I would go to the University's student services and utilize their resources in developing strategies to combat bullying. Document everything, even microaggressions as much as you can. This on top of talking to your student affairs dean at the school. Talk in confidence to your student leadership that you trust. There may be also an anonymous integrity "tip line" that you can report any incidents.
ADEA recently pushed out a webinar among members of the dental education community about the concerns of bullying, focusing on how dental school administrators should be more responsive to bullying that occurs, especially when students attack other students in-person and online. Certainly if it crosses discrimination law, this will be extremely problematic and subject the university (not just the school) to legal liability.