Random question mark symbols throughout posts

After trying to upgrade to WordPress 3.5, all our Pages converted to Pages. So we did a restore and it lost all of our formatting. Now we’re left with random questions marks (�) throughout all of our posts.

Is there any way to get rid of the � without having to go into hundreds of posts and correct it one at a time?

The � do not always replace an apostrophe – sometimes it is simply between words.

See example here: http://highlineonline.ca/2011/12/23/the-sound-of-silence/

…or on any of our posts.