S.T.
I am a dental hygienist, so I see all kinds of retainers. The absolute worst kind are the kind they cement to the lingual (tongue) side of each tooth. Impossible to keep clean. Much better are the ones that they just cement to the canines and then have an arch wire that keeps your teeth in place. With these you can go in through one gap, pull the floss up over the top and move the floss behind the arch wire flossing between each tooth. They can show you how to do this at the office. Removable retainers are great, BUT, because they are removable and show quite a lot, people wear them only at night. So there is potentially 12-16 hours of time that your teeth are shifting. They don't work as well. Water piks do work great at keeping retainers clean. So in my experience, and I have seen a whole lot of retainers, is to get the arch wire kind that is cemented only on your canines.