hello and welcome to HCM forum,
pyorrhea is a periodontal condition which occurs as a results of poor oral hygiene
, hereditary factors ans sometimes is associated with a medical condition,
it is good idea to guide your mother through this forum,
first of all if your mother is not all convinced on getting her tooth extracted ,then it is better not to force her, in fact take her to a dentist
and get her teeth cleaned professionally, do not worry about the teeth getting mobile after scaling,it is just a myth.
also, i would suggest warm saline rinses, antibacterial mouth rinses(3-4 times/day),
pyorrhea can increase the chances of heart diseases if she is diabetic,hypertensive or even if she is suffering from a present medical condition.
i wish your mother good health,