Question: I think the question title says it all:

Given a distribution board in the house (220 VAC), is it enough to shut off only the room's fuses, or must one shut off the main switch for the board before safely touching wires? 

Does the answer depend in any way on the fuse type?

Answer: 
And here is why you check it before hand, even though you have turned off that room. People get into Junction boxes and re-wire - joining two separate circuits into one - in that case one circuit in the house can be fed from two breakers (as long as they are on the same phase). Always check with testor - and NOT JUST a proximity induction testor - but an actual touch the wires testor. OK. Be safe.
Yes. Once you shut off the room fuse, no electricity will be going to that room. 

However it is important to test all connections before working on them so you are positive that they are not powered.