizados e foram divididos em dois grupos de acordo com o material de preenchimento do seio, como segue: ósseo autógeno particulado e copolímero PLA/PGA . A área aumentada diferiu entre os grupos após 3, 7 e 15 dias (p = 0,004) . No entanto, os valores tornaram-se semelhante aos 40 dias (p = 0,458). Depois de 3 e 7 dias, a porcentagem óssea foi estatisticamente significativa entre osso autógeno e PLA / PGA copolímero (P = 0,004 e P = 0,004). Após 15 e 40 dias os valores foram semelhantes nos dois períodos (P = 0,087 e P = 0,087 ). Imunohistoquímica confirma os resultados sobre os dados histomorfométricos. Em conclusão, o copolímero de PLA/PGA parece ser adequado como material reabsorvível capaz de induzir o crescimento do osso em defeitos ósseos. Esta observação sugere que o material tem propriedades osteocondutoras também apropriado para aplicação em cirurgia maxilo-facial
The proposition of this study was evaluate the osteoconductive capability of the solid form of PLA/PGA copolymer in an experimental model of maxillary sinus grafting. Twenty male white New Zealand rabbits, each weighing about 3.0kg, were used and were divided into two groups, according to the sinus filling material, as follows: autogenous bone chips and PLA/PGA copolymers. Augmented area differ between the groups after 3, 7 and 15 days (P=0.004). However, the values became similar on day 40 (P=0.458). After 3 and 7 days the percentage of bone was statistically significant between autogenous bone and PLA/PGA copolymer (P=0.004 and P=0.004). After 15 and 40 days the values were comparable in the two periods (P=0.087 and P=0.087). Immunohistochemistry confirms the results on the histomorphometric data. In conclusion, PLA/PGA copolymer seems to be suitable as resorbable material able to induce bone growth in bone defects. This observation suggests that the material have osteoconductive properties also suitable for application in maxillofacial surgery
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Ferreira, Sabrina. "PLA/PGA copolymer as a bone substitute in maxillary sinus augmentation : histological, histometric and immunohistochemistry study in rabbits /." Araçatuba, 2014. http://hdl.handle.net/11449/115724.
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Orientador: Idelmo Rangel Garcia JúniorBanca: Wilson Roberto Poi
Banca: Ronaldo Célio Mariano
A dissertação foi escrita em inglês
Resumo: A proposta deste estudo foi avaliar a capacidade osteocondutora da forma sólida do copolímero de PLA/PGA em um modelo experimental de enxerto em seio maxilar . Vinte coelhos machos, branco, da raça Nova Zelândia, cada um pesando cerca de 3,0 kg, foram utilizados e foram divididos em dois grupos de acordo com o material de preenchimento do seio, como segue: ósseo autógeno particulado e copolímero PLA/PGA . A área aumentada diferiu entre os grupos após 3, 7 e 15 dias (p = 0,004) . No entanto, os valores tornaram-se semelhante aos 40 dias (p = 0,458). Depois de 3 e 7 dias, a porcentagem óssea foi estatisticamente significativa entre osso autógeno e PLA / PGA copolímero (P = 0,004 e P = 0,004). Após 15 e 40 dias os valores foram semelhantes nos dois períodos (P = 0,087 e P = 0,087 ). Imunohistoquímica confirma os resultados sobre os dados histomorfométricos. Em conclusão, o copolímero de PLA/PGA parece ser adequado como material reabsorvível capaz de induzir o crescimento do osso em defeitos ósseos. Esta observação sugere que o material tem propriedades osteocondutoras também apropriado para aplicação em cirurgia maxilo-facial
Abstract: The proposition of this study was evaluate the osteoconductive capability of the solid form of PLA/PGA copolymer in an experimental model of maxillary sinus grafting. Twenty male white New Zealand rabbits, each weighing about 3.0kg, were used and were divided into two groups, according to the sinus filling material, as follows: autogenous bone chips and PLA/PGA copolymers. Augmented area differ between the groups after 3, 7 and 15 days (P=0.004). However, the values became similar on day 40 (P=0.458). After 3 and 7 days the percentage of bone was statistically significant between autogenous bone and PLA/PGA copolymer (P=0.004 and P=0.004). After 15 and 40 days the values were comparable in the two periods (P=0.087 and P=0.087). Immunohistochemistry confirms the results on the histomorphometric data. In conclusion, PLA/PGA copolymer seems to be suitable as resorbable material able to induce bone growth in bone defects. This observation suggests that the material have osteoconductive properties also suitable for application in maxillofacial surgery
Mestre
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Ioanovici, Teodora. "Contribuții la sinteza de hidroxiapatită dopată cu magneziu și cercetări asupra proprietăților mecanice în vederea utilizării ei în implanturi osoase." Thesis, Artois, 2012. http://www.theses.fr/2012ARTO0208/document.
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Pour le comblement d'une perte de tissu, la greffe reste une méthode usitée en chirurgie osseuse mais une lacune importante conduit à l'emploi de matériaux artificiels. Alternative aux implants métalliques, les substituts osseux biocéramiques ont une efficacité insuffisante dans de nombreuses indications : problème d'intégration d'un volume important, résistance inadéquate à long terme, faible bioréactivité. Doper ces biocéramiques est une voie intéressante mais nombre de dopants ont abouti à des effets cytotoxiques voire à la dégradation des propriétés mécaniques. Le magnésium a été étudié comme dopant de l'hydroxyapatite pour des faibles teneurs, apportant des améliorations sans affecter la biocompatibilité. Cependant, les fortes teneurs et l'optimisation de la synthèse d'une biocéramique dopée ont été peu étudiées. Nous avons étudié et optimisé la synthèse d’hydroxyapatite par la méthode de précipitation aqueuse pour un dopage au magnésium de 1, 2, 5 et 10 % en masse. Caractérisations physicochimiques (DRX, MEB, densité), biologiques (cytotoxicité) et mécaniques (microdureté, élasticité) ont été menées (poudres ou pastilles frittées ou non). Nous avons montré l'apparition de TCP à partir de 2 % Mg, la densité des échantillons diminuant quand la teneur croît. Le dopage accroît la microdureté et le module d’Young. Aucune cytotoxicité n'a été révélée mais une importante baisse d’activité cellulaire a été remarquée pour 10 % de magnésium. Une légère augmentation a été observée pour 1 %. L'aptitude à la mise en forme a été appréciée via le coulage d'une réplique d'un implant intervertébral. Le dopage d'HA à 1 % Mg s'avère être à tout point de vue le compromis optimalFor the filling of a loss of tissue, the graft is a current process in bone surgery, but a significant deficiency leads to the use of artificial materials. Alternative to metallic implants, bone substitutes bioceramics have insufficient efficacy in many indications: problem of integrating a large volume, inadequate long-term resistance, low bioreactivity. Doping these bioceramics is an interesting way but many of dopants have conducted to cytotoxic effects or to the degradation of mechanical properties. Magnesium has been studied as a dopant of hydroxyapatite for low contents, improving thebioceramic without affecting its biocompatibility. However, high contents and the optimization of the synthesis of such a doped bioceramic have been little studied. We investigated and optimized the synthesis of hydroxyapatite by the aqueousprecipitation process for magnesium doping of 1, 2, 5 and 10 wt%. Physico-chemical (XRD, SEM, density), biological (cytotoxicity) and mechanical (microhardness, elasticity) characterizations were conducted (on powders or pellets sintered or not). We have shown the occurrence of TCP from 2% Mg, the density of samples decreasing when the content grows. The doping increases the microhardness and the Young’s modulus. No cytotoxicity was revealed but a significant decrease in cellular activity was noted for 10% magnesium. A slight increase was observed for 1%. The ability to form an implant was assessed via the slip casting of a replica of an intervertebral implant. Doping HA to 1% Mg was found to be at any point of view the optimum composition
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Kluppel, Leandro Eduardo. "Influencia dos diferentes tamanhos de particulas da matriz ossea bovina anorganica no processo de reparo osseo : Analise histologica e radiografica de defeitos criados cirurgicamente em calvaria de coelhos." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288695.
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Orientador: Renato MazzonettoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O objetivo deste estudo foi analisar histológica e radiograficamente a influência do tamanho das partículas da matriz óssea bovina anorgânica (MOBA) sobre o processo de reparação óssea. Na calvária de 18 coelhos adultos da raça Nova Zelândia foram preparadas quatro cavidades com diâmetro de 8 milímetros, sendo duas do lado direito da sutura sagital e duas do lado esquerdo. Os defeitos foram preenchidos com osso autógeno triturado (grupo controle); MOBA de granulação grossa; MOBA de granulação média ou MOBA de granulação fina. Os animais foram sacrificados nos períodos pós-operatórios de 15, 30 e 60 dias. Antes do início do processamento histológico, as peças foram radiografadas sequencialmente. Para análise destas imagens utilizou-se como padrão de comparação o osso do crânio que não estava envolvido nas áreas de ostectomia. Desta forma, observou-se que o osso autógeno apresentava-se discretamente radiopaco inicialmente, tendendo a apresentar uma radiopacidade bastante semelhante ao tecido adjacente no período final. A MOBA de granulação grossa e média mantiveram o mesmo padrão radiográfico, sendo que aos 60 dias, o aparecimento de uma porção radiolúcida em sua porção central pode ser observada. Já a MOBA de granulação fina apresentava discreta radiolucidez no período inicial, a qual tornou-se mais intensa nos períodos sucessivos. A análise histológica demonstrou a formação de maior quantidade de osso e menos reação inflamatória no grupo controle (osso autógeno). Para o biomaterial, em todas as granulações pôde-se observar a presença de infiltrado inflamatório considerável nos períodos de 15 e 30 dias. Nos defeitos preenchidos pela MOBA de granulações grossa e média o processo de reparação transcorreu de maneira semelhante, sendo que no período final uma grande quantidade de partículas e tecido conjuntivo fibroso ainda estavam presentes na cavidade. Contrariamente, a MOBA de granulação fina proporcionou a formação de maior quantidade de tecido osteóide e as partículas foram reabsorvidas quase que em sua totalidade transcorridos 60 dias de sua implantação. Com base nos resultados obtidos, conclui-se que: (1) o enxerto ósseo autógeno isoladamente proporcionou o melhor resultado em termos de reparação dos defeitos ósseos; (2) a MOBA é um material biocompatível; (3) a MOBA de granulação grossa e média não são reabsorvidas em sua totalidade no período observado; (4) a MOBA de granulação fina foi reabsorvida de forma mais intensa e proporcionou uma maior formação de tecido osteóide quando comparada às outras granulações
Abstract: The aim of this present study was to analyze, clinical and histologically, the influence of anorganic bovine bone matrix (ABBM) particle size on bone repair. Four calvarial defects of 8 millimeters each were prepared in 18 adult New Zealand rabbits, two in the right side, and two in the left side. The defects were filled with either particulate autogenous bone (control group); ABBM of large size granules; ABBM of medium size granules; or ABBM of small size granules. The animals were sacrificed at 15, 30, and 60 days after surgery. The samples were radiographic examined before being submitted to histological processing. The analysis of these radiographic images was performed by comparing them with images of the cranial bone not involved with the areas of osteotomy. Thus, it was observed that autogenous bone showed a slight radiopacity at the beginning which was increased at the final period, being very similar to the adjacent bone tissue in terms of radiopacity. The large and medium size ABBM particles maintained the same radiographic behavior, showing a radiolucid area in the central portion of the defect at 60 days. On the other hand, the ABBM of small size granules showed a slight radiolucity at the initial period, which was increased at the subsequent periods. The histological analysis showed a more intense bone formation within the control group (autogenous bone). With regards to the biomaterial, it was observed that all three particle sizes resulted in inflammatory infiltration at 15 and 30 days. The bone repair at the defects filled with ABBM of medium or large size granules was similar to each other, with the presence of a large amount of remaining particles and fibrous connective tissue in the defect at the final period. In contrast, ABBM of small size granules lead to a greater amount of osteoid tissue, and the particles were almost totally reabsorbed within 60 days of implantation. Based on these results, it was concluded that: (1) autogenous bone graft lead to the best result in terms of bone defect repair; (2) ABBM is a biocompatible material; (3) ABBM of large and medium size granules are not totally reabsorbed at the observed period; (4) ABBM of small size granules was more intensively reabsorbed, and lead to a greater osteoid tissue formation when compared to the medium and large ABBM granules
Mestrado
Cirurgia e Traumatologia Buco-Maxilo-Faciais
Mestre em Clínica Odontológica
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Yaszemski, Michael Jerome. "The design, synthesis, characterization, and mechanical testing of a novel degradable polymeric biomaterial for use as a bone substitute." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/38739.
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Rice, Hilary Callahan. "Evaluation of a Novel Bone Substitute Injection Technique for Potential Treatment of Impact Injury to the Equine Palmar Metacarpal Condyle." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1551687367927699.
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Zhang, Ganggang. "Tests des composés de nacre sur l'activité des ostéoblastes et leur identification." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0051/document.
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Avec de nombreuses qualités exceptionnelles (biocompatible et ostéogénique), la nacre représente un biomatériau naturel comme substitut osseux. Mais les composés ostéogéniques dans la nacre ne sont pas encore connus. Nos travaux visent à l’identification des composés ostéogéniques de la nacre. L’ESM (éthanol soluble matrix) est un extrait de la nacre qui est démontré ostéogénique. A partir d’ESM, nous avons essayé plusieurs approches pour cibler et identifier ces composés. Grâce au couplage des cellules MC3T3-E1 et d’ostéoblastes humains arthrosiques, nous avons démontré que la partie cationique d’ESM est ostéogénique, sans interaction avec la partie anionique. Le calcium joue un rôle dans l’activité ostéogénique d’ESM. Ensuite, nous avons créé une lignée cellulaire exprimant de manière stable un plasmide contenant un gène rapporteur ostéogénique (ATDC5 pMetLuc2 ColX promoteur). Grâce à cette lignée, nous avons découvert que les lipides et les sucres présents dans l’ESM ont un effet ostéogénique. Les peptides précipités par TCA sont aussi démontrés ostéogéniques, et ont conduit à leur identification partielle par LC-MS. Ces résultats nous permettent d’avancer plus loin et plus rapidement vers l’identification des composés ostéogéniques de la nacre et vers les applications de la nacre en orthopédie cliniqueWith many exceptional qualities (biocompatible and osteogenic), nacre represents a natural biomaterial as a bone substitute. However, the osteogenic compounds in nacre are not yet known. Our work aims at the identification of the osteogenic compounds in nacre. The ESM (soluble ethanol matrix) is an extract of nacre that is shown to be osteogenic. From the ESM, we have tried several approaches to target and identify these compounds. Thanks to the coupling of MC3T3-E1 cells and the human osteoarthritis osteoblasts, we demonstrated that the cationic part of the ESM is osteogenic, without interaction with the anionic part. Calcium plays a role in the osteogenic activity of the ESM. Then, we created a cell line stably expressing a plasmid containing an osteogenic reporter gene (ATDC5 pMetLuc2 ColX promoter). Thanks to this cell line, we found out that the lipids and sugars in the ESM have an osteogenic effect. The peptides precipitated by TCA are also demonstrated to be osteogenic, which have led to their partial identification by LC-MS. These results allow us to move farther and faster towards the identification of osteogenic compounds in nacre and the applications of nacre in clinical orthopaedics
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Mirdamadian, Pegah, and Nargi Raha Salahshour. "Grafting materials for alveolar cleft reconstruction -a systematic review." Thesis, Malmö universitet, Odontologiska fakulteten (OD), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-42795.
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Aim: The aim of this literature study was to systematically review the scientific evidence on the most effective donor sites and/or bone substitute material for secondary alveolar cleft grafting in alveolar cleft patients. Material and method: In order to acquire a systematic and transparent reporting this literature review was conducted according to the PRISMA statement. The literature search was performed in the following four databases; PubMed, CENTRAL, Web of Science and Scopus.The quality of the included studies was assessed using the revised Cochrane Risk of Bias 2 tool (RoB 2 tool). Result: The search identified 4754 studies. Five RCT studies was included in this systematic review and assessed different donor site or bone substitute materials. Two studies showed low risk of bias and three moderate risk of bias. Only one study showed a statistically significant difference when comparing iliac bone to substitute material however all studies presented substitute materials with satisfactory results. Conclusion: According to the data from this systematic review no clear conclusion can be drawn regarding what the most effective bone donor site and/or tissue engineered bone substitute material to use in secondary bone grafts. Based on the available evidence iliac bone could still be regarded as a benchmark, but more research and RCT’s of high quality are required, especially for artificial bone substitute materials.Syfte: Syftet med denna litteraturstudie var att systematiskt granska den vetenskapliga evidensen gällande det mest effektiva bentagningsstället och/eller bensubstitutmaterialet vid sekundär bentransplantation hos patienter med käkspalt. Material och metod: För att uppnå en systematisk och transparent rapportering av denna litteraturstudie följdes PRISMA statement. Litteratursökningen gjordes i följande fyra databaser; PubMed, CENTRAL, Web of Science och Scopus. Kvaliteten av inkluderade studier granskades med hjälp av Cochrane Risk of Bias 2 tool (Rob 2 tool). Resultat: Sökningen identifierade 4754 studier. Fem RCT studier inkluderades i denna systematiska översikt vilka värderade olika bentagningsställen eller bensubstitut. Två studier bedömdes ha låg risk för bias och tre artiklar måttlig risk för bias. Endast en studie visade på en statistiskt signifikant skillnad vid jämförelse av höftben med bensubstitut däremot presenterade samtliga studier substitutmaterial med tillfredsställande resultat. Konklusion: Denna systematiska översikt visade att ingen klar slutsats kan dras gällande vilken det mest effektiva bentagningsstället eller bensubstitutsmaterialet är för sekundär bentransplantation hos patienter med käkspalt. Baserat på tillgänglig evidens kan transplantat från höftbenet fortfarande anses vara bäst lämpat men mer forskning samt RCT studier av hög kvalité erfordras, särskilt för artificiella bensubstitutmaterial.
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Ensir, Hana Ayad [Verfasser], and Christine [Akademischer Betreuer] Knabe-Ducheyne. "Effect of a highly bioactive calcium alkali orthophosphate-based bone grafting material as compared to a tricalcium phosphate bone substitute on osteogenesis after sinus floor augmentation in patients / Hana Ayad Ensir ; Betreuer: Christine Knabe-Ducheyne." Marburg : Philipps-Universität Marburg, 2021. http://d-nb.info/1239239831/34.
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Harden, Fiona J. "Digging into bone : investigative studies into silicate-substituted hydroxyapatite, collagen molecules and bone properties." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=211423.
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Investigations into silicate-substituted hydroxyapatite (Si-HA) were performed. The aqueous precipitation method produced phase pure Si-HA with modi cations to the method causing impurities in the material. A novel study using Raman spectroscopy followed the behaviour of the silicate ions and provided a new interpretation regarding silicate substitution. The silicate ions created interactions with hydroxyl ions, initially, which reduced upon sintering of the material. As the silicate ions do not behave inde- pendently in the HA structure initially, suggests that these interactions may contribute to the bioactivity of Si-HA. Also industrial aspects of Si-HA were investigated regarding the silicate reagent (TEOS). A small di erence of 1% in the percentage concentration of TEOS was not negligible and caused a decrease in the amount of silicate substituted into HA. Di erent brands and grades of TEOS did produce Si-HA with similar structural properties. Therefore, a variety of brands and grades of TEOS can be used and thus the most cost e ective choice can be made. The rst analytical investigations into the molecular arrangement of fully mineralised osteoarthritic (OA) and osteoporotic (OP) bone were performed through small angle neutron scattering (SANS) studies. This study provided a description for the molecular arrangement of collagen molecules, along the lateral plane, regarding the molecular di- ameter and the packing of these molecules into the bril by the development of a model based on SANS theory. The collagen molecules behave like a 2-dimensional liquid-like system. Through the development of the model, the rst written solution for the struc- ture factor for a system of hard-disks was stated. This study provided an understanding into how collagen molecules are arranged in OA and OP bone. Also, compositional studies iterated possible di erences between the organic content of OA and OP bone. Thus the organic content of bone may play a role in the bone disorders.
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Guimarães, Maria Rosa Felix de Sousa Gomide. "Reparo ósseo de defeitos cirúrgicos críticos preenchidos ou não com ß - fosfato tricálcio (RTR® - Septodont) : estudo histológico e histométrico em tíbias de ratos /." Araçatuba, 2016. http://hdl.handle.net/11449/144731.
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Orientador: Eloi Dezan JuniorBanca: Gustavo Sivieri de Araújo
Banca: Luciano Tavares Angelo Cintra
Banca: Christine Men Martins
Banca: Renata Oliveira Samuel
Resumo: Objetivos: Analisar histologicamente e histometri camente o efeito do RTR ® em defeitos óss eos cirúrgicos críticos em tíbias de ratos no processo de reparo ósseo. Materiais e Métodos: Defeitos ósseos crítico s foram criados nas tíbias de 32 ratos Wistar divididos em dois grupos: Grupo Coágulo e Grupo RTR ® . Após o período experimental de 30 e 90 dias, o s animais fora m sacrificados e as peças incluída s em parafina, cortadas e coradas com hematoxilina e eo sina . Dois parâmetros foram analisados: a área óssea total neoformada (AON) e a área óssea da cortical neoformada (ACN). A análise estatística foi realizada nos dois períodos de observação pela análise de variância (ANOVA) e pelo Te ste de Tukey. Resultados: Todos os grupos demonstraram reparo ósseo superior quando comparados ao Grupo C oágulo 30 dias nos dois parâmetros analisados . O G rupo RTR ®, em 30 e 90 dias, apresentou reparo da cortical óssea e formaçõ es de tecido ósseo na reg ião central do defeito maior do que no Grupo Coágulo de 90 dias, que apresentou reparo parcial da cortical óssea e poucas formações de tecido ósseo na região do defeito (p<0,05). Conclusões: O RTR ® favoreceu a neoformação óssea no modelo experimental adotado podendo ser indicado em casos de cavidades ósseas de tamanho crítico.
Abstract: Objectives: To analyze histologically and histometrically the effect of RTR ® on critical surgical bone defects in rat tibiae in the bone repair process. Materials and Methods: Critical bone defects were created in the tibia of 32 Wistar rats divided into two groups: Clot Group and RTR ® Group. After the experimental period of 30 and 90 days, the animals were sacrificed and the paraffin embedded pieces were cut and stained with he matoxylin and eosin. Two parameters were analyzed: total neoformed bone area (AON) and bone area of neoformed cortical (ACN). Statistical analysis was performed in the two observation periods by analysis of variance (ANOVA) and Tukey's test. Results: All groups demonstrated superior bone repair when compared to the Clot Group 30 days in the two analyzed parameters. The RTR ® Group, in 30 and 90 days, presented repair of the cortical bone and bone tissue formations in the central region of the defect greate r than in the 90 - day Clot Group, which presented partial repair of the cortical bone and few bone tissue formations in the r egion of the defect (p <0.05). Conclusions: The RTR ® favored the bone neoformation in the adopted experimental model and can be indi cated in cases of bone of critical size.
Doutor
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Pereira, Rodrigo dos Santos [UNESP]. "Estudo comparativo do vidro bioativo e osso autógeno em aumento do assoalho de seios maxilares de humanos." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143871.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A deficiência óssea vertical do seio maxilar impossibilita a instalação de implantes dentais necessários para a reabilitação protética contudo, técnicas cirúrgicas para a elevação da membrana sinusal e o uso dos biomateriais para enxertia óssea permitiram alterar esta condição. O ósseo autógeno é considerado o mais previsível e o padrão ouro para tal finalidade porém, biomateriais como o vidro bioativo, amplamente utilizado na odontologia, permitem substituí-lo. O objetivo deste estudo foi avaliar formação óssea, o comportamento celular e a taxa de reabsorção do vidro bioativo em 2 proporções: puro (grupo 1); adicionado ao osso autógeno 1:1 (grupo 2), comparando com o osso autógeno (grupo 3) em seios maxilares de humanos. Com 15 dias de operados os pacientes realizaram um tomografia computadorizada (TC) cone beam para determinar o volume inicial do enxerto (T1). Após 6 meses uma nova TC foi realizada determinando o volume ósseo final (T2) e também, a coleta das biópsias com a instalação simultânea de implantes dentais. As amostras foram divididas em 3 áreas: leito, intermediária e apical onde foram avaliadas a histomorfometria e imunomarcações para Runx2, VEGF, osteocalcina e TRAP. No grupo 1 os resultados foram de 42.6%, 44.5% e 48% de formação óssea no leito, intermediária e apical respectivamente. No grupo 2 as taxas encontradas foram de 36.6% no leito, 33.2% na intermediária e 45.8% na apical. No grupo 3 foi de 34.4% para o leito, 35.0 na intermediária e 42.0% na apical. (p>0.05) Os 3 grupos apresentaram-se com comportamento semelhante nas imunomarcações realizadas mostrando estar maturado e calcificado o suficiente para receber implantes dentais. As taxas de reabsorção também mostraram-se semelhantes com 44.2% para o grupo 1, 37.9% para o grupo 2 e 45.7% no grupo 3. (p>0.05) Assim, podemos concluir que o vidro bioativo possui resultados equiparados ao osso autógeno.
Vertical bone deficit due maxillary sinus pneumatization forbid the dental implants placement required for prosthetic rehabilitation however, surgical techniques to elevate maxillary sinus membrane and studies about biomaterials, allows repair these situation. Autogenous bone graft is considered the most predictable and the gold standard for this nevertheless, biomaterials as bioactive glass, has been widely used in dental surgery and allows substitute it. The aim of this study was evaluate the bone formation, the cellular behavior and the resorption rates of bioactive glass in 2 proportions: pure (group 1); add to autogenous bone graft (group 3), comparing then with autogenous bone graft in human maxillary sinus. Post-operative cone beam computed tomography (CT) was used to measure the initial graft volume after 15 days (T1). Six months later, another CT was performed to evaluate the final graft volume (T2) and determine the graft resorption rate and the harvest of biopsies with dental implants placement simultaneously. The samples were divided in 3 areas: bed, intermediately and apical which were evaluated to histomorphometric and immunostaining to Runx2, VEGF, osteocalcin and TRAP. In group 1 the bone formation were 42.6%, 44.5 and 48.0% for bed, intermediately and apical respectively. In group 2 the rates were 36.6% in bed, 33.2% in intermediately and 45.8% in apical. In group 3 were 34.4% in bed, 35.0% in intermediately and 42.0% in apical. (p>0.05) the 3 groups had the same behavior for the 4 proteins showing be matured and calcified to receive dental implants. The resorption rates were similar for the 3 groups with 44.2% % for group 1, 37.9% for group 2 and 45.7% for group 3. (p>0.05) In conclusion, the bioactive glass is a good substitute to autogenous bone graft in both proportions evaluated.
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Ribeiro, Luciana Liarte Gasparini [UNESP]. "Avaliação histológica do comportamento da matriz dérmica acelular e do vidro bioativo no processo de reparo de cavidade cirúrgica em tíbia de rato." Universidade Estadual Paulista (UNESP), 2003. http://hdl.handle.net/11449/96170.
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ribeiro_llg_me_araca.pdf: 2853983 bytes, checksum: a31d486596397bffae06e459957416c4 (MD5)Nos últimos vinte anos, o estudo da regeneração das estruturas periodontais influenciou o desenvolvimento das terapias ósseas regenerativas. A regeneração óssea guiada cria um ambiente adequado para que ocorra a regeneração de tecido ósseo através do selamento da área do defeito com uma membrana. Quando os defeitos assumem grandes proporções, se faz necessário o uso do enxerto ósseo, podendo ser feito com o autógeno, alógeno, xenógeno ou materiais aloplásticos. O objetivo deste trabalho foi avaliar, histologicamente, em cavidades cirúrgicas realizadas em tíbias de ratos, o papel da matriz dérmica acelular como membrana na cicatrização óssea, o papel das partículas de vidro bioativo na cicatrização óssea, e o papel das partículas de vidro bioativo protegidas pela membrana de matriz dérmica acelular na cicatrização óssea. Os resultados revelaram que a matriz dérmica acelular apresentou biocompatibilidade e que foi capaz de isolar a cavidade cirúrgica, comprovando sua capacidade de ser empregada como membrana no processo de cicatrização sem interferir, significativamente, com a formação óssea; que o vidro bioativo mostrou-se biocompatível, sendo que as partículas estavam interpostas ao tecido ósseo neoformado, acarretando menor grau de formação óssea, e que o emprego da matriz dérmica acelular como proteção do vidro bioativo não assegurou um resultado superior ao do grupo em que o vidro bioativo foi utilizado sem a proteção de uma membrana.
In the last twenty years, the regeneration of the periodontal structures has influenced the development of the new regenerative bone therapies. The guided bone regeneration promotes favorable conditions for the healing of the bone tissue through sealing the problem area with a membrane. When the problem area takes large proportions, a bone graft is needed; it can be autogenic, alogenic, xenogenic or alloplastic materials. The aim of this paper is to evaluate, histologycally, in the surgical cavities performed in tibial of rats, the role of the particles of bioactive glass protected by the membrane of the acellular dermal matrix in the bone healing. The results presented that the acellular dermal matrix showed biological compability and that it was able to isolate the surgical cavity proofing its ability of being used as membrane in the healing process without significantly interfering with the bone regeneration; that the bioactive glass is biological compatible, and the particles were interposed in the neoformed bone tissue leading to a decreased in bone formation, and that the use of acellular dermal matrix as a protection of bioactive glass did not show better results when compared to the group in which the bioactive glass was used without the membrane protection.
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Tinajero, Aroni Mauricio Andres. "Avaliação in vivo do efeitos do osso bovino desproteinizado revestido com estrôncio sobre o reparo ósseo /." Araraquara, 2016. http://hdl.handle.net/11449/138868.
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Orientador: Rosemary Adriana Chiérici MarcantonioBanca: Ricardo Andres Landázuri Del Barrio
Banca: Roberto Henrique Barbeiro
Resumo: Objetivo: Avaliar o efeito do revestimento com estrôncio em duas concentrações sobre o potencial de reparo ósseo do osso bovino desproteinizado (DBB) em defeitos críticos de calvárias (DCC) de ratos. Material e métodos: Foram utilizadas 42 ratas que foram randomicamente divididas em 3 grupos(n=14) de acordo com o tipo de biomaterial utilizado para preencher os DCC: Grupo DBB-Osso bovino desproteinizado; Grupo DBB/Sr 1(140µM por g de DBB); Grupo DBB/Sr 2(700µM por g de DBB). Foram confeccionados dois defeitos ósseos circulares (Ø5mm) nos ossos parietais dos animais, sendo que um defeito foi preenchido com biomaterial e o outro foi mantido apenas com coágulo (controle negativo). Os animais foram submetidos a eutanásia após 15 e 60 dias do procedimento cirúrgico (n=7 animais/período). Os animais foram avaliados com relação ao volume do preenchimento do DCC com tecido reparado e o tamanho remanescente do DCC por meio de análise microtomográfica. A composição do tecido reparado e as características da cicatrização foram determinadas por meio de análise histométrica/descrição histológica, enquanto que a expressão das proteínas TGFβ1 e Osteocalcina (OCN) foi realizada por análise imuno-histoquímica. Resultados: O DBB/Sr2 induziu o maior fechamento e preenchimento do DCC que os outros grupos. O DBB/Sr1 e DBB/Sr2 apresentaram maior componente de tecido ósseo dentro do tecido reparado do que os DCC preenchidos com DBB no período de 60 dias. Adicionalmente, também foi verificado que o D... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Objective: Evaluate the healing potential of deproteinized bovine bone (DBB) coated with strontium at two concentrations in critical defects of calvarial rats (DCC). Methods: We used 42 rats that were divided randomly into 3 groups (n = 14) according to the type of biomaterial used to fill the DCC: Group DBB - Deproteinized bovine Bone; Group DBB / Sr 1 (140μM per g DBB); Group DBB / Sr 2 (700μM per g DBB). Two circular bone defects (Ø5mm) were prepared in the parietal bones of the animals and one defect was filled with biomaterial and the other was maintained empty (negative control). The animals were sacrificed after 15 and 60 days after surgery (n = 7 animals / period). The animals were evaluated according the filing volume of the DCC with the repair tissue and the residual size of the DCC by microtomográfica analysis. The composition of the repaired tissue and healing characteristics were determined by Histometrical / histological description analysis, while the expression of TGFβ1 and osteocalcin (OCN) were determined by immunohistochemical analysis. Results: The DBB / Sr2 induced the highest closing and filling of the DCC than the other groups. The DBB / Sr1 and DBB / Sr2 showed greater bone tissue section within the repaired tissue than DCC filled with DBB within 60 days. Additionally, it was also found that the DBB / Sr1 and DBB / Sr2 induced a higher expression of OCN. Conclusion: The addition of Sr (700 mM) improved the quality of bone healing induced by DBB.
Mestre
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Tinajero, Aroni Mauricio Andres. "Avaliação pré-clínica dos efeitos do osso bovino desproteinizado revestido com estrôncio sobre o reparo ósseo /." Araraquara, 2019. http://hdl.handle.net/11449/183658.
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Orientador: Rosemary Adriana Chiérici MarcantonioResumo: O objetivo deste estudo foi avaliar o efeito do uso de diferentes substitutos sobre o reparo ósseo de defeitos críticos de calvárias de ratos com ou sem osteoporose. Para tanto, foram divididos em três estudos. O estudo 1 avaliou o efeito de diferentes biomateriais sobre o reparo de defeitos críticos de calota (DCC) de 40 ratos saudáveis que foram aleatoriamente divididos em 5 grupos com 8 animais, de acordo com o tipo de biomaterial utilizado para preencher os DCC: Grupo COA (coágulo); Grupo AUT (osso autógeno); Grupo OBD (osso bovino desproteinizado); Grupo HA/ TCP (cerâmica bifásica composta de hidroxiapatita e β-fosfato tricálcio); Grupo TCP (β-fosfato tricálcio). Foram executadas análise microtomográfica para avaliação do comprimento linear remanescente (DLL) do DCC e o volume dos tecidos mineralizados (MT) dentro do defeito nos períodos de 3, 7, 15 e 30 dias após cirurgia. Adicionalmente, foi executado análise histométrica para avaliar a composição do tecido ósseo reparado (% Osso e % Biomaterial) no período de 30 dias. O grupo COA apresentou o menor DLL e MT dentro do DCC e maior % osso do que os outros grupos. O grupo OBD apresentou maior volume de tecidos mineralizados e maior % biomaterial do que o grupo os grupos AUT e TCP. Os grupos OBD e AUT apresentaram maior % osso que o grupo TCP. O estudo 2 avaliou o efeito do enxerto com OBD carregado de estrôncio (Sr) na cicatrização óssea em DCC em 42 ratos saudáveis. Foram feitos 2 defeitos/rato, e um destes aleatoriament... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Valentini, Neto Rodolpho [UNESP]. "Resposta tecidual ao implante ósseo xenógeno inorgânico variando-se o método de esterilização: avaliação histomorfológica e histomorfométrica." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/101065.
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valentinineto_r_dr_araca.pdf: 348074 bytes, checksum: fe35ce64122835a7383e6940b91d45a5 (MD5)Proposição: Este estudo avaliou a resposta tecidual ao implante xenógeno inorgânico de osso bovino, por meio de análise histomorfológica e histomorfométrica, variando-se o método de esterilização. Materiais e Método: Discos de 8 mm costela bovina foram obtidos por processamento específico para remoção de parte orgânica e foram esterilizados por meio de autoclavagem ou radiação gama. Em seguida, 20 coelhos brancos (Nova Zelândia) foram cirurgiados para instalação dos discos na face lateral dos gônios mandibulares, bilateralmente, através de parafuso de fixação de enxertos, originando dois grandes grupos: Grupo EA - implante autoclavado; Grupo EI – implante gama-irradiado. As lâminas foram obtidas nos períodos de 15 e 45 dias pós-operatórios e as imagens teciduais foram analisadas qualitativa e quantitativamente. Resultados: O teste de Kruskal-Wallis foi aplicado e não identificou diferença significativa entre as medidas lineares das interfaces osso/implante (BIC) dos grupos dentro dos mesmos períodos (15 dias: p=0,100; 45 dias: p=0,940). Conclusão: De acordo com a metodologia aplicada, foi possível concluir que o estabelecimento da integração osso/implante cursou com atraso quando o implante foi esterilizado por radiação, porém, com a evolução da reparação, o método de esterilização não ocasionou alterações significativas no período final
Proposition: This study evaluated the tissue response to the implant inorganic xenogenic bovine bone through the histomorphological analysis, varying the method of sterilization. Materials and Methods: Discs of 8 mm bovine rib were obtained by specific processing to remove organics phase and were sterilized by autoclaving or gamma radiation. Then, 20 white rabbits (New Zealand) were operated for discs installation on gonion external side of mandibular, bilaterally, through screw grafts, yielding two large groups: EA - implant autoclaved; EI Group - gamma-irradiated implant. Slides were obtained at 15 and 45 days post-operative tissue and the images were analyzed qualitatively and quantitatively. Results: The Kruskal-Wallis test was used and no difference was found between linear interfaces of the bone / implant (BIC) groups within the same period (15 days: p = 0.100; 45 days: p = 0.940). Conclusion: According to the methodology, it was concluded that the establishment of integration bone / implant occurred later when the implant was sterilized by radiation in initial period, but with the evolution of repair, the method of sterilization did not cause significative changes in the final period
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Colete, Juliana Zorzi [UNESP]. "Uso do copolímero de PLA/PGA no processo de reparo de defeitos ósseos em tíbia de coelhos: análise histomorfométrica." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/115725.
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000796532.pdf: 4641017 bytes, checksum: d8cd53f3dd65a91b0dd3f3efd5ff963b (MD5)Objetivo: Analisar a influência do copolímero de ácido polilático e poliglicólico (PLA/PGA) associado ou não ao osso autógeno no processo de reparo ósseo, em defeitos críticos criados em tíbia de coelhos, por meio da análise histomorfométrica. Material e Método: Doze coelhos receberam 2 ostectomias em cada tíbia por meio de trefina de 6.1 mm de diâmetro. Os defeitos ósseos críticos foram preenchidos de acordo com os seguintes grupos: coágulo sanguíneo (GC), osso autógeno (GA), PLA/PGA (GP) e PLA/PGA associado ao osso autógeno (GPA). Seis animais por período foram submetidos à eutanásia aos 7 e 30 dias pós-operatórios, para a análise histomorfométrica. Resultados: Aos 7 dias, na comparação entre GC(48,33%), GA(25,67%), GP(4,17%) e GPA(21,5%), notou-se diferença estatisticamente significante (Kruskal-Wallis, p=0,0163), evidenciada na comparação entre os GC e GP (Teste de Dunn, p<0,05). Aos 30 dias, a comparação entre GC(56,17%), GA(61,50%), GP(67,33%) e GPA(50,50%), não mostrou diferença estatisticamente significante (Kruskal-Wallis, p=0,2026). Conclusão: Foi possível concluir, neste modelo experimental, que o copolímero PLA/PGA é um biomaterial com propriedades osteocondutoras e pode ser utilizado de maneira isolada, sem a presença de osso autógeno associado.
Objective: To analyze the influence of polylactic/polyglycolic acid copolymer (PLA/PGA) associated or not with autogenous bone in the bone repair process in critical size defects of rabbit tibia through histomorphometric analysis. Methods: Twelve rabbits received 2 osteotomies in each tibia through trephine (6.1 mm diameter). The critical bone defects were filled according to the following groups: blood clot (GC), autogenous bone (GA), PLA / PGA (GP) and PLA / PGA associated with autogenous bone (GP). Six animals were euthanized at 7 and 30 days postoperatively. Results: At 7 days, through of groups comparison GC (48.33 %), GA (25.67 %), GP (4.17 %) and GPA (21.5 %) was observed statistically significant difference (Kruskal-Wallis, p= 0.0163), when compared GC and GP groups (Dunn, p < 0.05). At 30 days, the comparison between GC (56.17 %), GA (61.50 %), GP (67.33 %) and GPA (50.50 %) showed no statistically significant difference (Kruskal-Wallis, p = 0.2026). Conclusion: PLA / PGA copolymer is a biomaterial with osteoconductive properties and can be used isolated without autogenous bone supplementation.