Introdução: Após a exodontia, a cicatrização natural do alvéolo provoca alterações dimensionais no rebordo alveolar, com diminuição dos tecidos moles e duros. Diferentes técnicas podem ser utilizadas para tentar diminuir essas alterações, com a intenção de facilitar a reabilitação estética e funcional com implantes, principalmente em áreas de dentes anteriores. Objetivos: Os objetivos deste estudo foram verificar a eficácia da utilização do material de origem xenógena Orthogen® na preservação do rebordo alveolar pós-exodontia e avaliar as características histológicas após 4 meses de reparo. Materiais e Métodos: 20 pacientes foram divididos aleatoriamente em 2 grupos, de acordo com a abordagem que iriam receber após a exodontia de uma raiz residual. No grupo teste, os alvéolos foram preenchidos com Orthogen® e selados com EGL (Enxerto Gengival Livre). No grupo controle, um coágulo foi preservado no alvéolo e o mesmo também foi selado com EGL, sem a utilização do Orthogen®. Em ambos os grupos as exodontias foram realizadas de maneira minimamente traumática, com o Kit de Extração Atraumática Neodent®. Modelos de gesso obtidos antes das exodontias (tempo 1) e após 4 meses (tempo 2), momentos antes da instalação dos implantes, foram utilizadas para as medidas dimensionais, através do escanemento dos modelos e medidas no programa Orthoanalyzer®. Amostras ósseas obtidas após 4 meses de reparo foram utilizadas para a análise histológica descritiva. Resultados: Os resultados demonstraram que, após 4 meses de reparo alveolar, os dois grupos apresentaram remodelação do rebordo alveolar e diminuição nas medidas realizadas. Porém, a remodelação do rebordo foi mais evidente no grupo controle (coágulo). Histologicamente foi possível observar formação de novo osso ao redor das partículas do Orthogen®. Conclusões: A utilização do Orthogen® para preenchimento dos alvéolos e preservação do rebordo alveolar foi eficaz na diminuição das alterações dimensionais nos tecidos duro e mole do rebordo alveolar pós-exodontia. / Introduction: After tooth extraction, the natural healing of the socket is followed by dimensional changes of ridge contour, with marked reduce of hard and soft tissues. Socket reservation techniques can be used to improve functional and esthetics of the dental implants in this areas, especially in anterior teeth areas. Objectives: The aims of this study are to verify the efficacy of use Orthogen® to ridge preservation and analysis the histological characteristics after 4 months repair of the sockets. Material and Methods: 20 patients were randomly distributed in 2 groups, according with the treatments. In test group, the sockets were filled with Orthogen® and closed with a gingival free graft. In control group, the clots were preserved into the socket and free gingival graft was sutured in the deepithelialized marginal tissue of the socket. Stone casts were used to analyze the ridge dimensional changes with the Orthoanalyzer® software. After 4 months, bone samples were obtained during the dental implant procedure and were used to describe the histological characteristics. Results: The results showed that, after 4 months of wound healing, both groups showed a decrease in the measurements. However, the remodeling of the ridge was most evident in the control group (clot). Histological images showed the formation of new bone around the Orthogen® particles. Conclusion: The use of Orthogen® to socket preservation can collaborate to reduce the dimensional changes of the hard and soft tissue in post-extraction alveolar ridge sites.

O objetivo desse estudo foi descrever o padrão de reparação da ROG, após o uso de osso autógeno e membrana de colágeno suíno (BioGide). Foram utilizados 30 ratos machos Wistar, nos quais 30 mini-implantes fixaram enxerto ósseo autógeno do tipo onlay, originário de osso parietal, na região do ângulo da mandíbula. Os enxertos foram recobertos com membranas de colágeno e os animais sacrificados nos períodos de zero hora, 14, 21, 45 e 150 dias. As amostras foram descalcificadas e processadas pela técnica de fratura (Berglundh et al., 1991). Após 2 semanas, a interface entre o leito e o enxerto encontrava-se preenchida por tecido conjuntivo imaturo rico em vasos e fibroblastos. Aos 21 dias, observou-se osso neoformado sob a membrana e junto aos bordos do enxerto, integrando o enxerto ao leito. Este apresentava intensa remodelação, de modo que junto às fresas do implante observamos osso imaturo e vasos. Aos 45 dias, a estrutura colágena original da membrana apresentou avançado grau de reabsorção e diminuição da sua espessura. O tecido ósseo formado sob a membrana demonstrou início de organização lamelar. No período final, após 150 dias, o enxerto apresentou-se completamente integrado ao osso receptor e com adiantado grau de maturação. Conclui-se que após 21 dias, o osso neoformado estava em contato com o enxerto e o implante. No período de 45 dias, observou-se maturação inicial do tecido ósseo e avançada biodegradação da membrana. Apenas após 150 dias, pudemos assegurar a integração do enxerto ao osso neoformado na região do leito, com ganho adicional de tecido ósseo. / The aim of the present study was to evaluate the repair pattern after guided bone regeneration (GBR), using an autogenous bone graft covered with a porcine collagen membrane (BioGide). Thirty male Wistar rats received an onlay autogenous bone graft, harvested from parietal bone, laid on the external area near the angle of the mandible with titanium fixtures. The grafts were covered with a collagen membrane and the animals were sacrificed at 0 hour, 14, 21, 45 and 150 days. Decalcified sections were prepared according to the fracture technique (Berglundh et al., 1991). After two weeks, the bed-graft interface presented an immature connective tissue layer, containing fibroblasts-like cells and vessels. After 21 days, under the membrane, newly formed trabecular bone established bridges connecting the bed and the lateral borders of the graft. The receptor bed showed intense remodeling and adjacent to the implant threads, immature bone and vessels could be seen. After 45 days, the collagen structure of the membrane presented extensive resorption and a large decrease in thickness. The bone tissue, under the membrane, exhibited initial lamellar bone arrangement. After 150 days, a complete fusion of the graft with the receptor bed and an advanced level of bone maturity of the graft were observed. It was concluded that, after 21 days, the newly formed bone was in direct contact both with the graft and the implant. At 45 days the porcine collagen membrane showed advanced stage of resorption and an initial bone maturity could be observed. Only at 150 days, we could assure the graft integration to the newly formed bone at bed receptor area, with additional bone tissue gain.

The objective of this thesis was to investigate the role of hydroxyapatite and silicate-substituted hydroxyapatite synthetic bone graft substitute (SBG) material properties in modulating the processes of protein adsorption and desorption, and their combined role in the subsequent regulation of cell attachment, proliferation and differentiation on the surfaces of these materials in vitro. As a result of their purported role in promoting osteogenic behaviour in vivo the materials parameters selected for investigation were chemistry (stoichiometric hydroxyapatite (HA) versus 0.8wt% silicate-substituted hydroxyapatite (SA)) and strut porosity (20% versus 30% strut porosity). Cell attachment and response to different SBG was assessed to samples in the ‘as received’ condition as well as after a series of sequentially varied pre-treatments with solutions of phosphate buffered saline or cell culture media either unsupplemented or in combination with mixed serum proteins and/or Fibronectin (Fn). This enabled investigation of the effect of sample chemistry and strut porosity on mixed serum protein interactions and Fn adsorption under both competitive and non-competitive conditions, and the study of subsequent regulation of cell attachment and response as a consequence of pre-treatment. Results showed that serum protein interactions were key to modulation of cell response to chemistry, and there was evidence that for Fn this may be related to conformational changes in the adsorbed protein rather than its level of enrichment in the protein interlayer. In terms of the materials properties investigated strut porosity was found to be the most dominant factor in the regulation of cell response, where SBG with 30% strut porosity promoted human mesenchymal stem cell (hMSC) osteoblastic differentiation. Moreover hMSC response to SBG with 30% strut porosity seemed to be less sensitive to pre-treatment. In conclusion, the results of these experiments indicate that strut porosity more directly influences the cellular response to HA and SA BGS than chemistry in vitro. Moreover, the role that Fn and other serum proteins have in regulating this response is dependent on the physiological environment and BGS chemistry.

Objetivo: o objetivo deste ensaio clínico controlado aleatorizado foi avaliar o uso de um substituto ósseo sintético associado a uma membrana de colágeno absorvível na preservação da crista óssea alveolar após extração dentária, por meio de análises clínica e tomográfica em humanos. Metodologia: Quatorze pacientes foram selecionados, cada um apresentando ao menos dois dentes anteriores maxilares indicados para extração: no Grupo Teste (GT), o alvéolo pós-exodontia foi preenchido pelo substituto ósseo sintético Reprobone, e no Grupo Controle (GC) houve o preenchimento do alvéolo apenas por coágulo. Em ambos os grupos os alvéolos foram cobertos por uma membrana absorvível de colágeno (BioMend), que por sua vez foi recoberta por um retalho mucoperióstico fechado oclusivamente. Tomografias computadorizadas do tipo Cone Beam foram realizadas no pós-operatório imediato e após 6 meses do procedimento cirúrgico, e as alterações dimensionais horizontais e verticais das cristas ósseas foram quantificadas. Para a análise estatística intragrupo utilizou-se o teste t pareado; para avaliações intergupo, teste t não pareado. Em todas as comparações foi adotado um nível de significância de 5%. Resultados: A Medida Vertical Vestibular reabsorveu 1,5 mm (ou 21,3%) da medida inicial no Grupo Teste (p<0,05) e 1,8 mm (ou 25,8%) no Grupo Controle (p<0,05). A Medida Vertical Palatina diminuiu 0,3 mm em ambos os grupos (p>0,05). A Altura Máxima reduziu 0,5 mm ou 7,9% no grupo com Reprobone e BioMend quando comparada ao baseline (p>0.05), e 1,1 mm ou 14,8% no grupo com BioMend apenas (p<0,05), sendo esta diferença intergrupo estatisticamente significante (p<0,05). A Medida Horizontal Apical diminuiu 0,2 mm no GT, o equivalente a 2,9% (p>0,05), enquanto que no GC diminuiu 0,5 mm ou 7,3% (p<0,05), não havendo diferença estatisticamente significante entre os grupos. A Medida Horizontal Cervical (MHC) perdeu 0,5 mm ou 7,2% no GT e 1,4 mm ou 15,1 % no GC: a análise intragrupo apontou diferença estatística entre os dados iniciais e após 6 meses para este parâmetro (p<0,05), em ambos os grupos, e também foi encontrada diferença estatisticamente significante na avaliação entre grupos para a MHC. Conclusão: Os resultados obtidos demonstraram que o uso do Reprobone associado à Biomend apresentou benefícios e melhores resultados na manutenção vertical e horizontal do rebordo alveolar em comparação ao uso apenas da membrana colágena. / Objective: The aim of this randomized controlled clinical trial was to evaluate the use of a synthetic bone substitute associated with an absorbable collagen membrane in preserving the alveolar crest after tooth extraction, through clinical and tomography analysis in humans. Methods: Fourteen patients were selected, each featuring at least two front teeth jaws indicated for extraction: in Test Group (TG), the post-extraction sockets were filled by the synthetic bone substitute ReproBone, and the control group (CG) was filling the alveoli only by clot. In both groups, the wells were covered with a resorbable collagen membrane (BioMend), which in turn was covered with a mucoperiosteal flap closed occlusally. CT Cone Beam type were performed in the immediate postoperative period and after 6 months of surgery, and the horizontal and vertical dimensional changes of the bone crests were quantified. For intra-group statistical analysis used the paired t test; to intergupo reviews, unpaired t test. In all comparisons was adopted a 5% significance level. Results: Vestibular Vertical Measure reabsorbed 1.5 mm (or 21.3%) of the original measure in the test group (p <0.05) and 1.8 mm (or 25.8%) in the control group (p <0 , 05). The Measured Vertical Palatine 0.3 mm decreased in both groups (p> 0.05). The Maximum Height reduced 0.5 mm or 7.9% for the ReproBone and BioMend compared to baseline (p> 0.05), and 1.1 mm or 14.8% for the BioMend only (p <0.05 ), statistically significant intergroup difference (p <0.05). Measure the horizontal apical decreased by 0.2 mm WG, equivalent to 2.9% (p> 0.05), whereas the CG 0.5 mm or decreased by 7.3% (p <0.05), not statistically significant difference between groups. The Horizontal Cervical Measure (MHC) lost 0.5 mm or 7.2% in GT and 1.4 mm or 15.1% of CG: the intra-group analysis showed statistical difference between the initial data and after 6 months for this parameter (p <0.05) in both groups, and was also a statistically significant difference between groups in the evaluation for the MHC. Conclusion: The results showed that the use of ReproBone associated with BioMend presented benefits and better results in vertical and horizontal maintenance of alveolar ridge compared to using only the collagen membrane.

Recentes estudos em animais tem demonstrado pronunciada reabsorção da tábua óssea vestibular, após a colocação de implantes imediatos. A realização de cirurgias sem retalho para a colocação de implantes imediatos, e a utilização de enxertos ósseos nos gaps, representam alternativas viáveis para minimizar a reabsorção da tábua óssea vestibular e, dessa forma, otimizar a osseointegração. O presente trabalho se propôs a investigar a remodelação da tábua óssea vestibular, associada ou não ao enxerto ósseo sintético no gap entre a superfície do implante e a tábua vestibular, em cirurgias sem retalho. Neste contexto, implantes posicionados ao nível da tábua óssea vestibular, e 2.0 mm subcrestal foram comparados. Metodologicamente, os pré-molares mandibulares bilaterais de 8 cães foram extraídos sem retalho, 4 implantes foram instalados nos alvéolos de cada lado, e posicionados 2.0 mm da tábua óssea vestibular originando o gap. Os seguintes grupos foram testados: implantes equicrestal associado com o enxerto ósseo sintético (grupo teste equicrestal-GTEC), implantes equicrestal com coágulo sanguíneo (grupo controle-GCEC), implantes 2.0 mm subcrestal associado com o enxerto ósseo sintético (grupo teste subcrestal-GTSC) e implantes 2.0 mm subcrestal com coágulo sanguíneo (grupo controle-GCSC). Uma semana após as cirurgias, próteses metálicas foram instaladas. Marcadores ósseos foram administrados 1, 2, 4 e 12 semanas após as cirurgias para a análise da fluorescência. Doze semanas após a colocação dos implantes os animais foram sacrificados. Para a análise radiográfica, cortes vestíbulo-linguais foram realizados nos blocos com os implantes individualizados, e imagens digitais radiográficas foram obtidas. Para a análise histomorfométrica, lâminas foram preparadas através dos blocos seccionados. A análise radiográfica revelou que o grupo teste subcrestal apresentou maior perda da tábua óssea vestibular com diferença estatisticamente significante quando comparado com os grupos equicrestais (p<0,05). Não foi observada diferença significativa entre os grupos em relação à distância linear, e a presença ou ausência de neoformação tecidual no gap residual. A avaliação histomorfométrica demonstrou resultados significativos para o grupo teste equicrestal, sem perda da tábua óssea vestibular. Em relação aos outros parâmetros, o grupo controle subcrestal apresentou melhores resultados. A nova formação de tecido ósseo foi determinada pela quantificação da fluorescência dos marcadores em áreas adjacentes e distantes às superfícies dos implantes. As áreas adjacentes mostraram diferentes resultados entre os grupos, e pequeno um decréscimo na 12a semana, exceto para o grupo controle subcrestal, que apresentou um aumento. As áreas distantes mostraram um aumento contínuo na formação óssea. Os implantes equicrestais apresentaram insignificativa perda da tábua óssea vestibular. No entanto, os implantes subcrestais mostraram maior perda da tábua óssea vestibular, mesmo com a presença do enxerto ósseo. No entanto, a tábua vestibular manteve-se sempre coronal ao ombro do implante. Ambos os grupos equicrestais e subcrestais testes e controles foram beneficiados nas fases iniciais do processo de formação óssea como evidenciado pela análise de fluorescência. / Recent studies in animals have shown pronounced resorption of the buccal bone plate after immediate implantation. The use of flapless surgical procedures prior to the installation of immediate implants, as well as the use of synthetic bone graft in the gaps represent viable alternatives to minimize buccal bone resorption and to favor osseointegration. The aim of this study was to evaluate the healing of the buccal bone plate following immediate implantation using the flapless approach, and compare this process with sites in which a synthetic bone graft was or was not inserted into the gap between the implant and the buccal bone plate. Lower bicuspids from 8 dogs were bilaterally extracted without the use of flaps and 4 implants were installed in the alveoli in each side of the mandible and were positioned 2.0 mm from the buccal bone plate (gap). Four groups were devised: 2.0 mm subcrestal implants (3.3 x 8 mm) using bone grafts (SCTG), 2.0 mm subcrestal implants without bone grafts (SCCG), equicrestal implants (3.3 x 10 mm) with bone grafts (ECTG) and equicrestal implants without bone grafts (ECCG). One week following the surgical procedures, metallic prostheses were installed and within 12 weeks the dogs were sacrificed. The blocks containing the individual implants were turned sideways and radiographic imaging was obtained to analyze the remodeling of the buccal bone plate. In the analysis of the resulting distance between the implant shoulder and the bone crest (IS-BC), statistically significant differences were found in the SBTG when compared to the ECTG (p=0.02) and ECCG (p=0.03). For meanvalue comparison of the resulting linear distance between the implant surface and the buccal plate (GAP-L) no statistically significant difference was found between all the groups (p>0.05). The same result was observed in the parameter for presence or absence of tissue formation between the implant surface and buccal plate (GAPA). Equicrestally placed implants, in this methodology, presented little or no loss of the buccal bone. The subcrestally positioned implants presented loss of buccal bone, even though synthetic bone graft was used. The buccal bone, however, was always coronal to the implant shoulder.

Made available in DSpace on 2014-06-11T19:30:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-07-02Bitstream added on 2014-06-13T19:40:33Z : No. of bitstreams: 1 monteiro_asf_dr_sjc.pdf: 1275364 bytes, checksum: bfdaa8d7f731a5d896cca9e24553ed29 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O propósito deste trabalho foi avaliar o efeito do plasma rico em plaquetas associados ou não ao enxerto ósseo autógeno no processo de reparação óssea em defeitos cirúrgicos confeccionados na tíbia de coelhos. Nesta pesquisa foram utilizados 25 coelhos adultos, nos quais foram realizados 2 defeitos em cada tíbia, divididos nos seguintes grupos de acordo com o tratamento: controle (C - defeito preenchido somente por coágulo sangüíneo), autógeno (A - defeito + enxerto), PRP (PRP = defeito + PRP) e autógeno + PRP (PRPA - defeito + enxerto + PRP). Todos os defeitos foram recobertos com uma barreira de PTFE e decorridos 15, 30 e 60 dias, 5 animais foram sacrificados por período, sendo as peças contendo os defeitos processadas para análises histológica e histomorfométrica. Outros 5 animais foram sacrificados aos 30 e 60 dias e submetidos à análise das propriedades biomecânicas e todos os espécimes foram submetidos ao exame radiográfico para análise da densidade óptica. Os resultados biomecânicos, radiográficos e histomorfométricos mostraram maior resistência, densidade óptica e maior formação óssea nos grupos A e PRPA quando comparados com os grupos C e PRP. Os resultados obtidos possibilitaram concluir que não houve uma melhora nos parâmetros radiográficos, mecânicos e na neoformação óssea quando o PRP foi usado isoladamente ou associado ao enxerto ósseo autógeno. / The aim of this study was to evaluate the effect of platelet rich plasma associated or not to autogenous bone graft in bone repair process of tibia rabbits surgical defects. In this research 25 adult rabbits were used, 2 defects were accomplished in each tibia, divided into groups: control (C = bone defect only filled out by blood coagulum), autogenous (A = bone defect + autogenous graft), PRP (PRP = bone defect + PRP) and autogenous + PRP (PRPA = bone defect + autogenous graft + PRP). All of the defects were covered with a PTFE barrier and after 15, 30 and 60 days there were elapsed. Five animals were sacrificed by period, being the pieces containing the defects processed for histological and histomorphometric analysis. Other 5 animals were sacrificed to the 30 and 60 days and submitted to biomechanics analysis and all of the specimens were submitted to the radiographic examination of the optical density. The biomechanic, radiographic and histomorphometric results showed larger resistance, optical density and better bone formation in the groups A and PRPA when compared with the groups C and PRP. This study demonstrated that there was not an improvement in the radiographic, mechanics, and bone formation parameters when PRP was used separately or associated to the autogenous bone graft.

Recentes estudos em animais tem demonstrado pronunciada reabsorção da tábua óssea vestibular, após a colocação de implantes imediatos. A realização de cirurgias sem retalho para a colocação de implantes imediatos, e a utilização de enxertos ósseos nos gaps, representam alternativas viáveis para minimizar a reabsorção da tábua óssea vestibular e, dessa forma, otimizar a osseointegração. O presente trabalho se propôs a investigar a remodelação da tábua óssea vestibular, associada ou não ao enxerto ósseo sintético no gap entre a superfície do implante e a tábua vestibular, em cirurgias sem retalho. Neste contexto, implantes posicionados ao nível da tábua óssea vestibular, e 2.0 mm subcrestal foram comparados. Metodologicamente, os pré-molares mandibulares bilaterais de 8 cães foram extraídos sem retalho, 4 implantes foram instalados nos alvéolos de cada lado, e posicionados 2.0 mm da tábua óssea vestibular originando o gap. Os seguintes grupos foram testados: implantes equicrestal associado com o enxerto ósseo sintético (grupo teste equicrestal-GTEC), implantes equicrestal com coágulo sanguíneo (grupo controle-GCEC), implantes 2.0 mm subcrestal associado com o enxerto ósseo sintético (grupo teste subcrestal-GTSC) e implantes 2.0 mm subcrestal com coágulo sanguíneo (grupo controle-GCSC). Uma semana após as cirurgias, próteses metálicas foram instaladas. Marcadores ósseos foram administrados 1, 2, 4 e 12 semanas após as cirurgias para a análise da fluorescência. Doze semanas após a colocação dos implantes os animais foram sacrificados. Para a análise radiográfica, cortes vestíbulo-linguais foram realizados nos blocos com os implantes individualizados, e imagens digitais radiográficas foram obtidas. Para a análise histomorfométrica, lâminas foram preparadas através dos blocos seccionados. A análise radiográfica revelou que o grupo teste subcrestal apresentou maior perda da tábua óssea vestibular com diferença estatisticamente significante quando comparado com os grupos equicrestais (p<0,05). Não foi observada diferença significativa entre os grupos em relação à distância linear, e a presença ou ausência de neoformação tecidual no gap residual. A avaliação histomorfométrica demonstrou resultados significativos para o grupo teste equicrestal, sem perda da tábua óssea vestibular. Em relação aos outros parâmetros, o grupo controle subcrestal apresentou melhores resultados. A nova formação de tecido ósseo foi determinada pela quantificação da fluorescência dos marcadores em áreas adjacentes e distantes às superfícies dos implantes. As áreas adjacentes mostraram diferentes resultados entre os grupos, e pequeno um decréscimo na 12a semana, exceto para o grupo controle subcrestal, que apresentou um aumento. As áreas distantes mostraram um aumento contínuo na formação óssea. Os implantes equicrestais apresentaram insignificativa perda da tábua óssea vestibular. No entanto, os implantes subcrestais mostraram maior perda da tábua óssea vestibular, mesmo com a presença do enxerto ósseo. No entanto, a tábua vestibular manteve-se sempre coronal ao ombro do implante. Ambos os grupos equicrestais e subcrestais testes e controles foram beneficiados nas fases iniciais do processo de formação óssea como evidenciado pela análise de fluorescência. / Recent studies in animals have shown pronounced resorption of the buccal bone plate after immediate implantation. The use of flapless surgical procedures prior to the installation of immediate implants, as well as the use of synthetic bone graft in the gaps represent viable alternatives to minimize buccal bone resorption and to favor osseointegration. The aim of this study was to evaluate the healing of the buccal bone plate following immediate implantation using the flapless approach, and compare this process with sites in which a synthetic bone graft was or was not inserted into the gap between the implant and the buccal bone plate. Lower bicuspids from 8 dogs were bilaterally extracted without the use of flaps and 4 implants were installed in the alveoli in each side of the mandible and were positioned 2.0 mm from the buccal bone plate (gap). Four groups were devised: 2.0 mm subcrestal implants (3.3 x 8 mm) using bone grafts (SCTG), 2.0 mm subcrestal implants without bone grafts (SCCG), equicrestal implants (3.3 x 10 mm) with bone grafts (ECTG) and equicrestal implants without bone grafts (ECCG). One week following the surgical procedures, metallic prostheses were installed and within 12 weeks the dogs were sacrificed. The blocks containing the individual implants were turned sideways and radiographic imaging was obtained to analyze the remodeling of the buccal bone plate. In the analysis of the resulting distance between the implant shoulder and the bone crest (IS-BC), statistically significant differences were found in the SBTG when compared to the ECTG (p=0.02) and ECCG (p=0.03). For meanvalue comparison of the resulting linear distance between the implant surface and the buccal plate (GAP-L) no statistically significant difference was found between all the groups (p>0.05). The same result was observed in the parameter for presence or absence of tissue formation between the implant surface and buccal plate (GAPA). Equicrestally placed implants, in this methodology, presented little or no loss of the buccal bone. The subcrestally positioned implants presented loss of buccal bone, even though synthetic bone graft was used. The buccal bone, however, was always coronal to the implant shoulder.

Bone grafts and titanium implants are commonly used for surgical/prosthetic rehabilitation of the atrophic edentulous maxilla. The factors which influence bone graft healing and implant integration are not sufficiently understood. The aim of this dissertation was to evaluate autogenous bone grafting and delayed placement of titanium endosteal implants for reconstruction of the atrophic maxilla, including the effects of different patient factors on bone graft healing and integration of titanium implants into grafted bone. A total of 46 patients with severe maxillary atrophy received onlay- (n=35) or interpositional bone grafts (n=11) and 6 mo. later received 341 titanium endosteal implants. All bone grafts were harvested from the iliac crest. All patients received fixed dental bridges and were followed clinically and with radiographical examinations for 3 yr. In Papers I and II, a total of 68 titanium microimplants were placed and retrieved from the bone grafts at various time points for histological analysis of the bone graft-implant interface. Integration was better after 6 mo. healing than placement in conjunction with bone grafting. Implant integration was similar for the two bone-grafting techniques. In Papers III and IV, originally including 29 patients and 222 implants, implant stability was measured with resonance frequency analysis (RFA) at placement, abutment connection, after 6 mo. of loading (III) and after 3 yr. of loading (IV). Ten non-grafted patients measured at the same time points were used as controls (III). RFA showed equal implant stability in grafted bone vs. non-grafted bone (III). Stability did not change from the 6-mo. to the 3-yr. control. Cumulative survival was 90% after 3 yr. (21 implants failed). Thirteen implants were lost prior to loading and 8 during functional loading. The group of failed implants showed a lower primary RFA stability than those that remained stable for 3 yr. All patients received and maintained a fixed dental bridge throughout the study. In Paper V, the graft volume changes (GVC) during the 6-mo. healing period prior to implant placement were studied in 30 patients using computerized tomography. Blood samples were taken from 25 patients in conjunction with bone grafting and were analysed for 13 haematological factors. Bone mineral density (BMD) was measured in 21 patients. Biopsies of the bone grafts were analysed for bone volume fraction (BVF). GVC (loss) was correlated with decreased BMD of the lumbar vertebrae L2-L4. There was no correlation between the haematological factors and GVC. Implant failure was not correlated with BMD, BVF or GVC. This dissertation shows that surgical/prosthetic rehabilitation of the atrophic edentulous maxilla with autogenous iliac crest bone grafts and delayed placement of titanium implants after 6 mo. of graft healing is effective, reproducible and functional. RFA at placement may be able to predict later implant failure.

Pathological processes in the alveolar and facial bones can lead to bone loss that may not heal with complete regeneration. Biomaterials can be used to facilitate the healing process and/or as a bone substitute, but the mechanisms are not fully understood. Persistent leakage of bacteria/bacterial toxins, after root canal treatment, may lead to a residual bone defect. The healing is dependent on a placed dental biomaterial providing a tight seal. The composition of the filling material may also influence the healing process. The general aim of this study is to investigate surface properties and biological interactions of biomaterials used in dento-alveolar surgery. A dental biomaterial, a bonded compomer (DAP) containing a corroding glass filler, was used as a root end filling material, promoting a new operation technique. The healing (assessed according to Molven´s x-ray criteria) demonstrates a significant improvement in healing results for the compomer group, compared to a commonly used technique. The surface properties and biological interactions of DAP were analyzed. ICP-OES of DAP cell culture medium extract demonstrated a significant release of Sr, Si and F from the dental biomaterial. Human periodontal ligament (PDL) cells grew on and around DAP specimens without any sign of toxic reactions. DAP extract stimulated proliferation of PDL cells, but caused an inhibition of osteoblastic gene expression in mouse bone marrow cells. The surface properties of the glass containing compomer may contribute to improved healing of the periapical lesions. A bovine inorganic bone graft substitute (BO) is commonly used as a treatment option in dento-alveolar surgery with new bone formation in immediate close contact with BO material. ICP-OES dissolution analysis of cell culture media, after incubation with BO particles, demonstrated a dosedependent release of Si and a decrease of Ca and P. An uptake of Ca from the medium to the BO particle was demonstrated with calcium-45 labeling. The Si dissolution varied between different batches, possibly reflecting a variation in food intake in the animals. Stimulated osteogenic response was seen in close contact to the BO particles in cell cultures. Furthermore, it was clearly demonstrated that the study design is a critical factor for correctly understanding biomaterials’ biological interactions. The surface properties of three bone graft substitutes reported to have good results in dento-alveolar surgery were investigated, in order to establish whether or not dissolution-precipitation reactions could contribute to the bone healing. Dissolution-precipitation extracts of BO, bioactive glass 45S5 (BG) and a marine algae hydroxyl apatite (AP) in cell culture media were analyzed. Dissolution of Si at significant levels was detected for BO and 45S5 over time. Significant uptake levels of Ca and P from the culture were seen for both 45S5, BO and AP but at different times. Surface analysis of the biomaterials with SEM/EDAX, before and after immersion in cell culture media, revealed a smoothing of the surface morphology for 45S5 over time. No obvious alterations for BO and AP were detected. Ca/P ratio decreased significantly for 45S5, but no major changes were detected by XPS for BO or AP. XPS further demonstrated a surface charge for BO, changing from negatively to positively charged when exposed to serum. 45S5 and AP had positive surface charges, both in the absence and the presence of serum. These demonstrated surface changes in biomaterials could contribute to adherence of cells and subsequently affect bone healing. Conclusion: Biomaterials used in dento-alveolar surgery interact with biological surroundings through surface and dissolution-precipitation reactions which may have implications for bone healing.

The most common cause for revision total hip replacement surgey is aseptic loosening of the acetabular component. This thesis explores the effect of three techniques to improve the depth and quality of cemented acetabular component fixation in primary total hip replacement. This may have beneficial effects on the longevity of cemented acetabular components and reduce the rate of revision surgery for aseptic loosening. Aims: 1. Determine the effect of the rim cutter on cement pressure during cup insertion. 2. Examine the effect of the rim cutter on cement penetration distance. 3. Evaluate the effect of bone grafting of the acetabular notch. 4. Determine the effect of iliac suction during cement pressurisation. 5. Compare the behaviour of bone cement with Play Dough. Materials and Methods: 1. Sawbones hemi pelvis models were fitted with pressure transducers at the rim and apex of the acetabulum. Peak pressure was measured upon insertion of cups with different flange sizes and when the acetabulum was prepared with the rim cutter. 2. Foam cavities were used to measure the depth of cement penetration when the same cups and rim cutter were used. 3. Hemi pelvis models were modified to simulate bone grafting of the acetabular notch. Again, pressure sensors were mounted at the apex and rim of the acetabulum. Intra-acetabular cement pressure was compared with native acetabulae. 4. A back bleeding model of the acetabulum was fitted with a suction catheter. The effect on cement penetration into cancellous bone was measured compared with no suction. 5. Play Dough pressurisation and penetration into hemi pelvises and foam was compared to bone cement. Results: 1. Significant increase in peak apex and rim pressures when flanged cup inserted into an acetabulum prepared with the rim cutter compared with both flanged and unflanged cups alone. 2. Significant increase in cement penetration at the rim of the acetabulum when rim cutter used and flanged cup inserted when compared with flanged and unflanged cups alone. 3. Significant increase in intra-acetabular pressure when cement pressurised in presence of simulated acetabular notch bone grafting compared with normal acetabulae. 4. Significant increase in cement penetration distance when suction used compared with no suction. 5. Significant differences in the flow characteristics between bone cement and Play Dough. Conclusion: The authors recommend preparation of the acetabular rim with the rim cutter and bone grafting of the acetabular notch to improve the depth and uniformity of the cement mantle in cemented primary THA. Play Dough at room temperature is not a suitable substitute for bone cement in in-vitro cementing studies.