Surface roughness (Ra), micrometre, of PEEK-OPTIMA and cobalt chrome plates taken perpendicular to the direction of scratching (A) pre- and post- wear simulation, data relates to Table 3.				
				
CONTROL TEST				
				
	0um	1um	2um	4um
Pre test				
CoCr 1	0.004	0.005	0.004	0.005
CoCr 2	0.003	0.004	0.004	0.004
CoCr 3	0.004	0.004	0.003	0.004
CoCr 4	0.004		0.005	0.004
PEEK 1	0.020	0.025	0.025	0.026
PEEK 2	0.017	0.031	0.029	0.030
PEEK 3	0.017	0.034	0.027	0.027
PEEK 4	0.022		0.019	0.018
				
				
Post wear test				
CoCr 1	0.051	0.007	0.017	0.006
CoCr 2	0.031	0.010	0.007	0.004
CoCr 3	0.021	0.009	0.018	0.038
CoCr 4	0.005		0.032	0.027
PEEK 1	0.632	0.720	0.523	0.359
PEEK 2	0.321	0.866	0.238	0.921
PEEK 3	0.631	0.603	0.709	1.076
PEEK 4	0.577		0.994	1.001