Hello,
Michigan has a pre-MSTP summer training program.
http://med.umich.edu/medschool/mstp/students/prospective/pre-mstp-program.html
If you're looking specifically for a dental related emphasis, you don't really need to join a summer program to do that. Research experience is one of the most important things that DDS/PhD programs look for. In terms of grades and koalafications, your GPA and DAT scores should be great, but if you can get into dental school, the question isn't your academic ability, but your ability to think independently about science and the work that you've done. If you can't speak with confidence about the research you've done and the professors that interview you here can't get a good sense of your passion for the science, then you're going to be SOL. I've spoken to several people about the DDS/PhD programs on the forums via PM so everyone has similar concerns.
Now, you don't need to "publish" to get into these sorts of programs, although it would help. I can only really speak about Michigan because I'm currently attending. We do the first 2 years PhD, with coursework from the graduate school and some classes from the dental school. We're expected to be in our respective labs pretty much full time on top of those courses. We do the next two years with the incoming dental class, and our respective 3-4 years left doing clinical requirements and dissertation work. We do three rotations with professors in the dental school (Oral Health Sciences department) and have the option of rotating out of the dental school if we're really interested. The only caveat with that is that there is a lot of paperwork the PI you're interested in must do, and you must do as well. It's very complicated in terms of funding also, but doable.
My research experiences weren't really related to dentistry, except my summer internship at UCSF with a dental professor there. The bulk of my experiences were in the lab as an undergrad for a year in a purely basic science lab and a lab tech working for an NIH facility for another year as the head researcher on their recombinant antibody project. Don't waste your time on these programs if you can get a meaningful research experience at your home school where you feel confident about the work you do, good or bad, and can stand your ground when they ask you questions.
In terms of quality of life, I love it here, minus the terrible, terrible midwest winters. Great bars, great people to always meet, lots of restaurants, karaoke, bowling, go karts, movies, cinema, theatre, basically anything a normal city would have. Also, Michigan football.
Lots of cool labs in all types of specialties:
http://www.dent.umich.edu/phd/home/current/documents
