Surface Characterization Of Ti Implants Following Contamination With Biological Fluids And Effects Of Various Chemical Reagents On Implant Surface Contamination

"Abstract Ti-implants can get easily contaminated with saliva during surgery or after placement. This might alter its surface properties and interfere with the process of ossteointegration, ultimately leading to pre-implantitis and implant loss. Though several chemical agents are routinely used for implant decontamination, their exact effect is not well known and hence identifying their effect on Ti and oral contaminants is critical for developing better treatments for decontamination of Ti dental implants. Thesis objective manuscript-base was to characterize the physical properties of saliva-contaminated titanium surfaces and further assess the different chemicals that could be used for osteointegration. In the first manuscript, we evaluated the efficacy of 6 different solutions that are commonly used to manage peri-implantitis (Listerine, 0.2% Chlorhexidine, 50% citricacid, 0.9% saline, PBS and 35% phosphoric acid) on saliva-contaminated implant surfaces. We used x-ray photoelectron spectroscopy (XPS) to assess the elemental composition of the surfaces and fluorescence microscopy to assess the bacterial load. XPS analysis revealed that amongst all the solutions assessed, citric acid and saline were the most effective in decontaminating Ti and partially restoring the original implant surface chemistry. Although none of the solutions was able to fully recuperate the original surface chemistry. All of them except saline and Listerine were effective in reducing the microbial load. These results indicate that amongst the solutions tested, citric acid and saline could be the best option for clinical application. In second manuscript of this thesis, we assessed how saliva interacts with Ti-surfaces and the subsequent implication on Ti-blood interaction. We used contact angle measurements (CAM), x-ray photoelectron spectroscopy (XPS) and fluorescence microscopy to characterize Ti samples before and after exposure to human saliva. The effect of saliva contamination on blood-implant interaction was further investigated. Our analysis revealed that on the Ti surfaces saliva formed a bacterial-rich hydrophobic organic layer that interfered with Ti-Blood interaction. After revealing the hydrophobic nature of saliva surface contaminants, we explored the use of solvents (acetic acid and acetone) and detergents (tween20) for Ti surface decontamination. Indeed, our analysis demonstrated that acetic acid and tween-20 achieved substantial elemental as well as microbial decontamination, suggesting that they can be potentially useful for Ti-implant decontamination. This part of this study therefore demonstrates that saliva interacts with Ti-implants interfering with blood Ti interaction but this saliva contamination can be managed with the use of acetic acid and tween-20 for Ti decontamination. Therefore saliva interferes with the interaction of Ti-implants with blood by creating a hydrophobic layer that it is rich in bacteria. However this layer can be easily remove with solvents, detergents or calcium chelators." --