I would add that attending an inexpensive DS that offers specialty residencies is wise. You'll get 1st hand experience with the different specialty depts, specialist attendings, etc. Besides some shadowing .... not sure how a predent or dental student can actually get a true feel for specialties when their DS does not offer them. Once you decide on a specialty .... you can help out in the specialty residency program. I did this. Helped with the research projects for an ortho attending (who also wrote my LOR for residency) and an ortho resident. I was outside of the top 5 in my DS ranking, but I attribute my acceptance into ortho from my experience with my DS's ortho residency.