How to disable access to a node
Easy! When a new Page is created, just change its owner to a different user with appropriate role and permissions. In our case, let's say to admin.

First, install the Rules package, enable Rules and Rules Admin modules.

Navigate yourself to the Rules | Triggered rules | Add a new rule page:

Label: Detach page from creator
Event: After saving new content

Make sure the new rule is active. Save changes and on the next page Add a condition:

Select the condition to add: Content has type
Content types: Page

Save and Add an action:

Select an action to add: Load a user account
User id: 1

Save and again, Add an action:

Select an action to add: Set the content author
User, who is set as author: Loaded user

Done! This changes the node creator and the original author has control over it no more.

As you will see, this is just the quickest solution to your problem. Rules module enables you to go wild and achieve heaps of stuff that you would normally expect separate modules to be put together for. To get the idea, have a look at how I used Rules (in conjunction with Flag) to keep track of Recently viewed nodes in Drupal.

Note that the node creator always has view permission to the node, as long as they have access content, without which CMS wouldn't make much sense. Anyway, to keep track of the original creator, for display or so, you can use the CCK's User reference module.