Junwu,
You should be aware that the bench test in Hawaii is very difficult and you only get one chance to pass it. We have a friend that took it and got a score of 74%. Passing is 75%. I doubt that you'll find anyone doing a review course for this specific exam. There just aren't that many people trying to obtain Hawaii licensure through that process. Hawaii has a population of about 1,200,000 souls and a population of about 1,300 licensed dentists. The island of O'ahu accounts for about a 1,000,000 of the population distribution. The majority of the population is of Japanese and Pacific Asian Island descent.
Even if you pass the bench test there, you will find their clinical exam to be very difficult, more so than other state's clinical exam. I'm not sure how many chances they give for you to pass the clinical though, but I think there is a limit for candidates who seek licensure after the bench test. My impression of dentistry in Hawaii is that there is tight little clique of practicing dentists in Hawaii and they would prefer that not too many new dentists join their club. Good luck though and please let us know what you find out from the Hawaii dental board.
Scott