Valid for Sitecore 
  5.1.1 and 5.2
Is it possible to restore items which have been moved to the archive database?
  
    Sitecore versions: Expected to work with 5.1.1.x and 5.2.0.x releases.
  Q: 
  Is it possible to restore items which have been moved to the archive database? If so, how is this done? 
  A: 
  You can do this in the following way: 
  
    - 
      Switch to the Archive database     
- 
      Open the Content Editor 
 
 
- 
      Find item(s) you want to restore 
 
 
- 
      Select “Item xml” field and copy a value to the Clipboard system     
- 
      Switch to the Master database 
 
 
- 
      Select an Item under which you want to restore item(s) form the Clipboard 
 
 
- 
      Right click on the parent Item  »Clipboard » Paste from Clipboard
  
 The Item will be restored.