Validation of the relative quantity of biochemical bond strength. Difference between interfacial bond strengths, ΔBS=BSt–BSc, always shows a positive value with statistically high significance (p=0.005). The relative quantity of the biochemical bond strength, ΔCBt–c≈(BSt–BSc), shows a mean value of 0.04 MPa. BSt and BSc are the bond strengths of the test (circles, MgPIII) and control (squares, OPIII) implants, respectively. The individual values of ΔCBt–c, BSt and BSc are shown in table 2 in the electronic supplementary material.