Le maintien des tissus péri-implantaires sains à un niveau le plus coronaire possible conditionne le succès à long terme des réhabilitations implanto-portées. Dès lors, la mise en place d'une barrière muqueuse protectrice et la préservation de l'os marginal au cours des premières semaines de cicatrisation est indispensable. Le design implantaire influence les remodelages tissulaires intervenant au niveau du col de l'implant lors des phases initiales de cicatrisation. L'objet de ce travail est d'analyser histologiquement chez le Beagle l'influence de deux systèmes implantaires innovants sur les caractéristiques de la muqueuse et la position de l'os marginal après 3 et 12 semaines de cicatrisation. Les résultats de cette étude, mis en relation avec les données de la littérature indiquent que les implants « deux-parts » présentant une connectique cône morse pourraient favoriser la mise en place d'un espace biologique court et limiter la perte osseuse marginale péri-implantaire. Les implants « une part » à col transmuqueux concave seraient quant à eux associés à des valeurs réduites d'espace biologique et autoriseraient une apposition osseuse sur l'épaule de l'implant. Dans la première partie de ce mémoire, nous établissons une synthèse des données histologiques actuelles concernant les caractéristiques et les processus de cicatrisation des tissus péri-implantaires, et l'influence de la conception implantaire sur les remodelages tissulaires marginaux intervenant au cours de la cicatrisation. Nous avons rédigé deux publications internationales que nous présentons en deuxième partie. Une réflexion analytique autour de ce travail est présentée dans la troisième partie / Aesthetic and functional long-term success of implant-supported rehabilitations relies on the preservation of peri-implant tissue levels in the most coronal position. Therefore, the achievement of an efficient protective mucosal seal, and the preservation of the peri-implant marginal bone during the first weeks of healing are essential to prevent long term implant failures. The characteristics of an implant transmucosal design (connections, platforms, surface properties) are related to biological width dimensions, marginal peri-implant bone levels, and the amount of inflammation within the peri-implant soft tissues. The aim of the research work presented in this manuscript was to investigate the effect of two innovative implant systems on peri-implant mucosa maturation, dimensions, collagen fiber organization, and marginal bone levels after 3 and 12 weeks of healing in the beagle dog. The results, compared with previous data, show that platform-switched twopiece implants exhibit reduced values of biological width and marginal bone loss, and that a concave transmucosal design in one-piece implants is associated with a short vertical value of biological width, and promote a mechanical interlocking of the implant body at the connective tissue and marginal bone levels. In the first part of this report, an overview of the current knowledge concerning the characteristics and healing patterns of peri-implant tissues, and the influence of implant design on the early peri-implant tissue remodeling is established. We have written two international publications which are presented in the second part. An analytical reflection about this work is presented in the third part

Resumo: O objetivo do presente trabalho de pesquisa foi avaliar a influencia do tipo de conexao protetica, do platform-switching, e do design do implante no ambiente biomec.nico de implantes imediatos com carga imediata. Para tanto, um modelo de alveolo de extraçao de um incisivo central superior foi constru.do baseado em tomografia computadorizada. Implantes inseridos no alveolo de extra..o foram avaliados por meio de analises em elementos finitos. Uma Analise de Variancia (α=0.05) foi utilizada para interpretar os dados do pico de deformaçao equivalente no osso, do pico de tens.es equivalentes no parafuso do abutment, do deslocamento relativo osso-implante e do gap do abutment. A maior influ.ncia do tipo de conexao protetica e do platform-switching foi observado na tensao do parafuso e no gap do abutment. Por sua vez, o design do implante afetou consideravelmente as deformaçoes no osso e o deslocamento relativo entre o osso e o implante. Nao obstante, evitar a sobrecarga do implante e garantir uma alta estabilidade inicial sao os fatores mais importantes na previsibilidade de implantes imediatos com carga imediata / Abstract: The aim of the present research work was to evaluate the influence of different connection type, platform switching and implant designs on the biomechanical environment of immediately placed implants. A CT-based model of an upper central incisor extraction socket was constructed. The immediately placed implants were evaluated by finite element analysis. An Analysis of Variance was used to interpret the data for the peak equivalent strain in the bone, peak Von Mises stress in the abutment screw, bone-to-implant relative displacement and abutment gap. The largest influence of the connection type and platformswitching was seen on the peak equivalent stress in the abutment screw and implant-abutment gap. On contrary, the implant design considerably affects the biomechanical environment of immediately placed implants. However, avoiding implant overloading and ensuring a high implant initial stability are the most important factors for the predictability of implants in this protocol / Orientador: Luis Geraldo Vaz / Coorientador: Elcio Marcantonio Junior / Coorientador: Sonia Aparecia Goulart de Oliveira / Banca: José Maurício dos Santos Reis Nunes / Banca: Rogério Margonar / Banca: Pedro Yoshito Noritomi / Banca: Flávio Domingues das Neves / Doutor

Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-25Bitstream added on 2014-06-13T19:43:55Z : No. of bitstreams: 1 pessoa_rs_dr_arafo.pdf: 1780565 bytes, checksum: 78498002897f7571851e27403dd44a72 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo do presente trabalho de pesquisa foi avaliar a influencia do tipo de conexao protetica, do platform-switching, e do design do implante no ambiente biomec.nico de implantes imediatos com carga imediata. Para tanto, um modelo de alveolo de extraçao de um incisivo central superior foi constru.do baseado em tomografia computadorizada. Implantes inseridos no alveolo de extra..o foram avaliados por meio de analises em elementos finitos. Uma Analise de Variancia (α=0.05) foi utilizada para interpretar os dados do pico de deformaçao equivalente no osso, do pico de tens.es equivalentes no parafuso do abutment, do deslocamento relativo osso-implante e do gap do abutment. A maior influ.ncia do tipo de conexao protetica e do platform-switching foi observado na tensao do parafuso e no gap do abutment. Por sua vez, o design do implante afetou consideravelmente as deformaçoes no osso e o deslocamento relativo entre o osso e o implante. Nao obstante, evitar a sobrecarga do implante e garantir uma alta estabilidade inicial sao os fatores mais importantes na previsibilidade de implantes imediatos com carga imediata / The aim of the present research work was to evaluate the influence of different connection type, platform switching and implant designs on the biomechanical environment of immediately placed implants. A CT-based model of an upper central incisor extraction socket was constructed. The immediately placed implants were evaluated by finite element analysis. An Analysis of Variance was used to interpret the data for the peak equivalent strain in the bone, peak Von Mises stress in the abutment screw, bone-to-implant relative displacement and abutment gap. The largest influence of the connection type and platformswitching was seen on the peak equivalent stress in the abutment screw and implant-abutment gap. On contrary, the implant design considerably affects the biomechanical environment of immediately placed implants. However, avoiding implant overloading and ensuring a high implant initial stability are the most important factors for the predictability of implants in this protocol