A facility has neglected to brush my mothers teeth for 3 yrs despite my many requests to mgmt, the gums are red, the teeth are rotting off at the gum

I have asked that my mothers teeth be brushed from day 1 since she can not do that herself. She is in a wheelchair, immobile, and now unable to use either hand. After many meeting and daily, weekly requests with the director of nursing, the administrator, the staff and the floor manager, as to why they still were not doing that, over 3 years later her teeth are still not getting brushed and are now rotting off at the gums, have cavities, and her gums are sore. I'm afraid with this not being done daily she will develop an infection that could possibly get into her blood stream and cause major health issues or even kill her. They just ignore me, have not even relayed to the newer staff about brushing her teeth so that is still not happening as of last evening. I took pictures of her teeth last night as proof her teeth are not getting brushed. My brother and I are in to see my mom every day. Very rare that one of us is not there. And there are several other issues regarding care.