As I understand from your post you developed parotitis
twice and you were treated by drainage
of the pus.
Well you can avoid it from coming back by maintaining a good oral hygiene
. Get a full mouth oral prophylaxis done by a good dentist
. Ask him to tell you how to maintain the good hygiene. regular brushing atleast twice daily, use of chlorhexidine
mouth wash on regular basis, warm water with a little salt gargle atleast three times a day. all this will help you to maintain a good hygiene and hence prevent recurrent attack of parotitis.
In case the cause is some thing else like a viral infections then it has to treated symptomatically but even in that casse a good oral hygiene is mandatory.