Statement of Purpose: Periprosthetic joint infection (PJI) is a devastating complication of total joint arthroplasty. In addition to being extremely difficult to treat with antibiotics alone, PJI is also difficult to detect . These problems stem from the ability of bacteria to form biofilms on the surface of implanted materials. When in the biofilm state, bacteria gain a diffusional barrier which limits the penetration of antibiotics, and causes a reduction in the metabolic activity of the resident cells. This can make detecting biofilms with traditional culture methods difficult. For this reason, new methods for the detection of biofilms on implanted orthopedic materials are needed. This work evaluated the electrochemical methods of potentiometry and electrochemical impedance spectroscopy (EIS) as diagnostic measures of bacterial biofilm formation on titanium in an in vitro model. Methods: A custom designed polycarbonate electrochemical biofilm reactor (Fig 1) was utilized to both grow biofilms and make the electrochemical measurements.