Hello and welcome.
Thanks for sharing your concern.

Please note that the strips could contain abrasive material,which can further damage your teeth and gums.
Please discontinue it immediately.The damage caused will definitely take sometime to heal.It would be nice if you can see your dentist and get an x ray done.
Hope it helps.
Thanks.
Take care.

Thanks for your query, I have gone through your query.
The inflammation of the gums after using teeth whitening strip could be a chemical burn or allergic stomatitis leading to desquamative gingivitis. Consult a oral physician and get it ruled out. You can take topical anesthetic and analgesics like anabel gel. apply 3-4 times daily before food.
I hope my answer will help you, take care.

Thanks for using Health Care Magic.

Read your query.

Tooth whitening is a chemical procedure which is usually done under controlled supervision and with good isolation.

The lesion caused on your gums will be due the chemical burns from the whitening strip due to no proper isolation of your gum area.

I would advice you to do salt water gargling or betadine mouth wash gargling .
Apply mucopain /dentogel on the lesion till symptoms are reduced.

Avoid brushing on gums to avoid further trauma.
If still persistent , consult your local dentist.

Hope this was helpful.
Thanks and regards.