Articles

It Really Doesn’t Hurt A Bit

If you’re one of those people who shrink from a dentist’s drill you’ll be glad to know there’s a new machine that does the job with a jet of dust and is as painless as a tax refund

MAX BRAITHWAITE July 1 1951
Articles

It Really Doesn’t Hurt A Bit

If you’re one of those people who shrink from a dentist’s drill you’ll be glad to know there’s a new machine that does the job with a jet of dust and is as painless as a tax refund

MAX BRAITHWAITE July 1 1951

It Really Doesn’t Hurt A Bit

If you’re one of those people who shrink from a dentist’s drill you’ll be glad to know there’s a new machine that does the job with a jet of dust and is as painless as a tax refund

MAX BRAITHWAITE

THE DENTIST'S DRILL, which has been making liars out of honest men for years, is being slowly nudged to one side in the tooth-fixing profession by a new technique which finally permits a dentist to tell the truth when he pries open your mouth, smiles and says solicitously, “Now, this won’t hurt.”

The other day I had a tooth filled, and it really didn’t hurt. The operation was performed with a machine called an Airdent, which looks like a small refrigerator with vacuum cleaner attachments. It cuts into the enamel of your teeth with a fine stream of abrasive powder in the same way that a stone cut ter blasts out initials on tombstones with sand. It was invented fewer than ten years ago by a Texas dentist named Robert B. Black and it’s still being tested by a research institute at Ann Arbor, Mich.

But the Airdent is already being hailed as the most revolutionary discovery in dentistry since the gold inlay. In the United States more than forty dental colleges have started post-graduate courses on Airdent technique and about a hundred dentists have the machine in their offices. As the glamour gadget of the profession the Airdent has made at least three appearances on television.

At this writing there are five of the machines in Canada three in western cities and two in Toronto but more and more Canadian dentists are enrolling for courses at U. S. colleges and at the Ann Arbor institute, where they learn to operate the Airdent and place their orders to purchase a model for about two thousand dollars. One of the Toronto machines is at the Toronto University School of Dentistry, which plans to start a postgraduate course in the technique.

The job of drilling is in no immediate danger of being scrapped by the dental profession, because the Airdent can’t always reach the more remote centres of tooth decay. But the new machine can do about seventy-five percent of the drill’s work so painlessly that one authority has described it as the biggest boon to dentistry since the local anaesthetic. It is also a near-perfect cleaning instrument.

In an office on Toronto’s Eglinton Avenue Dr. Ralph Singer operates one of the five machines in Canada. A dark-haired, heavy-set, precise man of thirty-six, he has pursued new dental techniques ever since he graduated from the Toronto University School of Dentistry in 1938. He was the first Canadian dentist to complete the Airdent course and buy a machine.

His office has the usual tooth-drilling and pulling paraphernalia and, in addition, a beige-colored metal box about three and a half feet high standing next to the dentist’s chair on four rubber-tired casters. On the top at front is a set of dials for regulating the flow of abrasive powders that do the cutting and cleaning and the carbon dioxide gas that forces the powders under seventy-five to a hundred pounds pressure through a long thin rubber hose and a pin-point nozzle at a thousand feet per second. The nozzle is attached with a ball-and-socket joint to a handpiece slightly smaller and lighter than the old drill holder.

The Enamel Seemed to Melt

Hanging down the front of the machine, like an elephant’s trunk, is a large rubber hose which draws off used abrasive powder exactly like a vacuum cleaner.

Singer adjusted the dial controlling the cleaning powder (a carbonate of calcium and magnesium called dolomite) and showed me a stained old tooth set in a wax holder. Then he pressed a foot pedal attached to a hose at the bottom of the machine. A small, almost invisible stream of powder shot from the nozzle. He directed this at a dark stain at the base of the mounted tooth; in a few seconds the stain vanished.

Then Singer switched to the cutting powder (aluminum oxide) and directed the jet at the top of the tooth from a distance of about a quarter inch, moving it slowly back and forth like an artist using an airbrush. The enamel seemed to melt away, leaving a small neat hole in the tooth.

What happens if this tooth - piercing spray happens to touch your lips, gums or tongue? Singer pointed the nozzle, still spitting its thin spray, at his finger. He didn’t even flinch. The harder the surface the better the abrasive cuts, he explained. It has little effect on soft resilient tissues. Since the powders are not silicons, there is no danger of silicosis from the dust getting into a patient’s nasal passage; anyway, the vacuum tube draws off ninety percent of the powder almost as soon as its work is done.

The Airdent is making such an impact on the dental profession because it relieves the average patient from his almost traditional fear of the drill. Dentists expect, therefore, that when the Airdent is in wider use and better known their business will increase.

Singer pointed out that most of the discomfort (dentists don’t use the word pain) of the drill is caused by pressure, heat, vibration and boneconducted noises. Cutting through hard outer tooth enamel with a metal bur whirling at four thousand revolutions per minute requires from two to three pounds pressure and generates enough heat to burn. And the vibration and noise of the whirling drill are transmitted through the teeth and jaw bones to the bones of the ear and the skull surrounding the brain, making the drill sound and feel more like a hundred riveting machines than the delicate little instrument it is.

The Airdent has none of this. The particles of dolomite flying out the nozzle create less than half an ounce pressure -not enough to feel. Tests have shown that although the action of the abrasive on the tooth does create heat this is neutralized by the cooling effect of the gas stream. There is no direct contact between the machine and the tooth, so there is no vibration.

Now I would normally think no more of jumping into a dentist’s chair than of leaping into a vat of hot lead, but by this time I had convinced myself that the Airdent was everything Singer said. I stopped sniveling and climbed into the chair. He prodded around in my mouth and finally announced that he had located a suitable cavity in a back tooth. I braced myself.

Singer held up a six-inch square of thin rubber with a small hole in the centre. This was a rubber dam used to isolate the tooth so that the Airdent can work on a completely dry surface. Moisture on a tooth causes the powder to form a paste and nullifies the cutting effect. He fitted the hole over the tooth and shoved the rubber into my mouth until it felt like a piece of broken balloon that you suck into your mouth to make a smaller balloon. In a mirror I was permitted to look at the lone tooth sitting up there high and dry—waiting.

Singer meanwhile had decided on the size and shape of the cavity he wanted to cut; unlike the drill, the Airdent cannot be used for probing around a tooth. And he had determined the amount of pressure he would use to do the cutting. Now he deftly set the proper dials while his nurse stepped over to the side of the chair with the vacuum hose. She held the suction hood close to the side of my mouth and turned it on; it purred like a vacuum cleaner.

It Works Faster Than a Drill

I heard the familiar words, “Open a little wider, please,” closed my eyes, squeezed the arms of the chair in my fists and tried to shove the back of my head through the head rest. Above the hum of the vacuum apparatus I heard a faint hissing sound, but I felt absolutely nothing. I opened my eyes to see when he was going to start on the tooth. He was grinning and it suddenly struck me that he had finished.

He started to work again and this time I kept my eyes open but still felt nothing. He took the nozzle out of my mouth and handed me a mirror. I looked where he pointed and there was a neat round hole in the side of the tooth. It was ready to be filled, but to smooth it off he decided to use the drill for a few seconds.

“It will give you a chance to compare the two methods,” said Singer.

Then I felt the heat and the vibration and the pressure of the drill and I didn’t enjoy them any more than I ever had. Singer explained that dentists will still need a drill to prepare cavities that can’t be reached by the Airdent and to enlarge them from the inside. But the new machine does most of the hard outside cutting, and does it much faster than a drill.

As his nurse mixed the amalgam to fill the tooth, Singer told me that he’d used the Airdent on about fifty patients up to the time of my visit, and about twelve had received îhe treatment without a local anaesthetic; all said they preferred it to the drill with an anaesthetic. Singer uses the Airdent extensively for cleaning teeth—a job for which it is well suited because the abrasive powder reaches into grooves and crevices which are almost impossible to get at with a brush or buff.

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He became interested in the Airdent technique when he read about it in dental journals more than a year ago. Then last summer the Kellogg Foundation Institute at Ann Arbor, which is sponsored by the W. K. Kellogg Company (breakfast foods), announced that it was starting a post-graduate course in the use of the new machine. Singer was among the first to enroll; he took the course in January and got his machine in March.

“The abrasive technique will probably be to dentistry what the wonder drugs are to medicine,” he says. “It won’t do everything, but it will make cavity preparation a lot easier for both patient and dentist.”

Several leading U. S. dental authorities who have studied the technique are similarly enthusiastic, although many dentists in Canada and the U. S. see the machine merely as another expensive piece of equipment they will have to buy to please their clients.

In an early report on the machine Dr. William R. Mann, assistant director of the Kellogg Institute, said that tests on dozens of patients had revealed that the only sensation any of them felt from treatment by the Airdent. was “a slight tickle” and “none has believed that a local anaesthetic was desirable.” This meant that dentists would benefit “by working on patients who are rot nearly so apprehensive as many are now” and by being freed from the concern “over the possibility of a bur jumping or a patient moving while an instrument (drill) is revolving in the mouth.”

Dr. John M. Spence of the University of Illinois was quoted after the machine had its official debut before one thousand dentists at the Greater Chicago dentists’ convention last January: “Patients will insist we use the

new technique because it does not subject them to pain.” And Dr. Warren Williams of Loyola University said: “We can prepare cavities which would not have been possible to prepare without a local anaesthetic.”

The man who gave the Airdent to dentistry was Michigan - born Dr. Robert B. Black, a graduate of Albion College and Northwestern University School of Dentistry who started up a practice in Corpus Christi, Texas, seventeen years ago when he was twenty-five. Black developed almost as great a horror of drilling teeth as his patients who underwent the ordeal, and he resolved to eliminate the drill.

In his research he investigated every known commercial method of cutting hard surfaces and discarded them one by oneexcept sand-blasting, which is used for cutting letters and figures in granite. In 1942 he rigged up a crude blasting outfit and began w'orking on teeth he’d removed from his patients.

After a year of tests and changes both in the machinery and the cutting agents he enlisted volunteers and gingerly tried the equipment on live teeth. There were no howls of anguish from the volunteers, but the technique was slow and expensive because nozzles had to be individually cast and were worn out. by the abrasive powdeis in less than a minute’s use. He didn’t have a vacuum apparatus and the grit had to be washed out of his patients’ mouth and teeth.

Nevertheless, he eventually gained a reputation in his district as the denti-t who fixed teeth a different way.

In 1945 Black decided he’d gone as far as he could go alone and made a contract with the S. S. White Dental Manufacturing Company of Philadelphia to do research on the machine. The company solved the problem of worn-out nozzles with an alloy that resists abrasive action for as long as six months and developed the piesent compact unit that fits neatly into a dentist’s office. Then in 1948 the Airdent was introduced to the dental profession through the University of Michigan Dental School. Since then, testing of the machine and instruction on its use have been directed by the Kellogg Foundation Institute which is connected with the university.

Dentists are buying the machine almost as fast as they can complete the six-day courses required by the S. S. White Company before they can get an Airdent and as fast as new' models can be produced. Diversion of aluminum supplies into war goods is slowing production of the new equipment—one of the reasons the Airdent may not be in general use in Canada for some time.

But it looks as though sooner or later some relief is in store for most of us drill-jumpy people.