The reason for special toothpastes or mouthwashes, one common and good one is Biotene, it is used for "dry mouth" which when the saliva production is altered by medications as mentioned, hormones, and decongestants like ones for sinusitis, etc. can contribute to tooth decay.
This happens with many of us just from menopause and hormonal changes during that "time of month", digestive problems, and diabetes can cause gum and tooth problems due to chemical changes within our bodies, so this is not just confined to the us of AD's. I used Biotene and still do to rinse my mouth, helping to keep the right balance, anyone can use these products, little pricey but excellent for our gums and teeth. An added note here, everyone should brush and floss their teeth daily for best oral care, regardless if on certain medications or no medications, good oral hygiene is important. LD, I wouldn't get all upset over this, just keep this in mind, oh, and another thing chewing a sugarless gum or Biotene gum will help reduce the effects of "dry mouth" so you may consider adding that if you experience this problem.
I keep with my regular visits to the dentists, besides the usual cleanings they check for any receding of the gums, treatment for that often requires scaling if there is any receding happening, I've had those treatments, they are painful but terrific in returning the gum/tooth back to a healthy status, but that is a whole other issue. . .don't worry about all of this, just keep up with brushing, flossing and rinses, you'll be fine

"darkeyes"

In giving advice seek to help, not please your friend
SOLON