Please advise me on Gap Year ECs

I'm a graduating senior. I found a full time research tech job and I'm planning on applying to dental schools this summer. I'm planning on applying broadly but ideally I'd like to attend a research-focused school that would give me the chance to enter academia.

Would I be able to get into a top (i.e. Harvard, Penn, Columbia, UCLA) dental school with my current stats and ECs? This is what I have so far:
-3.9+ science and nonscience GPA, 23AA.
-160 hours of shadowing between two general dentists and a periodontist.
-180 hours of shadowing at a hospital with patient interaction.
-1000 hours of basic sciences research in the summers with a publication.
- Went on a week long service mission abroad to teach oral hygiene.
- Biology TA, notetaker, tutor.
- Member of a few clubs, gave a few oral health presentations to inner city schoolchildren.

I'm planning on doing more community service on the side while I'm working to reinforce my candidacy if I don't get in my first cycle. I'll be conducting research for my gap year job but I don't think I'll be able to get another publication out of it.

I'm thinking about volunteering at a hospice because it would allow me to interact with patients and improve my patient care ability. On the other hand, I could volunteer at a low-income dental clinic which may allow me to assist but wouldn't allow the same degree of interaction with patients.

If I had to choose one, which would you recommend? Could you please suggest other things I could do during my gap year to strengthen my candidacy for top schools in case I don't get in this year? I think the the only gaps in my application at this point is the absence of leadership experience.

Thank you so much for your help!
-Zbtb7