BODY WATCH : Filling a Need : It’s Illegal but cheap. India’s sidewalk dentists do big business--despite medical officials’ cries of quackery.

Balvinder Singh, 19, plies his trade on a bustling overpass that crosses a railroad track. For 65 cents, the hulking high school dropout will pump a pedal-driven drill with his bare foot and bore into a customer’s tooth.

Singh has no formal education, and what he does at his sidewalk stall in the Indian capital’s historic center is patently illegal, not to mention painful and potentially perilous in the era of AIDS. But Singh says his customers, who sit on the ground, their jaws wide open, as bullock carts rumble by, are quite content with his type of free-lance tooth doctoring.

“It is our livelihood,” explains the young bearded Sikh, a third-generation member of his family practicing open-air dentistry without formal training or a license. (His brother Nirmal runs his own tooth-doctoring stall.)

“We’ve been doing this since my grandfather’s days,” says Balvinder Singh, “and until now, not a single patient has come back with a complaint.”

The sidewalk dentist won’t give his customers a guarantee, but he cheerfully promises to fix any problem they may have. And if patients don’t like his rates, they are free to try to bargain them down.

The Indian medical establishment, which boasts some world-respected practitioners of the healing arts, thunders its disapproval over such free-lance forms of heath care, and courts have ruled that the unsanctioned practice of medicine or dentistry, which Indians call “quackery,” is against the law.

But all of that doesn’t prevent a half-dozen “dentists” working alfresco from competing for customers on Singh’s overpass near New Delhi’s main railroad station.

“It is illegal anyway, whether removing teeth or selling medicine,” complains Dr. Jagdish Sobti, honorary general secretary of the Indian Medical Assn. “Even after a verdict was given by the Supreme Court last year against quackery, nothing much has been done to curb it.”

The association, which represents India’s more than 365,000 licensed doctors, has filed numerous complaints, but Sobti says that in most cases, the police and municipal authorities have done nothing.

Even if officials do pounce to shut down the vendors of miracle cures, bearers of dubious degrees or practitioners of other forms of quackery that thrive throughout India, “they find some other site, and start all over again,” Sobti says.

In one infamous case in New Delhi last year, a “healer” operated on a pregnant 35-year-old woman, and tore out her intestine, thinking it was a snake that had burrowed into her body. The woman died.

Of course, the root cause of the problem with quackery is that such health care is the only kind hundreds of millions of Indians can get--if they get any at all.

“It is the poor who come to us on the sidewalk; people who are rich can go to the expensive clinics,” explains Singh, who compares his skills to those of a gas-stove repairman.

Singh works without Novocain, without even a dentist’s chair or white smock. He uses a metal scraper to hack and gouge away at a patient’s cavities. It can be excruciatingly painful. But it’s what the clients expect.

“My tooth was broken, and I came here and got a new one. It is as good as new now,” says Raj Kumar, a handyman in a stockbroker’s office, flashing a smile to show off his man-made lower incisor.

Singh’s pliers and forceps sit on a dusty red sheet of plastic. The instruments are cleaned by dunking them in a solution of potassium permanganate, but in general, the conditions in Singh’s “office” would horrify mainstream dentists and their patients. A bedsheet suspended with rope is the only protection between Singh and the sun. When it rains, he closes shop.

Around the tooth doctor’s stall rages the pleasant chaos of an Indian marketplace: hawkers selling plastic wares, porters struggling by, their backs bent double, small Indian-made sedans trying to zip around carters dragging their balky wooden vehicles.

In all this bustle, Singh’s signboard, a beautiful, smiling set of teeth, stands out. His location, he thinks, is ideal: People walking by who have tooth problems notice his sign and stop.

“I get around six to seven customers a day,” he said one recent summer afternoon as he waited for a new patient. Most are day laborers. For 65 cents, Singh will drill and fill a tooth with zinc oxide cement; a silver filling costs about $2. (A legitimate dentist in New Delhi charges about $5 for a temporary filling and $6.50 for a permanent filling.)

“The prices are not fixed; they vary, as the customers do a lot of haggling,” Singh said. In a typical day, he clears 100 Indian rupees, or about $3.

The young man, who occupies the same corner of sidewalk where his grandfather set up shop in 1947 after the subcontinent’s partition, recognizes he has limits. He will not pull teeth or treat complicated dental problems, he says.

“At the most, I apply a medicine and ask the patient to go consult a doctor,” he says. “I specialize in making false teeth and filling cavities.”

Crafting a set of dentures is the summit of Singh’s art. He takes impressions of a patient’s gums, then pours a pinkish solution into the mold. The individual plastic or ceramic teeth, which he buys in the marketplace, are then carefully stuck into the solidifying solution as one would place candles on a birthday cake.

For the finishing touch, Singh grinds down the denture’s pink gums so they fit comfortably between his customer’s jaws.

The false teeth are the most expensive item that he and New Delhi’s other sidewalk dentists sell. A complete set, uppers and lowers, costs from $11 to $24.