And it isn't always a good measure of educational quality. It is probably a better marker of caliber of student.
Reason being, there will always be students who desire nothing more than to practice general dentistry and have no desire to pursue even a single PGY of training. In this case, students only need score a 75 to pass their boards. And yes, many students feel fine scoring an 80 or an 85.
Those super high scores are seen many times in correlation with which school they attend, but most often those scores correlate BETTER with the students themselves. Meaning, students who did well in undergrad, marked high on the DAT, learned easily in dental school, and then blew the NBDE I out of the water.
I think there is a stronger correlation with high scores and students that are motivated to study hard and suceed, then there is between high scores and curriculum or institution.
My thoughts, no flames please.