question with "wp-admin" directory

Hi.
I have two wordpress installations.
Now I had a issue with one of the sites and I misstakenly deleted “wp-admin” directory from one of the sites.

I resolved this issue by copying the same directory from the other site. Everything seem to be allright, at least the front end looks good.

Are there any other things I need to correct?
the two sites were not running the same version of wordpress, theme but the same database.

Thanks for all help.