My photos disappeared!

I retrieved some photos from my trash folder in iPhoto and they were appearing for a split second when I would scroll and then went to the square dotted line. When I click on it it brings up the triangle exclamation symbol. I restored them to the original album and now they don't appear at all other than the square dotted line. They sat in the trash folder for probably two years. I tried restoring and rebuilding the database already and that didn't help... Any other suggestions?