I think it'd be quite fulfilling, since you'll be spending most of your days doing them (fillings).
Bad pun aside, here's my opinion:
- if you feel deep down that you want to pursue medicine, then do it. Don't let other people's opinions sway you; but do your due diligence and go in knowing what you'll have to face;
- if you stay single, at least till you finish residency, you won't have to worry about your professional life encroaching on your personal one;
- I'd soft-pedal the shadowing of chiros in your personal essays, if you do apply to med schools.
BTW - no need to post the same exact message on 5 different discussions.