In dental school interviews, I think they ask applicants to do some kind of carving out of chalk to test their manual dexterity. The quality of the final product is assigned a numeric score and factored in for admission purposes. I'm not sure if this is every dental school, but it is true of LSU, where one of my friends went. That may be what you're referring to as a "bench exam." There's nothing like this in med school interviews.