I would respectfully disagree that being on HRT would drastically affect your decay rate.
It does however, make common sense to look after your teeth with a few simple rules as dental work can be expensive if things get out of control. Transition costs are high enough without having to worry about preventable problems.
1. Teeth cleaned before bedtime (floss and brush)! The mouth dries out when you're asleep so there's no saliva protecting them so anything left on them when you go to sleep has hours on end to rot.
2. Watch the frequency of naughty stuff - it's not the quantity that's important - it takes the mouth an hour to clear sugars/acids after eating or drinking
3. If you notice something happening in your mouth, get it checked immediately (even if it goes away) - particularly if you've had sensitivity to cold/hot or sweet things. Better a small filling than a root canal and crown or even worse, having a tooth removed.
Common medications that would affect your decay rate:
1. Psychotropic drugs (antidepressants etc)
2. Corticosteroids
3. Blood pressure tablets - I'll give him spiro as a maybe - if the diuretic effect is high enough to cause your mouth to dry out
4. Chemotherapy drugs
5. Alcohol (dehydrates you, acidic, contains sugars)
The list goes on, but those are the most common.
