Analysis of scratches on the cobalt chrome plates after damage simulation phase using the Bruker NPFlex white light interferometer, data relating to Table 3 in the manuscript.	

This analysis was only carried out on plates damaged with third body particles so a value of N/A is shown for the positive and negative controls.  A value of 0 means there were no measurable scratches on the surface of the plate.

PGCS: Pharmaceutical grade of calcium sulfate: Stimulan (Biocomposites Ltd, Keele)
MGCS: Medical grade of calcium sulfate: Osteoset (Wright Medical Technology, TN, USA)
PMMA: SmartSet GMV Gentamicin bone cement (DePuy Synthes, IN, USA)	
														
																
mean lip height (mm) of scratches for each plate																
																
Sample	Negative control	Positive control	PGCS	MGCS	PMMA				
1	N/A	N/A	0	0.021	0.029				
2	N/A	N/A	0	0.036	0				
3	N/A	N/A	0	0.039	0.012				
4			0	0.051	0.073				
																
																
mean number of scratches per mm for each plate																
																
Sample	Negative control	Positive control	PGCS	MGCS	PMMA
1	N/A	N/A	0	2.3	0.38
2	N/A	N/A	0	1.3	0.1
3	N/A	N/A	0	0.9	0.12
4			0	1.96	0.14


mean valley depth (mm) for each plate

Sample	Negative control	Positive control	PGCS	MGCS	PMMA
1	N/A	N/A	0	0.020	0.016
2	N/A	N/A	0	0.015	0
3	N/A	N/A	0	0.011	0.007
4			0	0.020	0.044