Did you ever wonder about the scenario in a dentist's office when he casually mentions it's time for some new bite-wing X-rays? First, they cover you from neck to knees in a heavy lead shield. Then everyone goes running out of the room as if a bomb is about to explode.
Well, it turns out most of that is not only unnecessary these days, it's play-acting. "Our equipment is so low-dose now, we can stay in the room for dozens of X-rays a day," my dental hygienist told me during my recent visit. "We still use the shield and leave the room, because it's what people are so used to. It seems to make them more comfortable."
Dental X-ray equipment has become much safer in recent years thanks to digital imaging. A typical modern dental X-ray machine will not expose you to more than about half a millirem for a bite-wing scan. That's equal to the radiation in five bananas, and it is less than 5% of the dosage from a chest X-ray (it's hundreds of times less than a CAT scan of your chest).
Why did I bring up bananas? Bananas have suddenly become the hip way to compare radiation doses because a typical banana contains the natural radioactive isotope potassium 40. Other foods rich in potassium like potatoes also contain radiation, but the idea of comparing radiation levels to bananas is certainly more fun. There's even an acronym—BED, for banana equivalent dose.
Old dental X-ray machines gave you a 50-banana dose—10 times as much as today's newest equipment. Yes, using bananas as any kind of measurement is kind of silly and wildly inaccurate when you're trying to evaluate something like the banana equivalent dose of radiation leaking from the Fukushima nuclear power plant (about 75 million bananas), but it can put low-dose radiation exposure into perspective. For example, flying in an aircraft at cruising altitude for one hour is equivalent to 1 millirem, or 10 bananas, or two digital dental X-rays.
The average American gets about 620 millirems of radiation exposure a year from airplane flights, granite countertops, radon in tap water, working in concrete buildings, eating Brazil nuts (one Brazil nut has a BED of 2) and cosmic radiation. Your dose of radiation from the sun—cosmic radiation—escalates as you move higher than sea level—about 26 millirems a year in Washington, D.C., and 52 millirems (104 bananas) per year in Denver. That's because 80% of the oxygen on the planet, not to mention other gases like nitrogen, is in the first 5,000 feet above sea level. That thin blue band around Earth that mesmerized moon-bound astronauts is really thin. In Denver, there are far fewer gas atoms in the atmosphere between you and the sun to deflect cosmic radiation. The point is that unless you want to live in a radon-free cave (unlikely you can find one) background radiation is omnipresent.
You can take a quick quiz to calculate your personal annual dose at this link.
While you are contemplating how much radiation your lifestyle exposes you to, think about this: Why does dentistry lag the medical-tech revolution? The last great dental invention, the high-speed drill, is more than 50 years old. Those new low-dose X-rays in the dentist’s office are spin-offs of other technology.
I was wondering about this recently as my dentist raised a huge syringe and moved it toward my mandibular nerve, hoping for a complete blockage of pain sensations that would travel up from the inferior alveolar nerve in my lower jaw. I was not happy. The shot didn’t numb the nerve very well. Before I could say much, there was that giant syringe headed my way again. The dentist looked straight into my mouth and muttered, "You'd think in the year 2013 we'd have a better solution to numbing your jaw." You'd think.
So no one in his right mind likes going to the dentist in this age of high-tech. And therein lies a void worth watching. Dentistry's dark ages cannot last. Everyone needs to go to the dentist at least twice a year, although a lot of people don't because they perceive dentistry as full of discomfort and archaic devices. Think of the potential market awaiting tech that changes that perception. Someone will.
Dentistry is ripe for high-tech blockbusters. When the high-speed air-turbine drill was invented by a New Zealander back in the late 1940s, it became the must-have piece of equipment for every dentist in the world. Current drills operate at 400,000-800,000 rpm, and now they’re electric, instead of air-powered. But along with those drills running at truly amazing speeds came heat from the friction of the burr bit grinding away at your enamel and dentin. Nerves do not like heat. So the drill needs water to cool it. And you need really good anesthesia. The days of toughing out a filling when low-speed pulley-driven drills were used is over.
It's strange that people don’t take what goes on in their mouth more seriously. Poor dental health is now linked to heart attacks, Alzheimer's disease and colorectal cancer. And the older you get the more likely you are to have an aggressive cancer begin growing in your mouth and on the tongue (the most blood vessel-dense part of your body). Only a dentist is likely to notice one of these cancers early on.
Still, survey after survey shows that half the adult population is afraid of going to the dentist. And a study in Britain shows that women are six times more afraid of the dentist than men.
Dentistry talks a good game of being painless in the new millennium, but here's the state of that art: Patients are advised to develop a hand signal to let the dentist know they are uncomfortable during a procedure so the dentist can stop for a break. And dentists are advised to be kind and gentle and to be sensitive to patients’ tensions. That’s the best answer dentistry has in 2014?
And these dark ages are not just about pain. Now that so-called "silver" fillings full of mercury are taboo, long-term, reliable fillings for cavities are nonexistent. Composite fillings don't last even half as long as mercury fillings can. Of course, gold lasts forever, but a gold inlay in your tooth will set you back about $2,500. More composite fillings more often to replace those that go bad brings that syringe back into play.
Worse yet, the new hole drilled into the tooth for the next filling has to be just a bit larger. That scenario doesn't work forever. Too many repeat fillings in the same tooth spell C-R-O-W-N. Implants are a relatively new and developing technology that offer new hope for lost teeth, but what they put on the implanted post is essentially a crown, the same technology offered to your grandparents.
Meanwhile, last November, the Centers for Disease Control released its first report about dentistry. The study says half of all Americans aged 30 and older have periodontal disease. Does that mean they don’t go to the dentist? Perhaps many are unaware of an actual technological breakthrough in the ancient art of toothbrushing: Philips' Sonicare electric brush that combines sound waves with vibrating bristles. My hygienist says she can always tell which of her patients use the Sonicare—their gums are healthier and their teeth far cleaner. She loves the Sonicare, and uses one herself, but she is quick to say that a low-tech part of that toothbrush is what really helps the most. The Philips system vibrates like hell as you're using it and then every 30 seconds stops for a brief moment. The break is obviously intended to signal that you've spent enough time on one quadrant. The idea is to start with one quadrant of teeth and move to the next every 30 seconds. "What's really helping people the most with this system is that they’re psychologically pretty much forced to brush for a full two minutes," the hygienist says. "It's the two minutes twice a day, more than the sound waves, that really makes the difference."
So while the dentistry PR machine points to implants, electric toothbrushes, improvements in composite fillings and "painless dentistry," it’s really still a mom and pop operation. And that makes it a natural for consolidation and upgraded technology. One company trying to drop into that space is Clear Choice. It advertises implants and new teeth in one day, but dentists warn that the kind of patient with the exact circumstances that allow that to happen is very rare. Nonetheless, both the Invisalign clear orthodontic technology (ALGN) and Clear Choice implants show that entrepreneurs are beginning to notice "modern" dentistry. May the competition begin!