Many dentists have a Google+ page that is in serious need of revision or simply needs to be deleted. For example the dentist is listed as doing business at an old location where they worked as an associate. Even worse the actual owner of the practice is not listed by Google+ but the long gone associate is.
Deleting a page is permanent and cannot be undone. If you are moving or closing a location you do not want to delete the page, there are systems to keep the page content and simply move it to the new location.
Instructions for deleting a Google+ page can be found here.
Better yet go to support.google.com/business for help with getting started, setting up multiple locations or transferring ownership of a page.