Normally a pilonidal cyst
gets filled again if it is punctured only.
Permanent treatment of pilonidal cyst or abscess
involves surgical excision ( MARSUPILIZATION ).
After excision,the wound is packed daily and it may take 4 to 8 weeks to get healed completely.Since it is healed now you dont have to do any thing at the moment.But if it recurrs,then You must consult a surgeon for proper examination and proper treatment.