Dry mouth causing tooth decay

I have been having extreme dry mouth when using my CPAP and at a recent dental check discovered 3 cavities under bridges, which dentist say is likely due to the dry mouth. I know that I sometimes breath with my mouth slightly open, but not enough to register a problem with my machine. I get 100 points most nights on my ResMed report unless I don't get the hours of sleep it is set for. The dryness wakes me sometimes. I have tried both nasal masks and full masks, and 2 different types of chin straps, none of which helps. As I said, my mouth is only slightly open, not enough for the chin strap to prevent it, and the machine seems to be doing its job. Any suggestions?

I have not had the tooth decay issues, but I use a nasal pillow mask and have issues with air escaping out of my mouth during sleep. The Breathewear Halo chin strap that I use prevents most of it, but to totally stop the mouth leaks I have gone to using 1" 3M NexCare paper medical tape. I tape across my mouth from side to side and leave it there overnight. It totally stops air leakage out of the mouth. Here is a link to a video by a dentist that talks about it.

How to Mouth Tape for a Better Sleep

Unfortunately ResMed seems to understate the mask leakage issue. I do not use MyAir, but do look at the happy faces each morning on the display. In six months I only got leaks bad enough to get the red unhappy face once. And those leaks were really really bad. To see what is really happening one needs to look at the results in SleepyHead. Here are two SleepyHead reports. One is without using mouth tape, and the second one is with mouth tape. Both were with the same nasal pillow P10 mask. In these reports the gray areas are times when the leak rate is over the leak redline.

I used my my air and look at my faces but how do u get those results you do? Print out

I too have had my share of cavities and dental issues with dry mouth. Didn't know until today, after doing research, that sleeping with mouth open is a main cause. I also can't stand the chin strap and am going to try mouth taping so I breathe through the nose only.

Xylamelts help but not a solution. Only last 5 hours or so. They are also supposed to make mouth less acidic.