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Medicine Science

Plasma Jets Could Replace Dental Drills 131

Hugh Pickens writes "The first electric dental drill was patented in 1875; modern drills grind the diseased portions of teeth away at up to 500,000 rpm. But dentists have been seeking less invasive ways of wiping out stubborn, tooth-decaying bacteria. Now Live Science reports that bacteria-killing jets of plasma could soon replace the drills used to treat cavities in our teeth. Researchers recently demonstrated that a small, blowtorch-like device emitting a relatively cool beam of purple plasma could eliminate oral bacteria in cavities, leaving more tooth structure intact than a drill does. To test how well 'cold' plasma jets (about 100F or 38C) sterilize tooth material, researchers took slices of dentin from extracted human molars, doused them with bacteria, and torched them with the plasma jet. An inspection via a scanning electron microscope of the damage done to the germs shows bacterial remnants had holes in their cell walls. When the plasma jet fires, it charges oxygen in the surrounding air, creating highly reactive molecules that can break down the bacteria's defenses. Researchers believe the technique could be available to general dentistry in three to five years."
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Plasma Jets Could Replace Dental Drills

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  • by dushkin ( 965522 ) on Sunday February 07, 2010 @08:27AM (#31051978) Homepage

    "Researchers believe the technique could be available to general dentistry in three to five years."

    COME ON, guys, my appointment is on the 22nd. Hurry!

  • so i just need to manage no cavities for another 5 years. it's been 6 since i saw a dentist. i can do this. come on!
    • Re:right... (Score:5, Informative)

      by Eternauta3k ( 680157 ) on Sunday February 07, 2010 @08:40AM (#31052030) Homepage Journal
      For cavities' sake, get checked. I skipped going to the dentist for years because I'd never had cavities, until I went and the guy found 3 :/
      • Re:right... (Score:5, Informative)

        by laughing_badger ( 628416 ) on Sunday February 07, 2010 @08:51AM (#31052068) Homepage
        For oral cancers sake, get checked at least once per year. At that rate, they are usually treatable.
      • Re: (Score:2, Insightful)

        Dentists in the US sometimes lie for money. I remember when I went to one in Florida, and he said he had "found" a cavity and wanted to charge a ridiculous amount to fill it. Not even a week later, a relative of mine in New York checked my teeth (yes, she was a dentist) and said I didn't have any cavities.
        • Re:right... (Score:5, Interesting)

          by budgenator ( 254554 ) on Sunday February 07, 2010 @12:05PM (#31053048) Journal

          Different clinicians practice to different standards and use differing treatment standards and different diagnostic methods. A dentist using the older standard probe and X-ray technique will miss more, using new digital radiography and new diagnostic aids more will be found. Many small caries can remain sub-clinical for decades or even unmineralized and get smaller or they can grow explosively. Sometimes the "caries" are caused by physical traumas like abfraction [wikipedia.org] due to bruxism [wikipedia.org], clenching and other parafunctional habits. Unfortunately there can be differences based on economic considerations as well.

        • by spineboy ( 22918 ) on Sunday February 07, 2010 @01:25PM (#31053628) Journal

          I recently went after many years, and the dentist found three. I was a little suspicious, and asked the dentist about it. He said yes, due to advanced digital x-rays, cavities are spotted earlier. The more important fact was that he said with newer filling techniques and material, it allows them to fill smaller cavities. The older fillings didn't "take" that well in teeth, and so dentists had to let cavities grow largert, so they could fill them successfully. So the up to date, modern dentist will probably find these "mini-cavities" and fill them before it becomes a giant cavity.
          Why do this then? Well one of my older style fillings was in a tooth that was weak, which cracked in half, and I needed a root canal and crown. The newer mini-fillings will keep more of the tooth, preventing problems like that in the future.

          • Re: (Score:3, Informative)

            by alcourt ( 198386 )

            Just because they say there is a cavity doesn't mean there is one. A younger dentist insisted I had three cavities that needed filling. No x-rays, just based on the pressure test (where they push down on your teeth with a probe), where the dentist pushed down much harder than standards from several other dentists.

            I changed dentists. He used x-rays and the pressure test and concluded no cavities. I mentioned what the other dentist said and he said no, no evidence of even smaller cavities. Since I was a

            • My experience was basically almost exactly like this, except neither dentist used X-Rays; just the probe. I still don't have any cavities, and it's been four years since that dentist said I had a cavity. Thanks for backing me up alcourt :)
            • Ahh -that's the kicker.My dentist had a screen right next to the chair showing me where the carries were. Digital x-rays are quite nice, as the images can be blown up to show you where the problem lies. Mine was easy to spot.

              I concur - ask to see the images. If you're at all concerned, then get a second opinion. No one is holding you in that chair.

              • Digital x-rays are nothing more than a small sensor connected to a computer by USB. As a bonus, they use much less X-ray radiation than the old film.

                If your dentist isn't using this technology by now (mine has for almost 10 years), then you need to switch dentists. There's no reason to stick with someone who's too cheap or stubborn to get out of the dark ages of dentistry. Same goes for anyone using those horrible old mercury-filled fillings.

      • Pfft, that's nothing. My dentist tells me that I have soft enamel passed down from my parents, so I regularly developed cavities throughout late high school and college. One time, between my regular six-month visits, I managed to develop 5 cavities. The most frustrating thing for me was the fact that I managed to develop them despite regular brushing with prescription toothpaste, flossing, and rinsing with prescription mouthwash, all while abstaining entirely from non-diet soft drinks at the request of my d
    • Re:right... (Score:4, Informative)

      by deniable ( 76198 ) on Sunday February 07, 2010 @08:54AM (#31052088)
      I had my first fillings almost four years ago and the dentist had already stopped using drills. Mine were shallow so he used a mini sand-blaster. Mouth was full of grit after but better than the stories I've heard about drills. He said for deeper work they use a laser.
      • Re:right... (Score:5, Funny)

        by Dachannien ( 617929 ) on Sunday February 07, 2010 @09:17AM (#31052194)

        He said for deeper work they use a laser.

        That sounds awesome, but I'm a bit confused: how do they fit the whole shark inside your mouth?

      • The drills really aren't that bad, assuming that the dentist doesn't botch it. No new technology can be expected to solve poor technique or accidents.
        • Re:right... (Score:5, Interesting)

          by TeknoHog ( 164938 ) on Sunday February 07, 2010 @09:59AM (#31052412) Homepage Journal

          The drills really aren't that bad, assuming that the dentist doesn't botch it. No new technology can be expected to solve poor technique or accidents.

          Actually, the way I understood this is that plasma is used to disinfect the dentin, instead of mechanically drilling away the infected part. So there is less potential for mechanical damage as well. Some drilling is probably necessary to remove the mechanically decayed part, but there is less need to remove extra layers just in case.

          • Re:right... (Score:5, Informative)

            by aurispector ( 530273 ) on Sunday February 07, 2010 @11:06AM (#31052742)

            Looks like yet another solution looking for a problem. The point of the drilling is to remove infected dentin and leave healthy dentin intact. When teeth decay it's a process in which bacteria are demineralizing and destroying the hard structures of the tooth. Simply killing the bacteria is not sufficient to restore the damaged structures; the damaged structures themselves must be removed, along with any undamaged structures that have been undermined by decay. Additionally, if disinfection were the only goal the decay would still need to be exposed via drilling in order to effect disinfection. As much as people hate the drills, they also provide tactile feedback as to the location of decay. Hard tissue lasers are extremely expensive relative to the drills and provide no such feedback. Visual inspection is often insufficient to determine the quality of the dentin which is why we are always poking with those sharp little explorers. Another issue is being able to determine whether or not the bacteria have all been killed. Leaving infected dentin behind means the decay will simple continue from that point. Removing all of the softened, infected dentin is necessary to prevent recurrence of decay. Incidentally, traditional dental amalgam fillings (mercury, silver and tin) are inherently somewhat antibacterial. The metal tends to inhibit bacterial growth providing a small measure of protection to recurrence. However preventative measures like good daily diet and hygiene (e.g. cutting out the sugar and brushing/flossing) is still the best means of preserving your teeth.

            Other methods of disinfection have been tried and failed, hence "drill and fill" remains the most reliable method of restoration.

            • I am a laser service engineer. Hard and soft tissue lasers become more and more cheap over the years, you can get a 400mJ Erbium YAG laser for less than 30.000 USD. A lot of my customers (dentists) agree that laser will be quite in every dentist office in less than ten years, at least here in Europe. Plasma jets are however still on the blackboard.
          • Re:right... (Score:5, Informative)

            by Anonymous Coward on Sunday February 07, 2010 @11:09AM (#31052754)

            As a dentist, I can comment here with some degree of authority on the subject. If a tooth has cavitated, in other words, the surface has broken, the dentin part you speak of being disinfected is a mushy mess. Even if the plasma could "disinfect" this area, the tooth would be left with a spongy core, incapable of supporting the remaining hard structure of the tooth. One of the fundamental parts of preparing a tooth is to not leave any unsupported enamel. If "infected" dentin is left, albeit bacteria free, the chance for tooth fracture is great.

            I do think that this technology would work in early caries removal, such as shallow lesions. Often you don't know how deep a carious lesion will go until you open things up and start excavating decay out. At some point you will have to use some sort of mechanical process to scoop the decayed material out, either a hand instrument or a slower speed bur.

            Now if you are concerned about the trade-off between exposing the pulp (nerve) and needing a root canal, or leaving a thin layer of carious dentin, this plasma approach may be good. It has been shown in research that a small layer of decay left under the proper filling, can repair itself and if small enough no root canal therapy may be necessary. The plasma may help out in disinfecting this area and help out the repair process. But I digress...

        • My problem with the drill isn't so much the touch factor (vibration)...it's the secondary factors, like the smell and the noise. Those can't be addressed with technique on the part of the driller.

          • How about earplugs and noseplugs?
            • by beguyld ( 732494 )

              How about earplugs and noseplugs?

              Bone makes a very good conductor of sound vibrations right to your ear. Smell maybe, though you'll still taste it, which might be much of what is actually happening anyway.

              • You cannot taste if you cannot smell. I have gotten to the point where the dentist is actually pleasant, even when drilling and doing all manner of things in my mouth, because I don't resist it. Kind of a zen thing. If I explained it you would not get it. LOL
    • Re: (Score:1, Insightful)

      by Anonymous Coward

      This reminds of the following classic AI koan:

      ---

      In the days when Sussman was a novice, Minsky once came to him as he sat hacking at the PDP-6.

      "What are you doing?" asked Minsky.

      "I am training a randomly wired neural net to play Tic-Tac-Toe."

      "Why is the net wired randomly?" asked Minsky.

      "I do not want it to have any preconceptions of how to play."

      Minsky shut his eyes.

      "Why do you close your eyes?" Sussman asked his teacher.

      "So the room will be empty."

      At that moment, Sussman was enlightened.

  • Home use? (Score:5, Interesting)

    by MartinSchou ( 1360093 ) on Sunday February 07, 2010 @08:32AM (#31052000)

    Would this kind of device be useful in the bathroom? Probably not as a replacement for flossing or brushing, but fighting plaque build-ups in places you can't really get?

  • Hard coating? (Score:5, Interesting)

    by swb ( 14022 ) on Sunday February 07, 2010 @08:40AM (#31052034)

    I've always wondered why they haven't developed a hard coating for teeth that would prevent most cavities and why we don't have vaccination against caries and periodontal pathogens.

    It often seems like the basics of dentistry have changed little. There are newer materials for crowns and tooth-colored fillings, CNC machines and 3d modeling for crowns, but AFAIK going to the dentist is little different for me now than it was 40 years ago.

    I sometimes wonder if advances in preventive dentistry aren't limited by the structure and practice of dentistry itself. Plus, dentists being dentists, they have a built-in interest in high-quality preventive care (high-frequency flossing, rinses, brushing, etc) and thus themselves develop few of the chronic problems that plague the general public and thus don't devote resources to better passive preventive systems/technologies as they believe the ones available are "good enough".

    In a way it kind of reminds me of the problems non-technology people have with computers that technology people don't suffer from; these issues don't really get addressed within technology itself very aggressively because to the people who don't have these issues, they aren't considered serious problems or are considered side effects of other problems (general ignorance or lack of intelligence, etc).

    • Re:Hard coating? (Score:5, Informative)

      by vadim_t ( 324782 ) on Sunday February 07, 2010 @08:49AM (#31052060) Homepage

      It exists: Dental sealant [wikipedia.org]

      • Re:Hard coating? (Score:4, Interesting)

        by cntThnkofAname ( 1572875 ) on Sunday February 07, 2010 @09:13AM (#31052168)
        I have dental sealant, and it's no where near as good as natural enamel. I believe swb is getting at something that is better, that doesn't suffer from decay like enamel. The dental sealant that I have wears of every 3 to 4 years which results in mind numbing tingling sensation from exposed tooth nerve.
        • Re:Hard coating? (Score:4, Interesting)

          by CrimsonAvenger ( 580665 ) on Sunday February 07, 2010 @11:20AM (#31052800)

          I have dental sealant, and it's no where near as good as natural enamel.

          Last time I talked to a Dentist on a related subject, he told me that that's by design - better that your natural teeth wear on the sealant/crown/whatever than that the sealant/crown/whatever be hard enough to cause wear on your remaining natural enamel.

      • Re: (Score:1, Insightful)

        by Anonymous Coward

        It's nice in that it works to some degree. But it only protects the exposed part of the tooth.

        If you're a regular sugary bevarage drinker, all it takes is that one errant bit of popcorn, tortilla chips, or beef jerky between the teeth to let the soda do it's work below the gum line. If you're not a good enough flosser the effect happens much faster. You'll find yourself with the problem of an otherwise normal looking intact tooth - but with a cavity that forms just below the gumline. And who knows what gunk

        • by KDR_11k ( 778916 )

          I believe there have already been successes with stem cell-based teeth regrowing.

        • by Zerth ( 26112 )

          /. had an article [slashdot.org] about regrowing teeth in rodents. Alas, that is like 10 years off.

          I want glow-in-the dark teeth:)

    • Re: (Score:3, Insightful)

      by vadim_t ( 324782 )

      In a way it kind of reminds me of the problems non-technology people have with computers that technology people don't suffer from; these issues don't really get addressed within technology itself very aggressively because to the people who don't have these issues, they aren't considered serious problems or are considered side effects of other problems (general ignorance or lack of intelligence, etc).

      Actually, forgot to say, the solution to this exists, it's known as a "console", or a "cell phone". I mean pu

      • On general purpose machines such tactics are much less successful, because users actively fight such measures. At some point the user runs into a conflict between that they want to do something that the firewall/permissions/etc don't want to allow. And in such a case the security system is never seen as a good thing, and actively fought, disabled and worked around. Even if what the user wants to do is a seriously bad idea.

        You know, I just one a several-day fight against Windows 7 insisting that 60 Hz is go

        • by vadim_t ( 324782 )

          What I'm saying is, automation and safeguards are nice, but they should always be bypassable just by responding "yes" to a warning prompt.

          It's been tried, doesn't work well for a large amount of people. Ever seen how "normal people" use their computer? Warning pops up "Do you want to install the RootKit ActiveX from l33th4x0rs.com?". Typical user doesn't even read it, clicks OK, keeps on browsing as if nothing happened. If you ask them what they did and why they'll go "Huh?". Because that's what they normal

          • It's been tried, doesn't work well for a large amount of people. Ever seen how "normal people" use their computer? Warning pops up "Do you want to install the RootKit ActiveX from l33th4x0rs.com?". Typical user doesn't even read it, clicks OK, keeps on browsing as if nothing happened.

            I'm talking about making configuration changes, not browsing the web. A typical user isn't going to screw around with the config settings, so he isn't going to be harmed by being able to set things up the way he wants.

    • You have never had any serious dental work done. There are plenty of hi-tech advancements that didn't even exist 20 years ago.
      • by swb ( 14022 )

        Like what? I've had a root canal and 3 crowns and my wisdom teeth extracted in the last 2 years.

        I think some of the restorative technologies have gotten better (eg, implants, Cerac CNC-milled crowns) but the preventative technologies have not. Even stuff like wisdom tooth extraction doesn't seem very high tech.

        About the only thing I really appreciate is the ability to take the Halcion/Hydroxyazine/Nitrous cocktail before major work and blank out during the experience.

    • Re:Hard coating? (Score:5, Interesting)

      by Spatial ( 1235392 ) on Sunday February 07, 2010 @10:05AM (#31052442)

      why we don't have vaccination against caries

      Last I heard, one is currently in human trials. It works by replacing the bacteria responsible with a different strain that doesn't create lactic acid, and therefore doesn't cause caries.

      In tests on rats, it provided a permanent solution. Here's hoping it works out for us too.

      • A few questions remain, though: Are these new bacteria especially hardy? We still need to brush our teeth to avoid calculus buildup and bad breath and auch a replacement therapy isn't very useful if a few brushings kill off enough of them for traditional caries bacteria to take hold again.

        I expect the answer to be negative, though - they'll probably see no problem in you having to get a complete mouth disinfection and bacteria placement therapy once a year. Then again, if it's cheap enough (USA)/covered b
        • by LtGordon ( 1421725 ) on Sunday February 07, 2010 @12:05PM (#31053046)

          We still need to brush our teeth to avoid calculus buildup and bad breath

          Rationally speaking, brushing a minima of three times a day is integral to good oral hygeine.
          rimshot();

        • by Bert64 ( 520050 )

          Apparently they are genetically engineered to be dominant, and thus cause the naturally occurring bacteria to die off.

          I would love being able to brush less, i haven't found any toothpaste without a strong minty taste... A taste that wakes you up when you try to brush your teeth at night, and when you do it in the morning it leaves a strong taste in your mouth for hours that ruins any food/drink you try to consume.

          • A lot of toothpastes made for children are fruit-flavored, and Tom's of Maine (http://www.tomsofmaine.com) makes a few non-minty flavors. Also try your local natural foods store - they probably have some wacky flavors.

          • Tom's of Maine makes a strawberry flavored kid's toothpaste. It was a little weird using a non-minty toothpaste. You could also try making your own toothpaste and giving it whatever flavor you like.

    • by izomiac ( 815208 )
      That reminds me of a story that one of my organic chemistry professors told about the other. You see, he devised a compound that worked exactly like fluoride, but bound to teeth much more strongly. He'd verified that it worked as intended in his lab and sent a batch off to the medical school for animal testing. Well, a few weeks later he received a call about the experiment.

      "I have some good news and some bad news..."
      "Well, what's the good news?"
      "We've been feeding the rats a diet of pure sucrose and
  • Great! If this is a success... I might like going to the dentist :)
    Or maybe not..
  • by Trip6 ( 1184883 ) on Sunday February 07, 2010 @08:50AM (#31052066)

    It could unleash a whole evil dental underworld.

  • by HangingChad ( 677530 ) on Sunday February 07, 2010 @08:53AM (#31052086) Homepage

    ...researchers took slices of dentin from extracted human molars, doused them with bacteria, and torched them with the plasma jet.

    Do you ever wonder how they think up this stuff. Some researcher is sitting around drinking coffee thinking, "Hey, I wonder what would happen if you blasted a cavity with plasma?" How do you even think of questions like that without being stoned?

    Then I started wondering if I'm going to be hearing my dentist going, "Pew! Pew! Pew!"

    • by maxume ( 22995 )

      I would guess that you pretty much nailed it, except the guy was probably already obsessed with cavities and came across some information about low temperature plasma.

    • What makes you think they weren't stoned...?

      Speaking as a scientist, I think that's an untested hypothesis.

    • ...researchers took slices of dentin from extracted human molars, doused them with bacteria, and torched them with the plasma jet.

      Do you ever wonder how they think up this stuff. Some researcher is sitting around drinking coffee thinking, "Hey, I wonder what would happen if you blasted a cavity with plasma?" How do you even think of questions like that without being stoned?

      I just figure they get bored with tiny knives and needles and drills, and they want to take a tiny blowtorch to us now, those sadists ;-)

    • "How do you even think of questions like that without being stoned?"

      http://www.tsmhouston.com/images/plasma-cutting.jpg [tsmhouston.com]

    • by 10Neon ( 932006 )
      They probably read a paper on other medical applications of plasma jets, and thought, "hey, this could apply to my field".
    • "Hey, I wonder what would happen if you blasted a cavity with plasma?" How do you even think of questions like that without being stoned?

      I'm assuming the researcher in question happened to have a cool plasma torch and was looking for things to do with it. It's the same instinct that leads people who've learned a new programming language to reimplement some perfectly good existing piece of software for the umpteenth time just to use the language. If you could do dentistry with code, you can bet you'd see PyDrill and JDentures on Freshmeat.

  • by rdmiller3 ( 29465 ) on Sunday February 07, 2010 @09:10AM (#31052156) Journal

    The drill isn't just for killing the bacteria inside cavities (called "caries" by dentists). The drill is used to make an undercut hole large enough to get stuffed with filling material. In doing so, it removes not only the bacteria but also the food-material that the bacteria was growing on. A plasma jet won't do either of those things, so they would still need to use a drill.

    • by yanyan ( 302849 )

      Mod parent up. Not only that, drills are used for reshaping teeth, breaking up large impacted molars, chipping away dental cement, making waiting patients cringe, etc.

    • The drill is used to make an undercut hole large enough to get stuffed with filling material.

      I think the point is to kill the bacteria before they dissolve a hole big enough in your tooth to require filling. Then again I DNRTFA.
      The cleaning would proceed as usual.

      cavities (called "caries" by dentists).

      (And by the French.)

  • Not the only use (Score:5, Interesting)

    by codeguy007 ( 179016 ) on Sunday February 07, 2010 @09:24AM (#31052226)

    This isn't the only use. I watched an interview with the guy who invented the cool plasma. It can be used to sterilize hands as well. You know the sterilization chamber from Star Trek, the one you enter with your clothes off after coming back from a planet and get eradiated. Well you can do that too with cool plasma.

    • ...after coming back from a planet and get eradiated.

      I read that as 'eradicated'
      NOT GOOD!
    • Will it come with Jolene Blalock as an option?

    • I was about to comment on this. didn't /. have a story about this a while back, and one of the aplications was about dentistry among other things? anyone have a link to that original article?
  • 3-5 years? (Score:3, Funny)

    by gmuslera ( 3436 ) on Sunday February 07, 2010 @09:51AM (#31052360) Homepage Journal
    Make you hate when xkcd [xkcd.com] is right at something.
  • Where does the grounding clamp attach?

  • it charges oxygen in the surrounding air

    . Wait, is oxi-clean.. plasma?

  • Once again, plasma proves its technically superiority over LCD.
  • For there was never yet philosopher That could endure the toothache patiently.
  • An inspection via a scanning electron microscope of the damage done to the germs shows bacterial remnants had holes in their cell walls.

    I take from that, that it will also put holes it my cells’ walls.
    Do. Not. Want!

  • by ErikZ ( 55491 ) * on Sunday February 07, 2010 @02:19PM (#31053944)

    This adds a whole new layer of meaning when your Dentist goes "Whoops!"

  • After all, a full 70% of the top ten mysteries of the mind (according to them) actually had to do with the mind.

    In this little missive of theirs they make clear that we've all been mistaken thinking drills were for digging holes into materials like teeth, when all along they were intended for killing germs by digging holes into them.

    As for "creating highly reactive molecules that can break down the bacteria's defenses", you can buy a quart bottle of dental drills for a dollar or less. These drills go by the

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