MR. MARC FISHERFrom WAMU 88.5 at American University in Washington welcome to "The Kojo Nnamdi Show," connecting your community with the world. I'm Marc Fisher of The Washington Post sitting in for Kojo.

MR. MARC FISHERComing up this hour, we're talking about going to the dentist. The last time I went to the dentist, we chatted about the weather and office gossip and then he said, so do you want x-rays? And the answer was easy, no, I don't want x-rays. I never want x-rays. Why would I want x-rays? But then he asked do I need x-rays and I, of course, had no idea. Being a good and conscientious dentist, he said, well, I don't know either.

MR. MARC FISHERAnd so we went back and forth about what the latest science was and really what we came down to is the problem that's shot through all of medicine these days, which is the consumer has a lot more information, but also a lot more responsibility. and the question is how should consumers and parents decide about exposing yourself or your child to radiation, especially with new studies that link dental x-rays in childhood to brain tumors and cancer in adulthood.

MR. MARC FISHERAnd here to discuss this, Dr. Ricardo Perez is a pediatric dentist in full time private practice in Chevy Chase, Md. and joining us from Farmington, Conn. Dr. Alan Lurie is president of the American Academy of Oral and Maxillofacial Radiology. He also teaches at the Department of Oral Health at the University of Connecticut Dental School.

MR. MARC FISHERAnd Dr. Perez, these studies got a lot of attention in the press. And how seriously should people take this? Is this just one more of those scare studies we read about or does this change our behavior?

DR. RICARDO PEREZIt is great to be here. Thanks for having me. I think this educates everybody on having a candid discussion with your dentist regarding, in fact, the need of radiographs for dental care. Trust is critical when you bring your child to the dentist and any parent should be able to ask questions regarding what type of dental equipment is being used to expose the dental radiographs at the office.

DR. RICARDO PEREZAlso, parents should have the right to refuse dental radiographs if they feel that the child has had any other type of medical radiographs to an injury or a visit to the emergency room or anything like that. So have a conversation with your dentist. Find out what type of radiology equipment the dentist uses. Is it digital radiography, for example, which uses a considerably less amount of radiation time to expose the phosphor plates? So these are things that any dentist should be open-minded about for a parent and be able to discuss that.

FISHERAnd Dr. Alan Lurie, do you have any sort of easy answer that you give to people who are reading these new studies and saying, I don't know what to do here?

DR. ALAN LURIEHi Marc, it's a pleasure to be on National Public Radio. I think that the point of the patients being responsible and discussing these issues with their healthcare provider, whether it be a physician or a dentist, is very important. And I think an educated patient is a better patient. I think that the press that this paper received, unfortunately, is going to change people's behavior.

DR. ALAN LURIEI know that in my radiology clinic at the University of Connecticut, School of Dental Medicine, we have already had quite a few patients refuse radiographs that were needed to provide them with proper care. We try and discuss the need and the risk of not taking the radiograph versus the real risk of taking it, but some patients are so frightened by the way that this paper and cancer was covered that they simply can't be reasoned with. And it's really unfortunate because it sometimes puts their health in jeopardy.

FISHERWell what were the problems or issues with this research and in what way was the conclusion over-hyped, if it was?

LURIEOh, I think it was grossly over-hyped. The conclusion of the paper was that if you had certain types of dental radiographs -- and they were talking about the films that are placed inside your mouth and the Periapical and Bite-wing films and the films that rotate around your head, the panoramic films, that it increased your risk of getting meningioma, which is a benign brain tumor, the most common brain tumor in the United States today.

LURIEAnd the data that was presented in the paper is not really possible to be a cause and effect. And the authors did make the point that they weren't making radiation causing the tumor. They were simply showing that there was a relationship between having these radiographs at an earlier age and having these tumors. But the data in the tables was just nonsensical from a point of view of a radiation biologist.

FISHERDo you -- you can join our conversation with Dr. Ricardo Perez and Dr. Alan Lurie by calling 1-800-433-8850. Do you worry about dental x-rays when you bring your child to the dentist? Did you get x-rays as a child and now worry about your own health? And have you ever been thrown out of a dental practice because you refused an x-ray?

FISHERWe also want to get into the whole question of increasing tooth decay among young and very young children and changing parent attitudes toward baby teeth over the years. Do you let your little ones go without brushing, for example, and how has that worked out for you? Give us a call at 1-800-433-8850. You can email us at kojo@wamu.org or send us a tweet to @kojoshow. And Dr. Perez, do you share Dr. Lurie's skepticism about this study and what kind of impact have you seen it having on your patients?

PEREZYes, I do share his views on the study. I do believe that any dentist is obligated to practice the safest dentistry they can on their patients and therefore there are things that we should all do to minimize the frequent exposure to radiographs. However, there are many things that you can see in the mouth, but there are, unfortunately, other things that you cannot see. And when it comes to pediatric dentistry, there are really primarily two things.

PEREZOne is dental decay, many times you cannot see by just looking at teeth and when you see it already in the mouth, it's already kind of late. And then the other thing is malposition of teeth. So I do believe that dental radiographs are very important to come up with a proper diagnosis and recommendation to these parents of these children, but doing, or overdoing it may not be such a good thing.

FISHERAnd Dr. Lurie, have you altered at all your recommendations to patients to account either for the study or for simply the anxiety that parents and patients are feeling now about what they've been reading? Do you make adjustments in your recommendations to compensate?

LURIEOh absolutely not. I'm also a scientist and I've done a lot of federally-sponsored research on radiation-induction of cancer and radiation risk and I was a co-author of the "National Council on Radiation Protection Report on X-Ray Safety in Dentistry" that was published recently. And so my clinic, and I've been running this clinic for close to 40 years, has always used the fastest technology and the appropriate shielding and the appropriate selection of radiographs for the needs of the patient.

LURIESo we don't need to alter anything because we're already following the national and international guideline, which is called ALARA, that stands for As Low As Reasonably Attainable, and we have always practiced radiology in that manner. What has altered is the amount of time that we are needing to spend discussing this with patients. I have no problem at all with that. I think as I said before that an informed patient is a better patient and that patients need to take responsibility to partner in their care with their healthcare providers.

FISHERDr. Perez, as a pediatric dentist, you're dealing -- often you're kind of the first line of education for parents about their children and what needs to be done with their dental health. Are you seeing a shift over the years in that parents are becoming perhaps less cautious, less activist about bringing kids in at an early age?

PEREZUnfortunately, we have. We know that dental decay is on the rise in pre-school age children. We also know that the dental health of American children, adolescents and adults is better today than it was 20 years ago.

PEREZBut the problem with the little ones is that perhaps they are snacking too frequently and they're not getting their teeth properly brushed at home. And the single most important thing a parent can do in order to maintain their good dental health and prevent any dental disease is to brush their children's teeth so we strongly recommend that parents get involved and start this early on.

PEREZThe other thing that is important is that the American Academy of Pediatric Dentistry has now been recommending for several years and now has the backup of the American Dental Association and the American Academy of Pediatrics to bring the child to the dentist early and usually by one year of age.

FISHERAnd apparently, this decline in parents bringing their kids in or really pushing their kids to take care of their teeth has happened not just among the poor, but across the board, across the economic spectrum. Any theories on why there is this sort of increasingly lax attitude?

PEREZWell, we all have hectic lives and you probably know what it's like running a household at 7:30 at night with kids' homework and things happening at home. And very often, unfortunately, what happens is that kids just don't want their parents in their own mouth brushing their teeth and, you know, you cannot expect that a 3-year-old will do a very thorough job with their own dental hygiene. So start them early and we want the parent to supervise and to actually do it for the child.

PEREZAnd we can prevent this. We know that dental decay is a preventable disease. It's a progressive and infectious disease, but it is preventable and nothing will take the place of proper brushing at home.

FISHERAnd Dr. Lurie, is this a trend you're seeing nationwide with more cavities and more tooth decay among even pre-schoolers than we've seen over recent decades?

LURIEWell, that's a hard question for me to answer because the pediatric dentistry that's conducted in our dental school is at a different site. They're in downtown Hartford at the Connecticut Children's Medical Center and so I do not see a lot of imaging, a lot of children and images from children in our main dental school clinic.

LURIEI have a sense that kids are putting fermentable carbohydrates into their mouths more frequently, which is the worst thing they can do because every time they do that it makes their mouth more ascetic and...

FISHERWhat are fermentable carbohydrates, would that be?

LURIESugar, cokes, candy snack bars, anything with sugar in it. And every time they put that into their mouth, the mouth becomes more ascetic and that favors the growth of the bacteria that cause tooth decay. So it's a frequency issue, you know. If you nurse a coke along for two hours rather than just drink it down, you're going to have a bigger negative impact on the oral flora and you're going to get more decay.

FISHERAnd Dr. Perez, is there also a role being played here by the shift from drinking municipal water, which is fluoridated, to bottled water, which is not?

PEREZThat is a very good point. I don't know the answer of that because I do believe that kids today are still getting plenty of fluoride because there is fluoride in the toothpaste they use. There is fluoride in tap water, as you said, and even if they're drinking some type of bottled water, it's very likely that at brushing time or when they're visiting their grandparents or their neighbors or their friends, they're drinking tap water at the school, at the zoo so I don't think it's a fluoride deficiency issue. I think it's the constant grazing and exposure to different types of foods.

PEREZAnd unfortunately, the lack of brushing and, again, I do think that if we were to commit to starting early and get them used to a parent working on this, on their mouths, then the amount of decay that we will see will be reduced. And besides the sugar intake, it's also the starches, it's the, you know, we very often see two and three-yea- olds walking around and eating Goldfish and pretzels and crackers and animals crackers and this and that. So it's that constant grazing exposure what generates a consider amount of acid. And as the other doctor was saying, that this is eventually what manifests on dental decay.

FISHERLet's hear from Chino in Fairfax. Chino, you're on the air.

CHINOHi, yeah, it sounds like, at the moment, you're taking about the increase incidents of tooth decay but what made me call was the risk or, you know, the possible risks due to cancer later in life. I've never been worried about x-rays. I just assumed the dentist would get -- if it was needed, he'd -- that was the reason it was recommended. But as a Navy reservist, I get x-rays every year. I hope you can still hear me.

FISHERYes.

CHINOI get x-rays every year, just as -- so that the dentist can see that I have functioning teeth and that it's not going to put me at risk for immobilization or deployment because if it is and then I need to get it fixed by (word?) dentist. But the x-rays themselves don't serve a diagnostic, you know, function. There's no indicators to say "Oh, we need to get an x-ray." They just do it as a routine. So it makes me wonder, is this something that I should be worried about? And I'm a grown man and I've been doing this years. It didn't occur to me and, of course, that policy won't change anytime soon because of the study but it does make me wonder about that. And I don't want to just overly dismiss the connection that's made by the study.

FISHERSure. Well, let's see, Dr. Lurie, is once a year on a routine basis too frequent and -- especially if there's no condition that seems to call for an x-ray?

LURIEWell, there -- first of all, there is no such thing or should not be any such thing as a routine x-ray of any type for the general population. Radiographs are taken to serve a diet -- a diagnostic need. And in the case of somebody who could be sent in to harm's way, it's very important that you not be carrying an occult disease that has -- that is moving toward your bone that could compromise you severely in the field. So the requirements for military personnel, for pilots, for people who step into harm's way are more stringent and the recommended allowed radiation doses are higher than they are for the general population.

LURIEThat said, as a general population person, there is no routine. I'm 66 years old and I've had one full mouth series of x-rays in my life which was about 20 or 45 years ago. And I almost never have radiographs. I have all of my teeth, I have no periodontal disease, I have one restoration in my mouth. I see patients that come in who are 22 years old and they're missing 12 teeth, the bone holding their teeth is melting away, they've got carries all over the place. They need much more frequent radiographs, maybe more often than once a year until they're rehabilitated. There are other people who are taking medications that dry their mouth out.

LURIEFor example, people who are taking really strong antipsychotic drugs. It tends to block the action, the salivary glands. And so their mouth loses the capacity to buffer the acid and they become very, very, highly at risk for getting decay. And it can be decay that can amputate all the teeth in their mouth right off at the gum line.

FISHERAnd I'm...

LURIESo...

FISHERI'm really struck by your statement that you've only had one full set of x-rays in your life. I mean, I know a number of dentists who serve -- routinely say to people who've had no dental problems at all, every three years or every five years you ought to do this. Are they overdoing it?

LURIEIt depends on the patient. There's really no other correct answer to that question. Because each patient is different, their oral flora is different, their dental status is different, what they eat is different. And it's the responsibility of the dentist to assess each patient as an individual and to image them in the most appropriate way for what their lifestyle is and for what their oral status is.

FISHERWhen we come back after a short break, we'll get into how x-ray technology has changed over the last two decades. We'll continue our conversation about dentistry after this short break. You're listening to "The Kojo Nnamdi Show." I'm Marc Fisher, sitting in for Kojo.

FISHERWelcome back, I'm Marc Fisher of the Washington Post sitting in on "The Kojo Nnamdi Show." And we are talking with Dr. Ricardo Perez, a pediatric dentist in Chevy Chase, Md., and Dr. Alan Lurie, President of the American Academy of Oral and Maxillofacial Radiology at the University of Connecticut. He's a professor at the University of Connecticut School of Dental Medicine. And Dr. Perez, we have an email from Patton in Fairfax, Va., who's saying "One thing I hate about our (word?) ..."

LURIEExcuse me, Marc. Can I just jump in for just a moment?

FISHERSure.

LURIEThere's one thing I wanted to say to that reservist...

FISHERYes.

LURIE...that I forgot to say. And that is, he wanted to know if he should be worried. And I don't think he should be worried because the -- and we can get into this more later. But the radiation dose that he got is minuscule compared to the dose that he gets from natural background radiation annually.

FISHEROkay. That's a good point. We'll get more into that question of comparative bounce of radiation in a few minutes. But first I wanted to hear this email from Patton saying that one thing she hates about her children's dentist "is that they seem to be recommending unnecessary procedures to us, expensive ones that our insurance doesn't cover and I don't really trust the dentist anymore. For example, they always try to get us to do the fluoride rinse which I've heard is unnecessary. They explain that the ADA recommends it but does that always mean it is necessary?" So eroding trust in the dentist and confusion about insurance coverage are contributing factors of to perhaps not going to the dentist as frequently. Dr. Perez?

PEREZWell, that is a very unfortunate dentist-patient relationship and if there is a lack of trust from the parent, perhaps, she should consider bringing her kids to a different dentist. In regards to the specific recommendations by the dentist, that was what was recommended. I do believe in the benefits of fluoride in order to prevent dental decay and I do believe in the benefits of good dental health and prevented dental disease. So -- but that's what I will recommend.

FISHERBut are there -- and we see this in all fields of medicine, questions raised about the role that manufacturers of particular products play in both promoting their products to physicians and dentists but also to customers, patients. And this has come up in the case of this new x-ray technology that's being promoted as the latest, greatest technology, the 3-D x-rays that some websites call the future for dental specialists. Dr. Lurie, what are these 3-D x-rays and are they really a step forward for patients or is it simply a new profit center?

LURIEThe technical name for these machines is cone beam computed tomography or CBCT. And they appeared on the scene a little over a decade ago and have advanced rapidly in terms of the quality of the images they produce and in terms of reducing the dose to the patient through the mechanisms of the machine and through being able to reduce the size of the field that is exposed in the patient. They are a very significant advance in diagnosing certain types of disease in the mouth, extra root canals in the roots of teeth that need to have root canal treatment of fractures in the roots and the crowns of teeth which were all but impossible to diagnose before these instruments came about.

LURIEThe relationship of roots, of wisdom teeth of the nerve and the mandibles, sometimes they're wrapped around the nerve and with conventional imaging, you simply could not see that. And with the cone beam, you can see it quite easily. Children that have teeth buried in their pallets, impacted teeth, it was very difficult to understand exactly where they were and with the cone beam you can see precisely what they are so that you can plan your treatment much more efficaciously and then the patient benefits form that. On the other hand, like any other radiation based diagnostic tool, they can be overused.

FISHEROkay. And Dr. Perez, do you use this technology?

PEREZNo, I do not currently use this technology and I do not anticipate to be acquiring this technology in my office. I agree with Dr. Lurie that there is certain situations for children, for the use of this technology. But it is very specific and is very rare. My position of tooth being one of them when you want to rule out the relationship of a tooth that -- or a surgeon perhaps will need to remove in regard to an anatomical (word?) that do have to be very careful with -- when working on that specific area then a three dimensional view of this area is indicated.

PEREZBut if you were to ask me if the average eight-year-old patient were to need a three dimensional panoramic view of their mouth, I will say, absolutely not. Therefore I don't know many pediatric dentist in the country that use this technology at this point.

FISHERWe have an email from John who asked "At what age should a parent trust or allow a child to brush their own teeth?" And let's also bring in Tom in Alexandria who has a similar issue, Tom?

TOMHi, yeah, I'm enjoying your show. I have a son, he's 11 years old and, of course, I'm a great father and I tell him to brush his teeth every day and all that stuff, twice a day. And then he brushes it, like, five seconds, I'm done. And then I try to get him to brush more and he just goes off, "I'm done, I'm done, I'm done." And I'm tell him, you know, I don't want you to -- I want you to have good teeth and all that and I want him to have good habits when he moves out of the house later on. And also, wonder if you'd say, pretzels and sugar, I know, it's bad but how about some good ideas for him to eat? He does eat lots of fruits and vegetables too. And so, I want to (unintelligible) ...

FISHEROkay. Dr. Perez, what should Tom do about his child who brushes the teeth in 12 seconds?

PEREZTom, you're not alone. And at 11 years of age, of course, we want your son to be able to do a very good job with brushing his teeth but I just add, his spends a few seconds. So continue to supervise that. You know, we know that three, four, five year olds don't have good hand dexterity to do a very thorough job with brushing their teeth.

PEREZBut we should began to expect that by 8, 10 years of age, they can do it by themselves. In terms of the snacking, I don't have a problem with the snacks, I do that myself but it's, again, is the constant exposure to grazing all day long what could potentially be a problem. With an 11-year-old, also, is an orthodontic age and if your child were to be in braces, then you have to be even more conscientious about what they're putting in their mouth and how they are brushing their teeth off.

FISHERAnd as to John's question about, at what age should a parent trust a child to brush their own teeth unsupervised. Where would you call that line?

PEREZIt depends of what a great job you have been able to do. And is when the child has demonstrated to you or to your child's dentist that he or she are doing a very good job, you know. There is many of patients that come to the office and their teeth are perfectly clean. So those kids are doing a very good job, perhaps assisted by their parents. We hope that that is the case. Eight, 10 years of age is probably the right age.

FISHERHere's John in Fairfax with another question.

LURIEAnd excuse me, can I add one more thing to that brushing?

FISHERSure.

LURIEIs that electric toothbrushes are wonderful. And that's been shown in several studies. And you can get a lot more done in a lot less time if you have a problem using a manual toothbrush. And they're gentler on the soft tissues as well. So I recommend to all the patients that discuss this with me, using an electric toothbrush.

PEREZYeah, I agree with that. With electric toothbrushes, again, it does require some parental supervision, just to turn the power button on and expect that the toothbrush somehow is going to do the trick is not going to happen but yeah, they're very good.

FISHERJohn in Fairfax, you're on the air.

JOHNYes, I was calling concerning 15-year-olds gargling with Listerine. I'm concerned it's probably a bit -- it's alcohol strong and generally acidic. And I just had some concerns on that.

FISHERDr. Lurie, is Listerine a proper product for young teenagers to use?

LURIEI don't know.

FISHERDr. Perez...

LURIEI don't really have a good answer for that.

FISHEROkay.

LURIEBut...

PEREZI personally...

LURIE...what I can say is that if you're using a toothbrush properly, you don't need mouthwash at all.

FISHEROkay. Dr. Perez?

PEREZYes, I agree with that. And you, again, you cannot expect -- if you do use a mouthwash, that the mouthwash alone is going to do the job. So brushing, brushing, brushing. Now, as far as the safety of Listerine, you know, I will say it's okay for a 15-year-old to use it as long as there is some supervision. There is other types of mouthwashes that are alcohol free and therefore are safer for a young child to use.

FISHERAnother question about a product, an email from Malia (sp?) , she asks, "Do you think that gummy vitamins are contributing to the decline of kids dental health?" In other words, it's a product meant for one aspect of health having a deleterious impact on another aspect. Dr. Perez?

PEREZI don't know if any information regarding that. And, you know, vitamins are recommended and are -- I don't think they're harmful. And the chewable vitamins, I think are -- okay, again, is a matter of the frequent exposure to different types of foods, sugar foods, starches and the lack of brushing, what may be contributing to that because we see it across all social, economical barriers.

FISHERThere's a -- here's Peggy in Olney, Md. Peggy, you're on the air.

PEGGYThank you, I also have children so as a mother of the patients, the pediatric patients, I too was a pediatric patient and I think my mother made several mortgage payments for these guys when I was a kid. Now that I'm a parent, I've had situations where the dentist says "Oh, your daughter has an overbite, she needs these thousands of dollars worth of work and she has four cavities. And you have to get her molars covered with whatever this stuff is." I do feel more like a consumer then a patient and then I get a second opinion and then none of that is true. Where do I go for sound information?

FISHERDr. Perez?

PEREZThere are sources for you to look into. The American Academy of Pediatric Dentistry is a great resource. The American Dental Association and of course, again, you do have to develop some type of trust in relationship with the provider of dental care for your children. And in regards to your question about dental sealants, these are called pit and fissure sealants. This is a plastic coating that we apply on permanent teeth, primarily on the biting surfaces of the teeth where there is certain anatomy that allows these starches that we have been talking about to build up. So I personally do believe in the prevented benefit of sealing teeth. I do recommend it on permanent teeth and in certain situations, we apply it on primary teeth as well.

FISHERDr. Lurie, would you take the same approach?

LURIEYes.

FISHEROkay.

LURIEYes, I would.

FISHEROkay. We have a comment posted on our website by Newcastle, "Should those of us who grew up getting dental x-rays during the 1960s and '70s be more concerned than kids growing up in the '80s, '90s and beyond?" In other words, was the amount of radiation that we were exposed to back then so significantly higher that there should be some cause for concern, Dr. Lurie?

LURIEWell, that's a very good question. When I started working in 1973, at the health center, the average patient dose from a full mouth series which would be about 20 radiographs inside the mouth, was about a 100 times higher than it is today so the risk was commensurately higher. That said, the risk was still very small, and let me just give you a couple of numbers. The dose from a full mouth series then was approximately 20 rads, which would be about .002 gray, or .02 gray. So it was a lot higher than it is today because the full mouth series today would be about 400 microgray, which is two orders of magnitude lower.

FISHERAnd how does that compare with other sources of radiation in our lives, you know, being checked at the airport or something like that?

LURIEI think that the -- oh, the check at the airport is so small it's very difficult to measure it, and it's only superficial energy. It can't even get through the -- very far through the skin. I think that the benchmark dose that would mean the most to people is how much they receive annually from natural background radiation. That's not including cell phones, and smoke detectors, and even their own bodies which emit natural radioactivity at very low amounts. The background that you get one year every year living in the United States is 3,000 microsieverts. So it's a lot, lot bigger than any of these dental x-rays that we're talking about.

FISHEROkay. Here's Don in Alexandria. He's a former x-ray tech. Don?

PEREZMarc, if I may, I agree with everything that Dr. Lurie said, and I just want to reassure the audience that I know of no dentist that will recommend a full-series radiograph to a child. So we do not do a full series (word?) radiographs on kids. We take two very small films when we do, and we don't overdo it, and I do believe that pediatric dentists in the country and hopefully adult dentists don't tend to overdo it.

FISHEROkay. Don in Alexandria, it's your turn.

DONYeah, hi. Thanks for taking my call. I'm a former military Army x-ray tech, regular x-ray tech, not dental x-ray tech, and you know we would wear our dosimeters every day to work to make sure we weren't getting, you know, any radiation, but sometimes of course you would take your dosimeter off and you'd have to hold some patients, either, you know, a young child that wouldn't hold still or an elderly patient who couldn't stand for long, and while you wouldn't necessarily be in the central beam, sometimes your hands were or fingers, you were definitely close enough to get a lot of scatter radiation.

DONSo when I changed dentists recently, and I told him that I wasn't comfortable with getting dental x-rays, you know, twice a year during my regular dental checkup, he was real sympathetic. He was, you know, okay with that because I told him that I'm pretty close to receiving my lifetime permissible dose as calculated, you know, back then with the formulaic n minus 18 times, and I forgot the coefficient that you multiplied it by, and but -- and being your age of course, and when you're 20, 21 years old, you don't have a lot of, you know, x-rays to give.

DONSo he was really sympathetic. But I was wondering if that is a routine part of getting x-rays during your normal dental exam, and if that's the case and you don't need them, is there some reason to have them other than, you know, does it make money for a dentist's office?

FISHERDr. Lurie?

LURIEYeah. That's a very good question, and the -- keep in mind that the recommendations for allowable exposure to an occupationally exposed person are different than they are to a patients who's the member of the public. So that formulaic that was used, which is only used for occupationally-exposed people now, does not apply to patients, otherwise everybody would wearing dosimeters. The main risk that you were exposed to then was probably from your hands and from your skin.

LURIEI know I'm dosimeter-ed up every time that I'm working and I do some fluoroscopy work as well, so that's important to do that. That said, I'm very suspicious of any dentist who is recommending any type of radiographs twice a year. The only situations I can think of where that would be necessary is if you're following a patient that has rampant carious destruction, or an unusually aggressive form of periodontal disease, or is having massive amounts of root canal work that have to be followed, or if they've had oral cancer and they're being followed for a recurrence. They're all unusual and severe diseases, but there's no regular dental care that should involve any type of imaging twice a year.

FISHERYou can join our conversation about dentistry at 1-800-433-8850, and we'll continue our conversation and ask our guests what they do about patients who simply will never have an x-ray when we come back after this break. I'm Marc Fisher, and you're listening to "The Kojo Nnamdi Show."

FISHERWelcome back. I'm Marc Fisher of the Washington Post sitting in for Kojo Nnamdi, and we are talking with Dr. Alan Lurie, president of the American Academy of Oral and Maxillofacial Radiology, and Dr. Ricardo Perez. He's a pediatric dentist who practices in Chevy Chase, Md. And we have an email from Sue saying, "I'm only -- I'm 52 years old, have only had two extremely small cavities and no gum disease of any kind, and yet dentists require a full set of x-rays every year which I've had all my life." And she says she's not happy that she's now hearing that this probably should not have been done and, "It's news to me that this should have been considered on an individual basis." Dr. Lurie, how common do you think it is that people are being x-rayed too frequently and without proper cause?

LURIEWell, this is definitely an opinion, because it's pretty hard to get data on 150,000 dentists nationwide, but I think it's probably more common than it should be.

FISHERAnd is that because the dentists are ill informed, or trying to make more money, or what's their motivation?

LURIEOh, it's probably complex. On the one hand you've got the fear of litigation in a very litigious country, and people have been sued for missing disease because they either didn't take a radiograph, or the radiograph was of non-diagnostic quality, and so they're defending themselves. It's practicing defensive dentistry. There's defensive medicine as well. A second reason is that it is a very lucrative activity in a dental office because the dentist doesn't have to actually spend any of his or her own time acquiring and processing the radiograph. That can all be done by staff.

LURIEAnd so the profit margin on running the radiographs is very high. And then the third reason is that they may very well feel that they cannot adequately diagnose the patient without getting the radiograph which shows them things they cannot see with their eyes, and it's a combination of factors. It's not a simple answer.

FISHERDr. Perez?

PEREZI will add that I agree with that, and of course, I treat children, so I don't necessarily see or recommend what this caller has been exposed to, but I would strongly recommend to her that if in fact she has had two cavities in her entire life, and has no periodontal disease, and has a perfectly health dentitia, that she decline the taking of the radiographs next time she goes to the dentist. There's nothing we can do for the ones that have been done already, but moving forward she absolutely should not have a full series of radiographs.

LURIEI agree. I agree with that recommendation.

FISHERAnd at the other end of the spectrum, when you feel that x-rays are indicated, and you have patients who say, you know, I'm worried about radiation, I just don't want it, and they say year upon year upon year, how do you as a dentist deal with that? Does there come a point where you say, you know, I can't in good honesty treat you any longer?

PEREZAgain, I'm a pediatric dentist so it's different for me than it is perhaps for an adult dentist, but we simply document it and every parent I believe has the right to decline radiographs. They don't feel that it's necessary or if it's appropriate, or that the child's health history is such that they shouldn't have radiographs taken that specific year. So again, it is different for a kid than it is for an adult. We simply document it and we hope that this is one of those kids that will grow up caries free and will not have problems, but of course if a problem arises, then we deal with it, and a parent usually will agree that if there is an obvious sign of dental decay or some type of dental disease to have a radiograph taken, and we're talking about one or two films. We're not talking about, you know, 14 or 16 films.

FISHERHere's Noel in Washington D.C. You're on the air.

NOELHi, thanks for taking my call. I know you're talking about dentistry for children, but it really starts there and then it seems like it continues as you get into the adult phase where dentists -- maybe they don't do this as much now, but you basically get one every time you go in which is twice year, and my wife and I very consciously, quite a few years ago decided once a year maximum. But to bring this point home I think, when I was looking for new dentists, this was back in Tennessee maybe 25 years ago, I went to one and sat in his chair and told him basically my history and what I wanted to have done, and he started telling me about well, he wanted to give me an x-ray.

NOELAnd I said, well, I'd prefer not to do that at this point, can I defer it until the next time? He got very adversarial. He literally kicked me out of his office, and I think this goes back to maybe being afraid of, you know, any potential litigation, but all I was simply doing is asking about his equipment, how often he got it inspected, et cetera, et cetera. But he took it, you know, very adversarially, and I was out of there in about ten minutes, and he didn't charge me.

FISHERThat's interesting...

LURIEThat's a good thing that you got out of there. I don't think you want to be treated by somebody that behaves that way. I agree with that.

FISHERAbsolutely. There's an email from Jim in Silver Spring with a similar story. He says he recently left a dental practice because "the dentist wanted to take x-rays every cleaning. I thought this was excessive since no other treatment was ever necessary," he says. "He refused to clean my teeth if I would not accept the x-ray. So there's a lot of practice out there it seems that -- not up to the standard that you're proposing here.

PEREZThat is correct, and I agree with Dr. Lurie. I think in both of these situations, the patient was able to get out of that practice and move on, and hopefully they will find a dentist that will be very responsible before they make that decision of recommending radiographs of any kind, and the frequency of them.

LURIEYou know, the ADA has very extensive recommendations for the frequency of radiographs and the indications of them, and it's age-related and dental status related, and they publish them jointly with the Food and Drug Administration, and several members of our academy, the American Academy of Oral and Maxillofacial Radiology composed those standards. But the most, you know, unless there's an unusual circumstance like some of the ones I described earlier, the most frequent radiographs on that recommendation chart are about every three years, and sometimes it's a five-year frequency, and they don't even address really people like me where there's just not dental disease. We're just lucky.

FISHERRight. Here's Kathleen in Falls Church. You're on the air.

KATHLEENHello good doctors. I am calling, and my concern is, I've had a recent experience with a child of mine at a pediatric dentist, and when I pushed back and said, gee, you know, every 12 months? They said, well, if you're concerned, we're willing to push it back to 18 months. My children both have had, you know, a series of two and three cavities at a time. But on the other hand, as an adult I walk into a practice with a dentist that I like very much, I've had a long-term relationship with, he's really excellent, and he almost threw me out of his practice and refused to clean my teeth because I didn't want to have x-rays done.

KATHLEENI think he was wanting them done at least every two years, and I have a very, very good record of, you know, flossing and very little dental work that needs done, so my concern is, can't you set up some kind of more thoughtful information for us patients so that we can go into a dentist that we like very much who's pushing us in -- for more of the x-rays than we're comfortable with, and so we can better dialogue, that we can walk in and say, hey, here's a little card, and given my good health and my good dental history, shouldn't I be able to move this on to every five years.

FISHERThat's a great question. Dr. Lurie is there that patients can...

LURIEYeah. Oh, yes.

FISHER...be armed with?

LURIEAbsolutely. Go to the website of the American Dental Association and you can fairly easily track into recommendations for type and frequency of dental x-rays, and it has two pages of tables that give the patient age, the dental status, what they're in for, the recommended frequency for following particular types of conditions. It's all right there. It's also on our academies website. I don't -- I think that it's available to the public. I know the ADA's is, and in fact, I've got...

FISHERAnd we're linking to that on our website at kojoshow.org.

LURIEMm-hmm. Adapubs@adamail.org is, I think, the place you go to or maybe backtrack from there. Yeah. ADA...

FISHERAnd the -- go ahead.

PEREZThe reason why this pediatric dentist may have recommended radiographs once a year on their -- on her kids, it may have been because both of her kids she acknowledged have had some decay. But again, there's some recommendations, and they were published by the FDA and the ADA, and supported by organizations like the one Dr. Lurie is president of, or the American Academy of Pediatric Dentistry, and these are to help the individual practitioner make the best clinical decision on when and how to safely prescribe radiographs.

FISHERAnd very quickly, an email from Marie in Fairfax saying that she's heard some negative things about these 3D x-rays that her orthodontist has recommended. Very quickly, what questions should she be asking, Dr. Lurie?

LURIEYeah. This is really the big question right now is the use of cone beam CT for orthodontics, because when you're doing an orthodontic...

FISHERWe have just a few seconds.

LURIEOh, okay.

FISHERGive me one question she can ask.

LURIEThere is no published literature that shows any benefit to the patient from doing orthodontic treatment planning with cone beam versus the traditional way which is a lower dose.

FISHERDr. Alan Lurie, president of the American Academy of Oral and Maxillofacial Radiology. Dr. Ricardo Perez is a pediatric dentist in Chevy Chase, Md. I'm Marc Fisher. Thanks for joining us on "The Kojo Nnamdi Show."