Research is not necessary and not as important as people make it out to be. Its particularly more important to have a strong oGPA, sGPA, BCP, DAT score and LORs. As long as you have the 100+ hours of shadowing, you'll be absolutely fine and can still get admitted w/o doing any research.
Hey man.
Like they said, research is not necessary. Although, if have done research it would definitely help you. For example, if you apply to research powerhouses like UCSF or Harvard, thats something they like to see in applicants. Not to say that there aren't people who have gotten in those places without research but its def something they prefer.
I strongly advise you to set up a meeting with the dental school before you apply. It lets them know that you are truly interested in their program. In addition, they can recommend ways to improve your application before you apply but they won't offer advice after you after you apply. Good luck!