| Just to clear some confusion. With NGK the plugs the -9 indicates that the plug is pre-gapped to .9mm i.e. 35 thou.
The C in DCPR means it has a copper core
and the A in DPR8EA-9 means it has a "Special electrode" whatever that is.
IX means an Iridium centre electrode
So a DCPR8E is the same plug as a DPR8EA-9 but with a wider heat range due to the copper core and it has a standard gap of, I think, 0.6mm and something different about the electrode.
The IX versions are the same plugs with an iridium electrode.
So a DCPR8E or DCPR8EIX should be a suitable replacement for a DPR8EA-9 or DCPR8EIX-9 apart from the gap which you can increase if you wish.
Ducati recommends 0.6mm but the igntion system is quite capable of firing the 0.9mm gap which reduces the chance of plug fouling.
I think NGK have just updated their plug refernces to reflect the improved performance of their newer technologies. | 
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