I had lost two molars, one on each side, years ago and my dentist at the time put a spacer in. Ten years later it breaks. My new dentist try to re-cement but it did not work. Now I have a Essix retainer. I find it very cumbersome and uncomfortable, but will use it until I can afford implants. Is it okay to wear the retainer only at night or should I wear it all the time as my dentist said?