Mean surface roughness (Ra), micrometre, of cobalt chrome and PEEK-OPTIMA plates, pre-test, after damage simulation with PMMA cement particles and after wear simulation, data relates to Table 1.						
						
CONTROL TEST					DAMAGE SIMULATION	
	Perpendicular to damage (A)	Perpendicular to wear test (B)			Perpendicular to damage (A)	Perpendicular to wear test (B)
						
Pre test				Pre test		
CoCr 1	0.013	0.0126		CoCr 1	0.014	0.015
CoCr 2	0.013	0.0128		CoCr 2	0.004	0.004
CoCr 3	0.013	0.0135		CoCr 3	0.014	0.015
PEEK 1	0.019	0.0141		PEEK 1	0.006	0.018
PEEK 2	0.019	0.0146		PEEK 2	0.007	0.018
PEEK 3	0.020	0.0139		PEEK 3	0.006	0.018
						
Post damage simulation with particles				Post damage simulation with particles		
CoCr 1	N/A	N/A		CoCr 1	0.016	0.016
CoCr 2	N/A	N/A		CoCr 2	0.005	0.005
CoCr 3	N/A	N/A		CoCr 3	0.015	0.016
PEEK 1	N/A	N/A		PEEK 1	0.056	0.022
PEEK 2	N/A	N/A		PEEK 2	0.052	0.024
PEEK 3	N/A	N/A		PEEK 3	0.053	0.023
						
Post wear test				Post wear test		
CoCr 1	0.037	0.014		CoCr 1	0.013	0.013
CoCr 2	0.014	0.012		CoCr 2	0.006	0.014
CoCr 3	0.032	0.015		CoCr 3	0.013	0.016
PEEK 1	0.164	0.022		PEEK 1	0.018	0.172
PEEK 2	0.068	0.018		PEEK 2	0.021	0.078
PEEK 3	0.044	0.018		PEEK 3	0.014	0.044