There is a way ,
Office Icons – Change or Repair , but I shouldn't suggest you this one , it is too laborious
If you reinstall MS Office over the existing installation , you will get your office icons back .
Now, what is most important is to retain the icons there

. So , I'd suggest you to stop using your third party registry cleaners (like tuneup utilities) . Only one program that I can recommend you is
CCleaner - Free version . It doesnot delete the installer folder (where these icons and uninstallers are stored) like the others.