Is this teeth infection? Upon touching she was not feeling pain though.

[GretaChitti]

I brush my cats teeth one or two times a week. I have noticed her gum of one teeth being torned out a little. So I thought might be because of brush, as I use human kids brush of 1 year old. I changed to another brand of adult brush more soft and round shaped.
It’s not healing or the gum is not coming, I touched today no pain. So I applied little toothpaste their. Is it infected? Thank you in advance for sparing your time.

 

[Alldara]

Cats are very good at hiding pain. I would take her to the vet for that.