Dry mouth could very well be the issue. You should look at meds you are taking that could be causing this and see if adjustments can be made.I'm aware everyone with bad oral care clams this, but I do genuinely take great care of my teeth. I brush 2-3 times per day without fail, floss every other night and regularly use mouthwash. The only sugary / acided food I consume are drank with a straw.
I have noticed quite severe dry mouth recently. I'm not sure if this is related to my hormonal issues.
The rate at which my teeth are decaying in relation to my dental hygiene and diet suggests that something more severe and worrying is going on.