unfortunately, lupus can effect many different parts of our body.
if your blood is effected, then anything that blood circulates through, can also be effected.
as your gums are susceptible, to good blood flow, this may be part of the issue.
also as you said, dry mouth makes it harder for our saliva to interact with the food, washing it away, and cleansing our teeth also.
once you have a small decay started,.... the fact that we have suppressed our immune system also assist with this decay.
so all in all, it is a wonder we have any teeth left
When you're stressed, You eat Ice cream, Cake, Chocolate & Sweets. Why? Because stressed spelled backwards is DESSERTS.