I would estimate between 60-75% of the class is SDA, with most of those coming from the "feeder" colleges. Are they going to ignore your application because you aren't SDA? absolutely not. Statistically are you at a disadvantage to get in if you aren't SDA? Yes.
Every year, like clockwork, someone posts a thread about LLU basically implying or overtly claiming that it is like a monastery or some cult-like school where they shove religion down your throat and you can't do anything fun. Unlike all the other dental schools in the US, Loma Linda does incorporate religion into their curriculum. This is manifested as: 1) at least one class where religion/Christianity is the main subject (note: it is NOT an SDA indoctrination class); 2) mandatory chapel attendance, not participation, on Wednesdays for the first 2 years except during summer; 3) an adherence to rules stipulating abstinence from tobacco or alcohol and 4) some prayers said before class and references made to God here and there.
I'm in my third year at LLU and I am not SDA. The people here are very friendly and, as a whole, seem to try and live as good Christians and treat others as a Christian should.
But seriously, if you didn't know enough about LLU to know it was SDA, why did you apply?