Key is, 'in demand specialties' - prosth is not on the list. Notice the document you attached is not dated. There are additional criteria too regarding eligibility to commission (citizenship) and licensure. Go read up on the MAVNI facebook page. It does not look like MAVNI is open right now. There are MAVNI applicants from before the program was closed that are still waiting, some as many as two years.
If you are able to get in to see an Army recruiter, healthcare or regular, let us know if MAVNI is open for any Officer positions. Maybe one of the recruiters that posts on here occasionally knows if it is open for any Dental Specialties.
Edit: Prosthodontist is on the list for Reserves but the list may not be current.