Realistically, no. Firstly, as above they have different requirements in terms of work experience and knowledge of the profession. Secondly, dentistry is normally even more competitive than medicine and they will have a whole wait list of applicants who narrowly missed out on an offer that they can use to fill any spots for people that miss their offers. As above, you can ask, but expect to be told to reapply if you want to be considered for dentistry.