When you field strip the pistol you'll see the left side slide stop is supported by a section of metal inside the frame. That's why it doesn't wobble even without the right side slide release.
I'm not sure of the age of your pistol, vs. mine (I have a Pre B CZ 85) but the newer right side slide release won't fit into the hole in the frame. Seems they made the right side slide release shaft larger due to a breaking issue with the Pre B version. If your pistol can use the later version of the right side slide release you can order a replacement. The guys at CZ Custom may be able to help you with that if you give them a call (help meaning tell you whether or not the newer piece would work based on the year your pistol was made.
If your pistol uses the older version of the right side slide release then one option is to have the frame/hole opened up by a gunsmith so that you could use the right side larger sized slide release.
There is a spring, inside the frame, that holds both sides of the slide release in the frame once installed.
This is actually a CZ 75 Compact I converted to use CZ 85 type controls. But you can see the piece of frame, inside, that supports the left side slide release (on the right side in this picture) and the small spring just to the left of it that holds both sides of the slide release in place in the frame.
Edited to add the original picture, but from imgur now that photobucket stabbed us in the back. First opportunity to fix one.
I actually really like the dual controls. I have the Pre B CZ 85 and the converted CZ 75 Compact and carry the compact on a regular basis.