You will need to adapt the edit templates for these specific classes. You can check who is editing, determine the group/role assigned and then display or not display the checkbox.
A good exercise in learning the template language
Alternatively, use the workflow system, it is made for that situations
If you need to have some sort of an approval mechanism then I suggest that you take a look at the approwal workflow. This is already built into eZ publish and ready for use. An example of how it can be set up is explained in the "Building an eZ publish site" tutorial:
