since the time period written in your is long i.e 6 months.
if it is because of irritation, then it would have gone after deep cleaning.
swelling usually subside in 3-4 days maximum after removal of irritants.
if you still feel stucking sensation in your upper inter dental papilla you need to go for gingival re contouring or you can say gingivectomy
In this procedure they will reshape your gum line and remove the thick pad of gingiva in between the tooth area.
as you had already seen a periodontist, consult him again and go for re shaping of gums.
Dr. Vishal Jain