Can a nursing home stop a family member from assisting their parent with oral hygiene?

My mom is in a nursing facility in Wisconsin. I have been helping my mom with her oral hygiene and cleansing her face and eyes. I have made a complaint because of the number of bruising my mom has on her body, in addition learned she fell out of bed three times. Now the nursing home has prohibited me from helping my mom with her hygiene. Can they do this? Please help..if anyone knows of a resource of family rights to their parents in nursing homes please let me know. Thanks, Linda