What is permanent cure?
Permanent restoration of the natural state of health from a deviated state is, "Permanent Cure".
Why permanent cure is a factor of "ideal cure"?
If cure is not permanent, it is "palliative treatment", in which the morbific dynamic agent is suppressed, not eliminated.
How permanent cure can be achieved?
By applying the nature's law of cure.
When permanent cure will be achieved?
When a similar and stronger potency will be applied.