My gum above a crowned RC tooth became inflamed and painful after I flossed last week. Red w a whitish spot right on the gum surrounding tooth???

Aphthous ulcer. It's most likely a canker sore. It is painful, I get them sometimes when I eat acidic foods. You can put some oil of clove on it to numb it. It will burn a bit when you put it on but will go away within a few minutes. If your dentist has a soft tissue laser that can also help with the healing process. It should go away in about a week. Hope this helps!!!
Canker sore. is the most common oral lesions. Most ulcers, infections will clear up by themselves within a week or two. You should see your GP or dentist if the ulcer gets worse or lasts for longer than 2 weeks.