For certain people, there’s one sound above all others that strikes fear into their hearts and makes them want to run screaming for sanctuary: the high-pitched whine of a dentist’s drill. Presumably dentist-phobes fear the noise because it’s associated with the rotten part of a tooth being drilled away, but experts say the noise itself triggers a strong reaction. According to ABC News:

“It’s been demonstrated that people’s blood pressures rise as soon as they hear the sound, even if they’re not sitting in the chair yet,” said Dr. Mark Wolff, professor and chair of the Department of Cariology and Comprehensive Care at the New York University College of Dentistry.

So how to help these unfortunate souls? Researchers have come up with an idea: cancel out the shriek of a drill to cancel out the fear. After ten years of development, dental engineers now have a prototype device ready, and they’re looking for investors to bring the invention to a dentist office near you.

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Oh, the glorious future: Eat as much sticky candy and drink as much soda as you want! Go to bed without brushing your teeth! Never have to hear that horrible whine of the dental drill again!

Cavities could one day become a thing of the past, as new research is decoding how our mouth bacteria are able to attach their dirty little mounds of plaque to our teeth, and is suggesting ways we might be able to outsmart them.

Cavities come from bacteria that live in our mouths and digest sugars in the food we eat, producing tooth-dissolving acids. The most annoying tooth-bug is Streptococcus mutans, which causes tooth decay. The bacteria use an enzyme called glucansucrase, which converts sugar into long sticky chains that allow the bacteria to glue themselves to the surface teeth. Once they’re in place, they can start in on the acid production.

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In late November, Indian dentists set to work filling the largest cavity they have ever seen. Their patient, Devidasan the elephant, had a 20-inch-long crack in his tusk that had caused him pain for over five years, kept him from participating in festivals, and posed an infection risk.

Dentist CV Pradeep performed the unprecedented operation, which took two and a half hours to complete. The dentistry team used 47 times the amount of resin they would have used to fill a human tooth, and they modified their tools for use on the elephant’s tusk, Pradeep explained to BBC News:

“It was literally an elephantine task, because we had to find specialist equipment and modify it,” Dr Pradeep said. “The main difference between this and a similar operation carried out on humans is that we were not able to use X-ray screening, because none of our mobile X-ray units was large enough to suit the elephant’s needs.”

Devidasan was kept awake during the procedure, but the dentists report that he was fully cooperative. The dentists used the same procedure they would have for a cracked human tooth–just on a much larger scale. Pradeep told BBC News that Devidasan looked much happier after they were done with the filling. He is now fully healed and is back to participating in Hindu festivals.

This was the first elephant tusk-filling of its kind, so the dentists aren’t sure how long it will hold. They estimate it will stick for at least a few years, depending on how quickly the tusk grows.

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Image: Wikimedia Commons

This could mean an end to fear and loathing at the dentist’s office. A new (allegedly) painless blowtorch-like device is being developed that uses a thin beam of plasma could kill oral bacteria in cavities. A plasma is an ionized gas—one in which some of the electrons are stripped away from their atoms.

The plasma kept the dentin, the fibrous bonelike material that makes up most of a tooth under the outer enamel layer, intact, while reducing bacteria 10,000-fold.  This means that plasma jets could be used to wipe out the tooth-decaying bacteria in cavities–a procedure that normally requires the use of a painful dental drill to grind away the infected portion of tooth.

The plasma being used is a “cool” plasma with a temperature of just 100 degrees Fahrenheit. When it fires, it charges the oxygen gas around it, which creates reactive molecules that break down and destroy the bacteria’s cell walls, killing them in the process.

But here’s the bad news: If you have a gnawing cavity right now, there’s no point putting off a visit to the dentist. Researchers say it will take three to five years for the new plasma drill to make it to the dentist’s office.

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Image: Stefan Rupf

Many children are anxiously awaiting Halloween this weekend. But with all these sugary treats come a price: cavities. In fact, one out of every four children in the U.S. currently has at least one cavity in their baby teeth, a number that’s the highest it’s been in 40 years— and has been blamed on today’s sugary diet. Even worse, British researchers found that when kids consumed candy every day, they were more likely to be criminals when they grew up.

This Halloween, two Michigan dentists, Shawn Morris and Daniel Simmons, are encouraging kids to turn in their candy for cash. The mission is called Operation Gratitude—children will receive $1 per pound of sweets, so the dentists can collect a large candy stash. The candy, however, won’t go uneaten: The dentists will send it to U.S. troops stationed in Iraq so they can hand out the candy to local children.

So what is the incentive for candy-heavy children to turn in their loot? Hometownlife reports:

Youngsters who trade in their candy — a maximum of five pounds per child and total 1,000 pounds for the event — will receive a new Firefly glow-in-the-dark toothbrush and a goody bag of gifts. The youngsters will also be entered in a raffle to win one of three Nano iPods.

Along with reducing damage to young teeth, the candy collection also will benefit U.S. troops.

Good habits taught when you’re young could go a long way—especially considering that 80 percent of U.S. adults have some sort of gum disease. Plus, if cavities are left untreated, they can lead to permanent damage including loss of teeth and gum disease, which has been linked to stroke and heart disease. Seriously, more candy, more problems.

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Image: flickr/ spundekas

Good news for those who fear the dentist’s chair: Australian Nathan Cochrane at the Cooperative Research Centre for Oral Health Sciences has created a liquid that can re-grow tooth enamel, effectively curing cavities while you sleep.

It sounds awesome, but it only works if you catch the cavities before they start—long before any sign of a hole appears in the tooth. The liquid works because of a protein known as casein phosphopeptide, which can be isolated from cow’s milk. When this substance is mixed with calcium, phosphate, and fluoride ions, it forms a special liquid that can attach and seep into parts of the tooth enamel that need strengthening, helping any damaged enamel to re-grow. A tray will be used to keep saliva out, which can prevent the liquid from hardening properly inside damaged teeth.

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