Sure...
Try deleting the plist(s) created by the dictionary app.
youruser/Library/Preferences/com.apple.Dictionary.plist
or, same folder com.apple.DictionaryServices.plist
Then, back out to the Library, and open the Caches folder. Trash the file com.apple.Dictionary and the folder named com.apple.DictionaryApp
If Dictionary is the only app that has lost a scroll bar, that should fix it.