Indeed they do. With virtually every country if you compare their violent crime and homicide rates both before and after a gun ban the rates sky rocket for many years after and never return to normal.
So yes there are more people dying as a result of their gun laws and that can be seen across most nations that have had gun bans and inferred to be the same effect in the netherlands.
Most of the data for this i have is for other countroes like england, ireland, jamaica, but sadly limited data on the netherlands on hand.