I am actually enrolled right now in Johns Hopkins Advanced Academic Programs Biochemistry class. It was my only option for taking biochem before dental school and I have to say that I do think I've learned a lot. This particular class is relatively time-consuming but doable while working full-time. The program (curriculum, professors, etc.) is very solid in my opinion and Johns Hopkins is a very reputable university. That said, I do think this biochem class is slightly less work than a regular biochem class would be. I'm glad I'm taking it because it has forced me to read through the material, prepare for quizzes, exams, problem sets, discussions, etc. and become familiar with a difficult subject matter prior to seeing it in dental school. I have no idea how an admissions committee would look at this kind of degree--I would guess it varies at each school. It's probably better than nothing, but at the same time, it probably is not as highly valued as one from a traditional program.
I would suggest you contact the dental schools you are interested in and ask how such a masters degree would be considered.
Feel free to PM me if you have any questions.
