Methods for improving the antibacterial characteristics of biomedical implants and related implants manufactured according to such methods. In some implementations, a biomedical implant comprising a silicon nitride ceramic material may be subjected to a surface roughening treatment so as to increase a surface roughness of at least a portion of the biomedical implant to a roughness profile having an arithmetic average of at least about 500 nm Ra. In some implementations, a coating may be applied to a biomedical implant. Such a coating may comprise a silicon nitride ceramic material, and may be applied instead of, or in addition to, the surface roughening treatment process.