“Dentists should take longer to check teeth carefully before drilling and filling of cavities,” says Hayashi. “Teeth have self-healing and remineralizing properties, which should be encouraged first. Then, if you decide you must drill, go lightly. I tell my students to pretend they are feathers when using drills: Be gentle and avoid deep digging. Modern tooth-colored filling materials, many pioneered by Japanese companies, do not require deep excavation and can promote healing in teeth.”

One of Hayashi’s colleagues, Satoshi Imazato, professor of dental materials science at Osaka University, and a guideline coauthor, is working on filling materials that will contain anti-bacterial ingredients to fight decay.

“By the same token, deep drilling of teeth and filling with old fashioned metal inlays and crowns may be the sure way to hasten their loss,” adds Hayashi. “Drilling deeply weakens the vital tooth structure and may inflict lasting damage on the prospects of preserving the pulp that is the core of the living tooth. Excavating and filling locks the teeth into a potentially vicious downward spiral when the fillings fail and the dentist drills deeper.”

A lot more is at stake here than whether and how deep to drill and fill teeth. There are also critical training and cost questions. In Japan, public health insurance for dentistry seems to function well, unlike the U.K. But a closer look reveals a system that has deep flaws, from the training of dentists to clinical practice. Momoi admits that “we have the highest concentration of conceptual dentists in the world.”

This is because it is almost possible to pass the dental exams and get a license to practice without having seen the inside of a real patient’s mouth, let alone probed or treated a live person. Nairn Wilson, who knows Japan well, echoes Momoi’s concern: “The clinical practice of dentistry in Japan is not highly regarded internationally. The perception is that teaching focuses on theory rather than skill, let alone clinical excellence.”

Japan’s final, government-set exam to qualify as a dentist entails answering multiple-choice questions on a computer. Although some of the hundreds of questions that have to be answered within a strict time limit are fiendishly difficult, there is no practical test of dental skills, nor any need to prove that the candidate for examination has a patient-friendly attitude.

Japan’s 29 dental schools, 11 in government universities, such as Osaka, Hokkaido, Kyushu, one local government, and the rest in private universities, follow a government syllabus, which includes a course in clinical skills, where the students will be taught to identify and cut and drill teeth, but not in real patients.

Only a few dental schools have sophisticated phantom heads, mannequins that replicate the human mouth and can be filled with healthy or decayed teeth, and yell “ouch” if a student touches a sensitive place. Students in their final years can treat live patients, but only with the patient’s permission, which is mostly refused. Momoi says that at Tsurumi only 10 percent of the patients consent. Hayashi notes that patients are much more reluctant than 10 years ago to allow students to treat them.

One reason may be that in Japan even the university clinics have to charge health insurance rates, so the patient pays 30 percent of the bill, whereas in the U.K., university dental treatment is free, but the patient has to accept student care, under close supervision, adds Wilson.

There is a lot of waste in the Japanese system. In the 2011 dental licensing exam for the DDS qualification, only 2,400 of the 3,378 candidates passed, a success rate of 71 percent, or a failure rate of 29 percent. At one private university, the pass rate was 40.9 percent, 59.1 percent and 41.6 percent in the last three years. Insiders say that the health ministry adjusts the pass rate, not objectively, but according to the number of dentists it thinks Japan needs. Given the high fees — ¥6 million for the six-year dental course in government universities and ¥32 million in private universities — this is a wasteful way of weeding out unwanted candidates.

Hayashi cites health ministry figures that Japan faces a severe surplus of dentists, 18,000 too many by 2025. In 2004, Japan had 42,000 convenience stores, but 65,000 dental clinics. Japan has 74 dentists per 100,000 people, higher than the rich country average of 61, or the U.S. with 60, or the U.K. with 42. But Japanese make 4.3 visits to the dentist a year, three times more than some advanced countries.

As soon as the candidate passes the final exam he or she is free to practice on real patients. Recently, Japan decided that freshly qualified dentists should do a sort of apprenticeship in the seventh year closely supervised by an experienced dentist. But this may entrench bad old habits. It leaves the neophyte dentist to be taught clinical practices by an old hand who was probably schooled in drill and fill. Only a minority of Japanese dentists practice minimal intervention, and Momoi estimates that “very few” follow the good practices of the guideline.

Let’s not forget the “bill” part of the rhyming trio. One reason for continuing to drill and fill is that it is easier for the dentist to make money. The government health procedures reward completed procedures, not happy healthy patients. This is not Japan’s problem exclusively.

Wilson notes: “Around the world ‘drill and fill’ was the order of the day up until the early 1990s, given the challenge to treat a tsunami of untreated dental disease. With reductions in dental disease, at least among younger people, the approach needs to change to prevention and preservation. Funding agencies find this difficult when the systems for remuneration are based on objective ‘procedures completed’ arrangements. How do you remunerate for different levels of health and well-being?”

This is complicated in Japan because of government distrust of greedy dentists. Hayashi points out that some years ago government accountants discovered that dentists claimed for more protective rubber sheets — supposedly used and changed for each patient — than were sold by the manufacturers.

Beyond that is the multitrillion yen question of how long governments can keep funding dental treatment by public health insurance when populations are aging and budget deficits are ballooning.

Dentistry, even more than medicine, shades quickly into cosmetics and vanity. Japanese developments in faddy fashions, such as LED teeth, have only drawn attention to the fact that if you have money, your teeth are not merely for eating, smiling and showing your emotions, but a fashion statement.

But Momoi strongly believes that “the dental profession is not a business, but should be based on a conscientious sense of duty. We have a treaty with God, Buddha, Mohammed or Christ to respect people, in accordance with the Hippocratic Oath. In Japan, dentistry is based on the concept of public salvation; in the U.S. of individual salvation.”

This is a fundamental question that the guideline tries to answer and that the government has to grapple with: Is dentistry for the benefit of the patient — in which case the guideline offers a potentially more affordable more patient-centered system of health care? Or is dentistry a moneymaking business like any other — in which case should the government exit the cruel market and leave people to fend for themselves?

Kevin Rafferty, editor in chief of PlainWords Media, runs as fast and far away as possible from any dental chair, even one operated by his wife, Mikako Hayashi.

Guide to improving Japan’s dental system

• Improve dental educational and insist that licensing candidates have proven clinical and diagnostic skills and are patient-friendly.

There are practical problems. It is not workable, for example, to insist that tooth extraction or even filling be part of a final exam: How could an examiner ensure that enough patients with similar conditions turn up at the appointed hour?

Instead, insist on course work of up to a year in treating several patients and their conditions: Students would have case files and could be questioned, along with their patients. Patients should be given free treatment when treated by students — under the supervision of experienced tutor dentists.

• Largely dismantle the multiple-choice final exam by computer and have open-ended questions where students must diagnose and recommend treatments.

• Consider allowing universities to set their own exams, supervised by external examiners.

• Weed out surplus candidates before admission to university.

• Reduce the number of universities offering dentistry and encourage all dental universities to become centers of excellence.

• Insist on training or refresher courses for all dentists, as a prelude to regular recertification. The guideline says it should be revised every five years or so, to keep up with the latest knowledge. Isn’t it dangerous to have dentists practicing 20 to 40 years after graduating without testing that their skills are up to date? The Japan Dental Association gives points for attendance at lectures, but this merely continues Japan’s fixation with conceptual dentistry.

• Re-examine the financing of the national insurance scheme to reward dentists properly, but place emphasis on minimal intervention treatment and encourage patients to live healthy lives where their healthy teeth can outlive them.

• Revise the role and powers of the Japan Dental Association so that it is recognized as similar to its British counterpart, which advertises itself as the “trade union for dentists.”

• Set up a national commission (similar to a British Royal Commission) to examine the teaching, practice and funding of dentistry with membership of officials, academics, dentists and patients to report in two years. It could be a forerunner of a similar commission to look at medical, health care and social security systems. These issues are too important to be left to the bureaucracy and the whimsy of politicians, but need a public airing.


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