You still can! I would make a big push your spring semester to do well so it can average out this fall semester. If your school is like most dental schools, your rank is mostly determined your first 2 years or so. If you finish your first year in a low spot, it will be hard to climb your way back to a competitive rank.
Specializing and your competitiveness depends on the speciality. I had co residents that didn't have the best grades but had shown interest in pediatrics, a good attitude and experiences to back it up. However, compared to ortho, you can have all the interest in the world and a good attitude but without the numbers it's hard to get your foot in the door for interviews. I also had some classmates that didn't get into their desired speciality the first time, did an AEGD/GPR/externship, re-applied and got in on the second go.