The first time i had a 3 unit bridge installed, the hygienist said, "well you know how to thread it" and left me. office was busy and i confused. hmm?

Floss Threader: The hygienist was referring to a floss threader, which looks like a large sewing needle with a large loop as the eye of the needle on one end. You pass dental floss through the loop and pass the needle end under your bridge which allows you to pull the dental floss under the bridge so you can floss the teeth supporting the bridge.