Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Dental Materials

1.Implant-associated infections are one of the most serious complications in orthopedic surgery and a major cause of implant failure. Establishing antibacterial surface at titanium implant surface is crucial for osseointegration and long-term success of the implants. Therefore, various surface modifications have been developed to Ti-6Al-4V implants in an attempt to prevent bacterial colonization and prevent the implant loss. So, coating the titanium dental implant with chitosan biologically active molecule has been applied with using electrophoresis technology. 2.In this study, electrophoretic deposition of chitosan and hybrid chitosan/HA composite structures coatings was employed to prepare antibacterial titanium dental implant surfaces. Two hundred and twenty Ti-6Al-4V discs were divided equally into five groups to receive different surface coating. Group 1; Native (untreated) implant discs "control group". Group 2; discs coated with chitosan biologically active molecule.Group3; discs coated with calcium phosphate intermediate layer act as carrier. Group 4; for composite structure, discs coated with chitosan/calcium phosphate with the lower current density (I=1.5mA/cm2). Group 5; discs coated with chitosan/calcium phosphate with higher current density (I=2mA/cm2). The different coated Ti-alloy discs were characterized by XRD, FTIR, ESEM and SEM. Coat weight of different deposited surfaces were assessed by sensitive balance. The quantities of chitosan deposited on Ti-alloy were monitored by chitosan indicative FTIR bands. The release rate of chitosan was monitored by quantitative analysis of the chitosan characteristics functional groups and the amount of weight loss at different time intervals; 48, 96,192 and 384 hrs. Antibacterial activity of activated chitosan and composite hybrid chitosan coating was assessed against two bacterial strains; S. aureus and E. coli by using Colony forming units' plate counting method (CFU)

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