Thesis (B.Sc)--University of Hong Kong, 2007. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2007." Includes bibliographical references (p. 26-30). Also available in print.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 185-195).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves [98]-103).

Thesis (M.S.B.)--University of Toledo, 2005. / Typescript. "A thesis [submitted] as partial fulfillment of the requirements of the Master of Science degree in Bioengineering." Bibliography: leaves 73-75.

Thesis (Ph.D.)--University of Iowa, 2006. / Supervisor: J. Bruce Tomblin. Includes bibliographical references (leaves 92-99).

Thesis (M.D.S.)--University of Hong Kong, 2005.

Thesis (M. Communication Pathology)--University of Pretoria, 2006. / Summary in English and Afrikaans. Includes bibliographical references.

No description available.

The most common type of adverse events in healthcare in Canada reported by the Canadian Institute for Health Information (CIHI) are nosocomial infections. Amongst nosocomial infections, implant associated infections have been reported to be most common. Despite having the implantation surgeries carefully performed, a small, but still considerable number of devices gets colonized by bacteria resulting in implant associated infections and/or surgical site infections. The patients are then started on high dose antibiotics, which if ineffective, is followed by reimplantation surgeries that leads to long hospital stays and detrimental effects in their lives. Due to this, an alternative to antibiotics is required which could prevent and/or treat bacterial colonization on implants. The main objective of this thesis was to demonstrate the effectiveness of an antimicrobial based CLKRS peptide capped silver nanoparticle coating on a metallic and polymeric based biomaterial used in various implantable medical devices. The CLKRS peptide capped silver nanoparticle formulation was specifically engineered and tested for its antibacterial and antibiofilm properties. Silver nanoparticles were synthesised by photochemical reduction of silver ions upon photocleavage of the photoinitiator I-2959. The metal nanostructure surfaces were protected with the CLKRS peptide and tested on planktonic and biofilms of P. aeruginosa, S. aureus and S. epidermidis. The bacterial quantification was done by survival colony counting. The cytotoxicity of the silver nanoparticle formulation was also tested on human dermal fibroblast, mouse bone marrow derived macrophages, and human epithelial cells by cell proliferation assay. Results show the formation of a nanometric layer of nanosilver on the surface of the material inhibiting the growth of bacteria and eradicating pre-existing biofilms with no significant cell toxicity suggesting the prepared formulation could be a useful tool in preventing and controlling infections on implants during surgery and post implantation. This technology thus could serve as an alternative therapy for surgical site infections and/or implant associated infections.

Orientador: Eduardo Passos Rocha / Banca: Wirley Gonçalves Assunção / Banca: Idelmo Rangel Garcia Júnior / Banca: Paulo Guilherme Coelho / Banca: Paulo Francisco César / Resumo: Proposição. O objetivo do presente trabalho foi avaliar a influência do conceito de plataforma switching na confiabilidade e modo de falha de restaurações unitárias sobre implante com hexágono externo ou interno na região anterior da maxila. Adicionalmente, análises de elementos finitos foram realizadas para avaliar o padrão de distribuição de tensão dentro do complexo pilar-implante e no tecido ósseo peri-implantar. Materiais e Métodos. 84 implantes foram divididos em 4 grupos (n = 21) para realização dos testes de fadiga: SWT-EH e REG-EH (implantes de conexão externa com plataforma switching ou regular, respectivamente); SWT-IH e REG-IH (implantes de conexão interna com plataforma switching ou regular, respectivamente). Análises estatísticas de Weibull foram realizadas considerando as missões de 50.000 ciclos a 210N e 300N. Adicionalmente, foram construídos 4 modelos de elementos finitos considerando as mesmas variáveis para obtenção das tensões equivalentes de von Mises (σvM) no complexo pilar-implante e das máximas tensões principais (σmax) no osso peri-implantar. Resultados. Os valores de Beta para os grupos SWT-EH (1,31), REG-EH (1,55), SWT-IH (1,83) e REG-IH (1,82) indicaram que a fadiga acelerou a falha em todos os grupos. Os valores de confiabilidade calculados para os grupos SWT-EH, REG-EH, SWT-IH e REH-IH foram 0,53 (0,33 - 0,70), 0,93 (0,80 - 0,97), 0,99 (0,93 - 0,99) and 0,99 (0,99 -de tensão estiveram no pilar (SWT-IH = 186 MPa e REG-IH = 88.8 MPa). No osso cortical, os implantes com plataforma switching geraram menor tensão (σmax) tanto para conexão externa (SWT-EH = 49.0 MPa e REG-EH = 56.5 MPa) como para conexão interna (SWT-IH = 37.7 MPa e REG-IH = 45.5 MPa)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Purpose. The aim of the present study was to evaluate the effect of platform switching concept on reliability and failure modes of anterior single-unit restorations for internal and external hex implants. Additionally, finite element analysis were performed to assess the stress distribution within implant-abutment complex and peri-implant bone. Materials and Methods. 84 implants were divided in 4 groups (n=21) for fatigue tests: REG-EH and SWT-EH (regular and switched-platform implants with external connection, respectively); REG-IH and SWT-IH (regular and switched-platform implants with internal connection, respectively). Weibull analysis for a mission of 50,000 cycles at 300N was performed. Additionally, 4 three-dimensional finite element models reproducing the characteristics of specimens used in mechanical tests were created to evaluate the equivalent von Mises stress (σvM) within implant-abutment complex and the maximum principal stress (σmax) in the peri-implant bone. Results. The Beta values for groups SWT-EH (1.31), REG-EH (1.55), SWT-IH (1.83) and REG-IH (1.82) indicated that fatigue accelerated the failure of all groups. The calculated reliability for groups SWT-EH, REG-EH, SWT-IH and REH-IH were 0.53(0.33-0.70), 0.93(0.80-0.97), 0.99(0.93-0.99) and 0.99(0.99-1.00), respectively. Failure modes (screw and/or abutment fracture) were similar for regular and switched-platform implants. Within implant-abutment complex, the higher peak of stress (σvM) was observed in fixation screw (SWT-EH = 190 MPa and REG-EH = 160 MPa) for groups with external hex implants; while for groups with internal hex implants was in abutment (SWT-IH = 186 MPa and REG-IH = 88.8 MPa). In the cortical bone... (Complete abstract click electronic access below) / Doutor