Could you reuse your personal statement if you reapply the next cycle? Or would that not be good for schools because you assume they read it already? What if you apply to schools that you haven't applied to before?
i would revise your PS as best you can for reapplying... you want to improve your app as best you can, you dont want schools seeing that you took a shortcut
As others have mentioned above, try to improve it as best as you can. You could maybe even add additional dental-related things you have been doing / learning since you last applied. Show it to your advisor, peers, friends, family, dentist, and get as much input as you can.