Well, okay maybe not the flossing part ... but it is a good idea to brush your dog daily to get him used to holding still, being brushed, examined and handled as a part of a daily routine. This is also good practice in the likelihood of your dog needing medical attention, bandaging or other treatments. If your dog is used to being handled then in an emergency situation there is not the added stress of being restrained and possible prolonged recovery.
You can even teach your dog to enjoy wearing a muzzle or a "cone" and if the need arises at some point in his life then there is no added element of stress.
or conditioning to anything for that matter! This is a great video ... watch for the dog's "Yipee response" at each step of the process.
In our STEP ONE Training Workshop we teach you the beginning steps of targeting, body handling, and how to add value so that your dog eagerly anticipates these times instead of merely tolerating, or worse, struggling and increasing their fears.
http://pawinhand.blogspot.com/p/step-one.html