This is a good link for the dentistry requirements:
http://pagingdr.net/info/index.php?option=com_content&view=article&id=207:2014-entry-minimum-scores&catid=56:gpa-and-offer-criteria As you can see unimelb doesn't require an interview, I think other universities (interstate) do.
Depends what you want to get out of your degree really. Biomedicine isn't looked upon favourably compared to a science degree, they are both considered equally. Just to list some points about both:
science degree:
-Freedom to choose your own subjects; subjects that are in your interest and that you think you can do well in, this can be difficult if you are indecisive.
-Larger cohort, potentially more difficult to make friends
-Similar and often the same subject that can be found in BBmed
biomed degree:
-For a major part of the degree, subjects are chosen for you, this might be useful if you are an extremely indecisive person but some students may find it a burden to complete subjects like maths for biomedicine, statistics and physics; which may not even seem relevant to the degree
-Smaller cohort; easier to make friends?
-Probably considered to be more competitive than science; averages in the biomed cohort may be H2A (75+) compared to a science cohort where averages may be H2B/H3 in some instances (reflective of the higher atar requirement)
-Larger focus on the health sciences in some subjects compared to the BSc; biology at first year for instance. In second and 3rd year however, BsC and BBmed become really quite similar, especially in 3rd year; where students in BBmed have more freedom in choosing their subjects. In 2nd and 3rd year students in BBmed will enrol in subjects that are also included in the BSc.