Which unis to apply toWatch
For starters, there are about 2000 other unimaginative applicants doing just this, inflating the applications for those "best" four and thus reducing all of your chances of actually winning a place.
Secondly, arbitrary notions of academic superiority are especially pointless in dentistry (and medicine and vet med) unless you're intending to pursue a career in academia (which especially for dentistry is unusual and much rarer than the other two). Choosing the university that is located somewhere you can stand living in (and around, for placements in the last 2-3 years) for 5 or 6 years of your life is a much better idea. Particularly as if you hate where you live it will affect your studies, and if you do want to pursue some unusual academic and competitive area then your ranking will be more important than where you studied in the first instance.
Finally different dental schools have different styles and methods of teaching and one or another may be more appropriate for you. Doing the bare minimum of research into this isn't a great reach for a dental applicant. This, as above, will affect your academic career there, and how well you do within it.
I would suggest, if it's financially feasible, visiting some of the campuses you may apply to. If that's not possible (or even if it is) I would suggest you carefully consider the information available on their websites on how the course is taught, where placements are, what the accommodation facilities are and how long you will live in them (can you stay in university accommodation for the entire course, or will you be expected to move into private student accommodation with a group of friends in second/third year - also how they arrange accommodation for placements, if applicable).