The paper deals with biomaterial electromagnetic non-destructive testing with an emphasis on real defects identification. Various modifications of eddy current testing (ECT) detection sensors will be compared and discussed from the desired detected signal characteristics points of view. Advanced magnetic sensors such as giant magneto-resistance (GMR) sensors and fluxgate sensors and probe coils are presented in the paper. These advanced sensors are characterized by their sensitivity, frequency range and sensors dimensions. The measurements for detection of stress corrosion cracks (SCC) in implants materials using magnetic sensors will be presented and their responses will be compared.