Wordpress restrict user in back-end to certain pages

In my current Wordpress plugin i have create an admin page where there are two select options. First one is to select a user and second one for wp_dropdown_pages. When i select a specific registered user of my site and a page from dropdown than save the option. When the specific user login to back-end he can access only the page that i have selected from my admin menu page. I can restrict that user from other menu page using remove_menu_page( $menu_slug ). Now i want that user only to access page that i have selected for him. Other pages will be disappeared/access denied from admin All pages menu. How can i do that? Thanks in advance.