Orientador: Wilkens Aurélio Buarque e Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T01:35:28Z (GMT). No. of bitstreams: 1 Ribeiro_LiviaForster_M.pdf: 2135600 bytes, checksum: 328020004d2dfccf85672ad44205aa07 (MD5) Previous issue date: 2012 / Resumo: Este estudo in vitro teve como objetivo, avaliar as deformações de implantes e componentes protéticos de uma prótese parcial fixa implantossuportada, submetida às cargas axiais por meio da extensometria elétrica. Foi confeccionado um modelo experimental, simulando um hemi-arco desdentado, referente aos elementos 15 ao 18, reabilitados com análogos de implantes osseointegrados, na posição dos elementos 15 e 17, e um corpo de prova simulando uma prótese parcial fixa metálica constituída de liga de Níquel-Cromo (Ni-Cr), com os pônticos localizados nos elementos 16 e 18, sendo este último com extensão em cantilever. Na região cervical dos análogos e cervicais dos pilares, foram fixados quatro extensômetros um em cada face, mesial, distal, vestibular e palatina. No corpo de prova foram fixados quatro extensômetros na cervical da prótese. O corpo de prova foi submetido a um teste de cargas axiais controladas, utilizando o sistema de aquisição de dados AqDados e AqDAnalysis (ADS0500IP- Lynx). Os ensaios mecânicos, com cargas estáticas compressivas axiais de 150N, foram realizados em máquina universal de ensaio DL EMIC 2000 0,5mm/min. Os resultados obtidos neste estudo mostraram que todos os componentes avaliados apresentaram valores consistentes de deformação por compressão e/ou tração, em função do carregamento aplicado (p<0,0001). Desta forma, foi possível concluir que as deformações observadas entre a região cervical do corpo de prova, pilares protéticos e análogos de implantes foram significativamente diferentes entre si (p<0,005 ou p<0,001), e que os fenômenos mecânicos observados foram de natureza deflectiva com características de compressão e tração. As comparações realizadas no plano horizontal mostraram diferenças estatisticamente significantes, na região dos análogos dos implantes, e as comparações realizadas no plano vertical exibiram diferenças significativas entre os componentes do sistema de um dos análogos estudados / Abstract: This study in vitro aimed to evaluate the deformation of implants and prosthetic components of implant-fixed partial denture, subjected to axial loads by means of strain gages. We made an experimental model simulating a hemi-arch edentulous, referring to the elements 15 to 18, similar rehabilitated with osseointegrated implants in the position of the elements 15 and 17, and a sample simulating a fixed partial denture metal alloy consisting of Nickel-Chromium (Ni-Cr), with elements located in pontics 16 and 18, the latter extending in cantilever. In the cervical region of the pillar analogs and neck, four strain gauges were attached one on each side, mesial, distal, buccal and palatal. In the sample have been set in four strain gages neck of the prosthesis, two strain gages under the pontic element and under the region on the cantilever. The sample has been subjected to an axial load controlled test, using the data acquisition system and AqDados AqDAnalysis (ADS0500IP-Lynx). The mechanical tests with static compressive axial 150N, were performed on universal testing machine EMIC DL 2000 0.5 mm / min. The results of this study showed that all components evaluated had consistent values of compression set and / or traction as a function of applied load (P <0.0001). Thus, was possible to conclude that the observed deformations of the cervical region of the body of evidence, pillars and similar prosthetic implants were significantly different (P <0.005 or 0.001), and the mechanical phenomena observed in nature were deflected with characteristics of compression and tension. The comparisons made in the horizontal plane showed statistically significant differences in the analogous region of the implants, and the comparisons made in the vertical plane showed significant differences between the system components of a similar study / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Orientador: Solange Maria de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T06:56:36Z (GMT). No. of bitstreams: 1 Barbosa_GabriellaLopesdeRezende_M.pdf: 1476954 bytes, checksum: 655317fdf41b3d0e2548c438c0fe7358 (MD5) Previous issue date: 2012 / Resumo: Os objetivos deste estudo foram comparar as mensurações lineares referentes à altura óssea palatina na região de primeiros pré-molares superiores para inserção de miniimplantes palatinos por meio de imagens de telerradiografia em norma lateral (TNL), tomografia computadorizada de feixe cônico (TCFC) e telerradiografia reconstruída do exame tomográfico (telerradiografia virtual); assim como comparar as alturas ósseas das regiões medianas e paramedianas do sítio avaliado. Para tanto, foram utilizadas 110 imagens de TNL, telerradiografia virtual e TCFC, dos mesmos pacientes. Para avaliação das alturas nas imagens, foi realizada mensuração da distância entre a intersecção do longo eixo do primeiro pré-molar com o assoalho do palato duro e o assoalho nasal, a qual correspondeu à dimensão do osso disponível para inserção de mini-implantes de ancoragem. Para avaliação das alturas medianas e paramedianas no corte tomográfico na região de primeiro pré-molar, foram realizadas mensurações da distância entre a camada cortical do assoalho nasal e a cortical do palato duro nos sítios central, 3 mm à direita e à esquerda, 6 mm à direita e à esquerda. As mensurações foram realizadas por três avaliadores. Os valores encontrados da TNL não diferiram estatisticamente (p>0,05) da TCFC (padrão-ouro), sendo comparáveis aos do exame tomográfico. Já os valores da telerradiografia virtual diferiram estatisticamente (p<0,05) tanto da TCFC quanto da TNL, sendo medidas subestimadas quando comparadas ao padrão-ouro e à técnica radiográfica. Quando comparadas as medidas dos sítios avaliados, não houve diferença estatística (p>0,05) entre as alturas paramedianas e a central. Concluiu-se que as mensurações realizadas para planejamento de inserções de mini-implantes palatinos na região dos primeiros prémolares são comparáveis nos exames de TNL e em reconstruções multiplanares de TCFC, e subestimadas nos exames de telerradiografia virtual. Concluiu-se também que as regiões paramedianas bilaterais a 3mm e 6mm da sutura palatina na região avaliada possuem altura óssea comparável à região mediana do palato / Abstract: The aims of this study were to compare linear measurements related to the palatal bone thickness in the region of first premolars to insert palatal mini-implants on images of conventional lateral radiography (CLR), cone beam computed tomography (CBCT) and reconstructed radiography from CBCT scan (virtual radiograph), as well as compare the thickness of the bone regions of the median and paramedian site assessed. For this purpose, 110 images of CLR, virtual radiography and CBCT of the same patient were used. To evaluate the thicknesses on the images, measurements was performed between the distance of the intersection of the long axis of the first premolar to the hard palate floor and nasal floor, which corresponded to the relevant dimension of available bone for insertion of mini-implants. To evaluate the thickness in median and paramedian regions on CT slice in the region of first premolar, measurements were made between the cortical layer of the nasal floor and hard palate, on central site and paramedian sites 3 mm and 6 mm bilaterally. The measurements were performed by three evaluators. The values found on TNL were not statistically different (p> 0.05) of CBCT (gold standard).The values of the virtual radiography were statistically different (p <0.05) from CBCT and TNL, being underestimated when compared to the gold standard and the radiographic technique. When comparing the measurements of the sites studied, there was no statistical difference (p> 0.05) between the thicknesses of the central site and paramedian sites. It was concluded that the measurements made for planning palatal mini-implants, at the level of the first premolars, is comparable on TNL and multiplanar reconstructions of CBCT, while underestimated in virtual radiography examinations. It is also concluded that the bilateral paramedian regions at 3mm and 6mm from the palatal suture, in the region evaluated, have bone thickness comparable to the median region of the palate / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica

Orientador: Renata Cunha Matheus Rodrigues Garcia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T19:03:37Z (GMT). No. of bitstreams: 1 Campos_CamilaHeitor_M.pdf: 2422429 bytes, checksum: 76c19be5f9518ea87df73f84487061c9 (MD5) Previous issue date: 2012 / Resumo: A reabilitação de arcos parcialmente dentados por meio de próteses parciais removíveis (PPR), sobretudo aqueles com ausência de dentes posteriores, apresentam limitações relativas ao suporte da prótese, que nestes casos é dividido entre dentes e mucosa, estruturas com diferentes resiliências. A associação de implantes osseointegrados à base da PPR tem como proposta atenuar estas limitações e trazer benefícios para o paciente, porém, a literatura sobre este assunto é escassa. Desta forma, este estudo se propôs a avaliar o efeito da associação de implantes osseointegrados pela adição de encaixe posterior implanto-retido à base de PPR mandibulares sobre o limiar de deglutição e ingestão de nutrientes. Oito voluntários (idade média = 60,1 ± 6,6 anos) apresentando edentulismo total maxilar e parcial mandibular (Classe I de Kennedy) foram selecionados e reabilitados com próteses totais (PT) maxilares e PPR mandibulares. Após dois meses de uso das novas próteses, as variáveis acima citadas foram mensuradas. Em uma segunda etapa, os mesmos voluntários receberam dois implantes osseointegrados bilaterais na região de molares inferiores. Após o período de osseointegração, foram adicionados encaixes do tipo bola aos implantes e à base da PPR, e após dois meses de uso das PPR implanto-retidas as variáveis foram novamente mensuradas. O limiar de deglutição foi avaliado por meio da contagem do número de ciclos mastigatórios realizados para a mastigação de uma porção de amendoim até o paciente sentir que está na iminência de deglutir. Foi ainda realizado o cálculo do tamanho mediano de partículas trituradas (X50), utilizando o material teste mastigável Optocal, pelo método de fracionamento de peneiras. O estado nutricional foi avaliado por meio de diário alimentar de três dias, e posteriormente foi traduzido em valores nutricionais por meio da utilização da Tabela Brasileira de Composição de Alimentos. Foram realizadas análises comparativas pareadas, sendo utilizados os testes T de Student e Wilcoxon para nível de significância de 5%. Embora não tenha ocorrido mudança no número de ciclos mastigatórios necessários à deglutição após a inserção do encaixe implanto-retido (P>0,05), houve redução significativa do X50 (P<0,05). Observou-se, ainda, aumento na ingestão de calorias (P=0,008) e no consumo diário de carboidratos (P=0,003), proteína (P=0,023), cálcio (P=0,006), fibras (P=0,040) e ferro (P=0,038). Não foram detectadas alterações na ingestão de gordura e no IMC (P>0,05). Pode-se concluir que a associação de implantes às PPR por meio encaixe do tipo bola apresenta efeito positivo sobre a mastigação e ingestão de nutrientes em pacientes com arcos Classe I de Kennedy / Abstract: The rehabilitation of partially dentate arches with removable partial dentures (RPD), especially those with absence of posterior teeth, have limitations regarding RPD support, divided between teeth and mucosa, with different structures resilience. The association of dental implants beneath RPD base proposal is to reduce these limitations and bring benefits to patients; however, the literature on this is scarce. Therefore, this study aimed to assess the impact of the use of a posterior implant retainer for free-end RPD on the swallowing threshold and nutrient intake. For this purpose, eight volunteers (mean age = 60.1 ± 6.6 years) presenting maxillary edentulism and mandibular partially dentate arch (Kennedy Class I) were selected and rehabilitated with maxillary complete dentures (PT) and mandibular RPD. After two months of use of the new prosthesis, the variables were measured. In a second step, the same volunteers received two osseointegrated implants, bilaterally in the region of mandibular first molars. After healing time, ball attachments were added to the implants and fitted on the RPD base, providing retention, and after two months of using, the variables were again measured. The swallowing threshold was assessed by counting the number of masticatory cycles and by calculating the median particle size reduction (X50). The number of masticatory cycles performed for chewing a portion of peanuts until the patient felt need to swallow was registered by the researcher. The X50 value was determined by sieve fractioning method using the chewable test material Optocal. Nutritional state was assessed by three-day food diary and further compared to the Brazilian Food Composition Table. Comparative analyzes were made by using the Paired Student's t-test and Wilcoxon Rank-test, depending on the normality distribution of data, and for 5% of significance level. Although there was no change in the number of chewing cycles needed to swallow after implant insertion (P>0.05), there was a significant reduction in the average size of the particle to be swallowed (P<0.05). There was also an increase in energy intake (P=0.008) and daily consumption of carbohydrates (P=0.003), protein (P=0.023), calcium (P=0.006), fiber (P=0.040) and iron (P=0.038). No changes were detected in fat intake and BMI (P>0.05). It can be concluded that the association of implants to RPD by ball attachment insertion may have positive effect on chewing and nutrient intake in patients with Class I Kennedy arches / Mestrado / Protese Dental / Mestra em Clínica Odontológica

Orientadores: Enilson Antonio Sallum, Francisco Humberto Nociti Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:11:36Z (GMT). No. of bitstreams: 1 Carvalho_MarceloDiniz_M.pdf: 838460 bytes, checksum: d0aff5d2298e732ab336cd58428d002a (MD5) Previous issue date: 2005 / Resumo: O objetivo do presente estudo foi avaliar a influência da fumaça de cigarro na presença da deficiência de estrógeno sobre o reparo ósseo ao redor de implantes de titânio. Foram utilizadas 45 ratas (Wistar) divididas em 3 grupos: ovariectomia simulada (SHAM, n=15), ovariectomia (OVX, n=15) e exposição a fumaça de cigarro (EFM) associada a OVX (EFM+OVX, n=15). No grupo EFM+OVX, a EFM iniciou-se 60 dias antes da colocação dos implantes e manteve-se até o fim do período experimental. Todos animais receberam um implante em uma das tíbias e no mesmo período cirúrgico foram realizadas as OVX e SHAM. Sessenta dias após as cirurgias, os animais foram mortos e secções não descalcificadas obtidas para avaliação dos seguintes parâmetros: porcentagem de osso na região adjacente ao implante (500 µm) (OA), porcentagem de preenchimento ósseo dentro dos limites das roscas de cada implante (PR) e porcentagem de contato ósseo direto com a superfície do implante (CD). As medidas foram obtidas separadamente para região A (cortical) e B (medular). Os resultados deste estudo mostraram que, na região A, o grupo EFM+OVX apresentou uma menor OA e um menor CD quando comparado aos outros grupos (p<0,05). Na região B, menores valores de CD e OA foram observados no grupo EFM+OVX, seguidos dos grupos OVX e SHAM, respectivamente (p<0,05). Já para PR, os grupos EFM+OVX e OVX se comportaram de maneira semelhante diferindo do grupo SHAM (p<0,05). Conclui-se que, dentro dos limites deste estudo, a exposição à fumaça de cigarro amplificou os efeitos da deficiência de estrógeno, prejudicando a qualidade e o reparo ósseo ao redor de implantes de titânio inseridos em tíbias de ratas ovariectomizadas / Abstract: Background: Smoking has been considered one of the main risk factors for osteoporosis. Cigarette smoke inhalation and estrogen deficiency have been proving to negatively affect bone healing around titanium implants. Thus, the purpose of this study was to investigate the effect of cigarette smoking inhalation on bone around titanium implants in estrogen deficiency rats. Methods: Fourth-five female wistar rats had the tibia surface exposed for the placement of a screw-shaped titanium implant (4.0mm in length; 2.2mm in diameter). The animals were randomly assigned to group SHAM (sham operated rats / n=15), group OVX (ovarectomized rats / n=15) and group CSI+OVX (2 months of intermittent cigarette smoke inhalation (CSI) prior and 2 months after implant placement in ovariectomized rats/ n=15). The implants were placed at the same time of OVX or Sham surgery. After 60 days the animals were sacrificed and undecalcified sections obtained. Percentage of bone in a 500mm-wide zone lateral to the implant (BO), bone filling within the limits of the threads (BF) and bone-to-implant contact (BC) was measured in cortical (zone A) and cancellous (zone B) bone separately. Results: Data analysis showed that, in zone A, a decreased BO and BC was observed for CSI+OVX (p <0.05). In zone B, the CSI+OVX group showed the lowest values for BO and BC, followed by groups OVX and SHAM, respectively (p<0.05). Similar values of BF were observed for CSI+OVX and OVX groups, that were lower than the ones obtained by SHAM group (p <0.05). Conclusion: Within the limits of the present investigation, cigarette smoke inhalation amplified the effects of estrogen deficiency on bone around titanium implants inserted in ovariectomized rats / Mestrado / Periodontia / Mestre em Clínica Odontológica

Orientador: Mauro A.A. Nobilo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:50:29Z (GMT). No. of bitstreams: 1 Bastos_PolianaLima_M.pdf: 3116472 bytes, checksum: 1ef54b4bfd3a59b4b3d79ac8ff9a99e7 (MD5) Previous issue date: 2005 / Resumo: Este trabalho avaliou, por meio de análise fotoelástica, a distribuição de tensões ao redor de implantes que suportam próteses totais fixas. O modelo foi confeccionado com resina fotoelástica PL-2 (Vishay Measurements Group, USA), onde foram posicionados seis implantes de 3,75 X 11mm (Conect AR, Conexão Sistemas de Prótese, São Paulo, SP). Foram avaliadas dois sistemas de próteses totais fixas: o protocolo convencional de Brânemark , onde foi confeccionada uma estrutura em titânio (GI) e a prótese fixa destacável (Gil), também confeccionada em titânio, com acréscimo de dois attachments (MK1 Universal Attachments, Sande, Germany). Para os dois grupos, utilizou-se a técnica do cilindro cimentado, na qual cilindros pré-fabricados foram cimentados à estrutura metálica. Inicialmente, as estruturas foram avaliadas quanto às discrepâncias marginais em microscópio óptico com precisão de 0,5/lm e aumento de 120x (UHL VMM-100-BT; Renishaw; UK) associado a um equipamento de leitura digital (Quadra-Check 200; Metronics Inc, Canadá). O método fotoelástico com polariscópio circular foi utilizado para avaliar a distribuição de tensões após prova da estrutura metálica e instalação da prótese, bem como para registrar esse comportamento, por meio de fotografias. Um carregamento oclusal de 100N foi aplicado em 3 pontos individualmente: A (região distal do segundo pré-molar direito), B (regiãodistal do segundo pré-molar esquerdo) e C (região palatina, entre os incisivos centrais). Para as discrepâncias marginais, o GI exibiu menor desajuste (52,1Oum) em relação ao Gil (66, 49um). Os resultados fotoelásticos não mostraram diferenças significativas entre os dois grupos. Observou-se maior concentração de tensões na cervical, no corpo e no ápice dos implantes anteriores, enquanto que nos implantes posteriores, houve maior concentração na região apical. Além disso, o padrão de franjas aumentou gradativamente como resultado da seqüência dos procedimentos laboratoriais. A distribuição de tensões mostrou-se similar entre a prótese do tipo protocolo convencional de Brânemark e a prótese fixa destacável / Abstract: The present study evaluated the stress distribution around osseointegrated implants restored with complete fixed dentures by photoelastic analysis. A photoelastic model of an edentulous maxilla was fabricated (PL-2; Vishay Measurements Group, USA) with 6 implants 3.75x11mm (Conect AR; Conexao Sistema de Protese, Sao Paulo, Brazil). Two complete fixed dentures were evaluated: the conventional Branemark protocol-type rehabilitation technique (GI) with cast titanium framework; and, a fixed-detachable denture (Gil) made from cast titanium incorporating 2 attachments (MK1 Universal Attachments, Sande, Germany). For both groups, the frameworks were manufactured using the cemented-cylinder incorporation technique, where pre-fabricated prosthetic cylinders were cemented to the castings. Initially, ali the frameworks were evaluated for marginal discrepancies in a 0.5mm-accurate optical traveling microscope x120 magnification (UHL VMM-100-BT; Renishaw, UK) equipped wit a digital measurement read-out system (Quadra-Check 200; Metronics Inc, Canada). The photoelastic method with a circular polariscope was used to evaluate the stress distribution after the try-in and installation of the frameworks on the implants. Loads of 100 N were applied to specific points of the frameworks: A (right posterior second pre-molar), B (left posterior second pre-molar) and C (palatal to central incisors). Photographs were taken from the photoelastic fringes after loading around the implants with different magnifications. For marginal discrepancies, the GI exhibited lower gaps (52.10um) than Gil (66.49um). Regarding to the stress distribution, no significant differences were found between the groups. A transfer of load was observed in apical, distal and mesial regions in the anterior implants. For posterior implants, stress was concentrated in the apical regions. The tensions produced around the implants were gradually increased as the laboratorial procedures were accomplished. Stress distribution was similar to conventional Branemark protocoltype and fixed-detachable dentures / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Orientador: Renato Mazzonetto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T05:20:15Z (GMT). No. of bitstreams: 1 Silva_FabricioMoreiraSerrae_M.pdf: 19777334 bytes, checksum: d899078a1e3b8b446e2af4128bdc2219 (MD5) Previous issue date: 2005 / Resumo: O presente estudo teve como objetivo avaliar clinica e histologicamente o comportamento da associação entre uma matriz óssea orgânica bovina (Gen-Ox@) e uma proteína óssea morfogenética (BMP) derivada de embrião bovino (Gen-Pro@), quando comparada com enxerto ósseo autógeno em cirurgias para levantamento bilateral de seio maxilar. Foram operados 10 pacientes não-fumantes e sem alterações sistêmicas, que necessitavam de enxerto bilateral do seio maxilar para futura colocação de implantes osseointegráveis. Em todos os pacientes, foi selecionado um lado como teste e o contra-lateral como controle. Após um período de 6 a 11 meses, foi realizada avaliação clínica da área enxertada e biópsia com broca trefina de 2mm, em região adjacente ao eixo do implante a ser inserido. Os espécimes foram armazenados em formol a 10% e levados para processamento laboratorial para coloração das peças com hematoxilina-eosina e confecção das lâminas. A análise histológica foi realizada por meio de microscopia óptica. Clinicamente, pôde-se observar que a qualidade e quantidade óssea formada no lado preenchido com enxerto autógeno apresentaram um aspecto mais favorável à instalação dos implantes, podendo-se observar uma formação óssea mais completa. Histologicamente, pôde-se observar um padrão de neoformação óssea diferente, com o osso autógeno apresentando um aspecto mais organizado. Com o presente estudo, pôde-se concluir que, clinica e histologicamente, o padrão de formação óssea das áreas enxertadas com a associação de osso heterógeno bovino e proteína óssea morfogenética bovina apresenta um trabeculado ósseo menos compacto e menos organizado do que o osso autógeno / Abstract: The present study aimed to evaluate clinically and histologically the behavior of the association between bovine organic osseous matrix (Gen-Ox@) and bone morphogenetic protein (BMP) (Gen-Pro@), when compared with autogenous bone graft in bilateral maxillary sinus lift procedures. Ten non-smoking and systemically healthy patients who needed bilateral maxillary sinus grafting for the placement of osseointegrated implants were operated. In ali patients, one side was selected as test and the other as control. In a second surgical intervention, the implant placement was preceded by clinical evaluation and biopsy of the lateral sinus wall using with a 2 mm trefine bur, in the region of the bone wall created in the sinus lift procedure. The specimens were stored in 10% formalin and taken to laboratorial processing for hematoxicilin-eosin dying and section preparation. The histological analysis was performed through optical microscopy. Clinically, a better bone formation pattern could be observed in the side grafted with autogenous bone. Histologically, the bone neoformation pattern was different in both sides. In the present study, the association with BMP as a growth factor showed different results when compared to autogenous graft. With the present study, it was possible to conclude that clinically the bone formation pattern is better and more full when autogenous bone is used. Histologically, less compact and less organized bone pattern than with the autogenous bone were found / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica

Abstract The improvement of implant biocompatibility is constantly under investigation. Titanium is a standard biomaterial that performs well in dental and orthopedic implantations. However, detrimental adverse effects resulting from e.g. biomaterial properties, inflammatory responses and surgical procedures occasionally occur. Coating the biomaterials aims at increasing the proportion of successful operations. Pectins, large plant cell wall polysaccharides, are innovative, modifiable, and potentially anti-inflammatory candidates for biomaterial nanocoatings. In this thesis, covalently-grafted pectin fragments (modified hairy regions, MHRs) modified either in vitro (from apple) or in vivo (from potato) were tested. Cell culture vessels and titanium substratum coated with the apple-MHRs, MHR-A and a further-tailored fragment type, MHR-B, were compared with controls for their ability to support proliferation and differentiation of osteoclasts and osteoblasts. Cells grew and differentiated on MHR-B and on the control surfaces; MHR-A did not perform well in these assays. Genetically-engineered potato MHRs did not support bone cell growth to the same extent as apple MHR-B, but nonetheless the possibility to manipulate cellular proliferation with specific in vivo – modifications of pectins was introduced. When implanted into rat soft tissues, neither of the apple MHRs provoked severe acute inflammatory reactions, which indicates good in vivo - tolerance of these botanical macromolecules. These studies illustrate the biocompatibility of MHRs, and the directions towards which they could be further tailored. In terms of clinical use, their tolerability in vivo is especially significant.

Abstract A new animal model was developed to evaluate the effect of bovine native bone morphogenetic protein (BMP) on the healing of segmental, critical-sized bone defects. Laboratory-bred adult beagle dogs were used in the study. A 2 cm corticoperiosteal defect was created using an oscillating saw in mid-ulna, and the defect was treated with bone grafts and implants fixed by an intramedullary Kirschner wire through predrilled holes in the middle of the implant. Plate and screw fixation was also used in some groups. Coral, hydroxyapatite and demineralized xenograft bone were placed in the defects with or without BMP. Autografts and allografts were used as controls. The BMP was extracted from bovine diaphyseal bone. The follow-up period was 36 weeks. Radiographs were taken at regular intervals during the follow-up period, and bone formation and bone union were evaluated. The radiographs were digitized, and callus was measured and CT scans obtained to define bone density. At the end of the study, the bones were harvested and tested mechanically in a torsion machine until failure. After mechanical testing, the bones were reconstructed and histological sections were made. With autograft and allograft bone grafts, healing was nearly complete. Hydroxyapatite and demineralized xenograft bone did not result in healing of the bone defect, while coral enhanced bone formation, but the healing was not comparable to autografts or allografts. Hydroxyapatite implants did not resorb during the 36 weeks of follow-up to enhance bone healing, and there was a fibrous capsule around the hydroxyapatite implants in histology. Xenograft bone was resorbed, and very little bone formation and extensive fibrosis were seen at the implant site. Coral was resorbed and gradually replaced by new bone, but did not heal the defect completely. With every implant, added BMP had a positive effect on healing as evaluated either radiographically, mechanically or histologically. Coral was the most optimal carrier material for BMP among the materials tested in this study. The animal model seems to be suitable for studying the healing of bone defects, as all the animals were physically active from the first postoperative day and did not seem to have problems with motion during the follow-up period. Intramedullary fixation lacks rotational stability, which may have a negative effect on healing. The bones fixed with a plate and screws showed better scores in radiographs and were mechanically stronger, although the study groups were too small to allow definitive conclusions. As a conclusion, none of the transplants or implants were equally efficient as cortical autograft in healing segmental ulnar defects. BMP did not enhance the poor capacity of hydroxyapatite and xenograft bone to heal the bone defect. According to the present findings, the composite implant consisting of coral and BMP seemed to be the best of the composite implants tested.

Implants such as intramedullary nails or cancellous screws are used to mechanically stabilize fractures in bone. They provide reinforcement to the bone if they find good purchase in cancellous bone. Not all implants hold enough loads for mechanical stability and pull-out or cut-out may happen in some cases. This is linked to the interface between the bone and the implant. Computer modelling techniques are used to investigate both the effects of cut-out in a femur model, and the pull-out forces of cancellous bone screws. The bone geometry was based on CT scanned cancellous bone and converted using Mimics® software. The finite element models were produced in ANSYS®. Simple bone models were used to examine a fractured femur under standard gait loading. These models were continuum models and idealised the screw to bone interface in order to ease computational demand. The models were used to investigate the ideal positions of intramedullary devices lag screws on an anterior-posterior view of the implant location. In accordance with literature, an inferior-central or central-central position was the best position of the lag screw, while a superior-anterior or inferior-anterior position was adverse. The introduction of multi-scale modelling in order to investigate cut-out with a discrete bone model was not achieved. Discrete cancellous bone models were used to examine some of the cancellous screw characteristics, including pitch, inner diameter and proximal half angle, while a cancellous screw was also studied using a model of cancellous bone with a range of bone densities. The calculated reaction force for a pull-out of 0.2mm shows the influence of some parameters. Change in the proximal half angle increased the stiffness and strength by about 15% in line with the experimental findings of others, while apparent density changes of 2.5% increased the forces threefold. A significant reduction in reaction force was observed when a particular screw geometry in lower apparent density bone was modelled and rotated through 180° on a plane. Examination of the geometry of the bone/screw interface shows that in certain positions there is very little cancellous bone to support the implant. This will lead to low strength and is very difficult to predict. The same models were used to examine the effect of increasing bone stiffness adjacent to the implant and the use of a cement layer to augment the screw model. The increasing stiffness concluded that an increase in pull-out stiffness can be achieved, even in low quality bone, while the cement augmentation showed a significant increase in pull-out strength, though it was idealised as bonded to the bone and screw.

Although the infectious initiation of peri-implantitis is commonly accepted, differences in microbial composition in peri-implantitis and periodontitis has been the subject of some debate. The presence of periodontal pathogens at sites with peri-implantitis has been documented by many studies. However, other studies have revealed that sites with peri-implantitis harbour high levels of microorganisms which have not primarily been associated with periodontitis, such as Candida-, Staphylococcus- and Enterobacteriaceae species. These findings suggest that peri-implantitis may display a flora distinct from that of periodontitis. The aim of the present study was to evaluate the presence of three known periodontal pathogens, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis) and Treponema denticola (T. denticola) at healthy and diseased (peri-implantitis) sites. A second aim was to evaluate the presence of Candida-, Staphylococcus- and Enterobacteriaceae-species at the same sites. The hypothesis was that A. actinomycetemcomitans, P. gingivalis, T. denticola, Candida-, Staphylococcus- and Enterobacteriaceae-species would be detected at higher levels in peri-implantitis samples than healthy controls. Samples of peri-implant crevicular fluid (PICF) were obtained from peri-implant pockets in 13 subjects, of which 5 subjects had both healthy and diseased implants, 4 subjects had healthy implants only and the remaining 4 had only diseased implants. Microbial analyses were carried out using Real Time PCR and microbial culture techniques. A. actinomycetemscomitans, P. gingivalis and T. denticola were detected at higher levels at sites with peri-implantitis compared to healthy sites. Furthermore, Klebsiella oxytoca was detected in one peri-implantitis sample whereas Candida- and Staphylococcus species were not detected in any of the samples. Higher counts of periodontal pathogens were detected around implants with peri-implantitis. The suggestion that Candida and Staphylococcus may be present at higher levels in peri-implantitis was not supported by this study as these bacteria could not be detected in any of the samples.