your story line flows well but I would definitely include more of dental related experiences. It's nice to have your amazing rock climbing experience but to me it's sort of too fairy tale like instead of realistic. But I see how you wanted to relate that to the difficulty of dentistry.
Overall, I think it's pretty good, if you have any other club, volunteer, community services, etc, I would definitely bring it up to tie into your persona.
I just feel that your essay focuses more on other things rather than your interest in the dentistry. I had the same problem with my first draft, where I was writing more about my other random experiences rather than my dental work experience.
This is just my opinion.
Oh, you mentioned your 15 hours of volunteering but you didn't mention your shadowing hours. I think it would be better if you don't mention 15 hours, specifically, if you do, you should mention how much more you have toward dentistry. Ie. Shadowing, work, etc.
Good luck!
