Ask any gaijin living in Japan about dentists, and you'll be sure to get an earful. While Japanese dentists are good at fixing teeth, they're famous for making you come back dozens of times to finish your dental work, instead of getting it out of the way in a few visits. Once I had some work done on three teeth that took an incredible 18 months. I believe Japan's dentists take so long to work on teeth because of the way insurance is structured -- they're only allowed to charge a certain amount to the system each day, so they spread it out as much as they can. Like men whose job it is to stand by the road and wave a flashlight to let you know there's road construction going on and NHK employees who knock on millions of doors to collect the $20 monthly fee from households in person, Japanese dentists are an unfortunate symbol of Japan's lack of efficiency in some areas.
This is the best reason to go to dentists: hot, hot oral assistants who clean your teeth for you. I just know there's a major Japanese fetish for having your teeth cleaned by a beautiful woman. I'd go every week if they'd let me.