Zirconia implants have emerged as a promising novel material in the field of dentistry due to their ability to overcome certain limitations associated with titanium implants. However, the appropriate sterilization protocols for zirconia implants have not yet been thoroughly investigated. To address this gap, this study conducted an assessment of the surface characteristics of fully sintered 3Y-TZP zirconia slices after being subjected to various sterilization methods, including ethylene oxide (EO), hydrogen peroxide plasma (HPP), electron beam (EB), and a combination of hydrogen peroxide plasma with either ethylene oxide (HPP+EO) or electron beam treatment (HPP+EB). Although the HPP treatment group did not demonstrate the highest level of hydrophilicity and contamination removal, it did exhibit notable hydrophilicity, effectively prevented hydrocarbon contamination, and maintained a substantial concentration of Zr. The surface of zirconia treated with HPP displayed significant enhancements in cell proliferation, cytoskeleton development, osteogenic differentiation, and adhesion capabilities for hBMSCs and HGFs, surpassing the performance of other groups. Based on these findings, the sterilization of zirconia implants using hydrogen peroxide plasma therapy appears to be a feasible technique.