Shimano Dura Ace FC7900 crankset with 11 speed group? I have a Dura ace FC7900 crankset and was wondering If I can use it on a bicycle with ultegra 11 speed group?

The crankset I have is this one:
http://www.bike-discount.de/en/buy/shimano-dura-ace-crankset-fc-7900-53-39-170mm-31545

Thanks
The FC7900 crankset is from a 10 speed group.

Nobody's going to stop you from doing this and having it work -- Zinn has done it and claims that it works. Manufacturers will will say otherwise claiming weaker FD springs or very slightly different chainring spacing. 

Since you already have the crankset, may as well put it in and try it if you want to use it.