Forbid additional object definitions of a specific type

Hello, 

i want to forbid users to create new object definitions of one specific object type, so they only can use the ones already existing. But these objects have to exist, which is why i can't forbid them in the filter. 

Is that possible? 

For example: Nobody can create new objects of type "Time planner", they only can use the already existing objects.

Thanks in advance! 

Regards, 

Richard