It depends what university you want to go to. In NSW there is only 1 undergraduate dentistry course, at CSU orange. Entry is based on ATAR or university results and interviews, so you can enter straight from high school. University of Sydney also has a dentistry course however it is graduate entry, so you must already have a bachelors degree and entry is based on results from your undergrad degree, the GAMSAT (like the UMAT but for graduate entry), and interviews. USYD does have a bachelor of oral health also which is an undergrad degree, and entry is based on a combination of ATAR, a PQA exam and interview. This course is what I am currently doing and it is part of the faculty of dentistry, but qualifies you as a dental hygienist or dental therapist, not a dentist.
There are a few undergrad and graduate entry degrees available at other universities around the country but I am not confident on the exact details of these so I advise you check out the UAC guide or just search around online.
There is like 3-4 undergrads. CSU is the one in nsw. JCU is in qld. UQ has a guaranteed entry. GU is in QLD as well and has guaranteed entry i think.
I personally got an offer to study dent at CSU but rejected it to pursue medicine. If you need help with your application for CSU or any other questions just inbox me coz i ceebs typing everything out.