Engineering Mechanisms Causing Adverse Biofilm Responses to 3D Printed Titanium Surfaces

ABSTRACT This project enables the future of personalized dental implants by monitoring biofilm responses to the different surface textures and chemistries produced by 3D metal additive implant manufacture. Metal additive manufacturing offers implantology the freedom to incorporate advanced configurations, half sizes for patient- specific needs, and control over near-surface properties important for osseointegration such as multi-scale texture and topography. However, implant surfaces that are exposed to the oral cavity are difficult to keep free of plaque and disease. Because bacterial biofilms are competing in this environment, specific attention is needed to understand how biofilm properties are affected by the surfaces produced from the AM process. The focus of this proposal is on improving implant design through development of a suite of experimental mechanics tools to understand biofilm response and to improve biocompatibility screening. We will provide insight into the propensity for adverse biofilm structure and adhesion on 3D printed metal implant formulations. Adverse biofilm structures are those biofilm configurations that resist deformation and have large adhesion strength (difficult removal) and resist small particle diffusion (difficult to kill by diffusing antimicrobials). We will measure the structural, deformation, and diffusive properties of single and multispecies oral biofilms on relevant and futuristic titanium implant materials. In addition to biofilm response, a numerical factor that makes the interpretation of the measurements easy to implement is needed. We will measure the Adhesion Index of additively manufactured titanium using the laser-induced spallation technique. Successful completion of this research results in new tools for quantitative deformation, diffusion, and adhesion measurement of oral biofilms on additively manufactured titanium interfaces.