My dry mouth is all of the time. I can't know because I am sleep, but never heard comments of mouth open sleeping. Mouth rinses only work five min or less. Dentist is baffled! I go every six month except past two years broke a tooth I'm between and had to go back. I can't make enough saliva to keep teeth healthy. Dentist says I can see you take great care of teeth so I cannot understand why you have so many problems. Even sleep with guard to protect teeth from excess wear on right side. Just read about a flouride mix Dr can prescribe. Will ask tomorrow when I go in for repair on broken tooth. Thanks all for support and suggestions!