Earned his DDS in 1971 from the University of California, San Francisco and continued post-graduate training at the Harvard Forsyth Training Center for Clinical Scholars in Oral Biology..Read More
Are Free Dental Cat-Scans Really Free And Other Related Questions
Table of Contents
- In what situation would I need a 3D CAT scan?
- How often do you use 3D CAT scans for dental treatment?
- How do 3D CAT scans affect overall cost of treatment?
- What is your personal opinion of 3D CAT scans?
- When was 3D CAT scan technology first introduced in dentistry?
- Was there any research about the potential risks behind 3D CAT scans in 2001?
- Have their been any developments on the dangers of 3D CAT scans recently?
- What is your opinion about this recommendation?
A general purpose of this website (adhp.com) is to offer information which will help you to more carefully evaluate many aspects of dental care being recommended to you especially that about dental implants. Obtaining knowledge as to the appropriateness of recommended care to you and what constitutes a good outcome for you is a primary personal responsibility of a diligent consumer of any sort. We have stressed in several sections of this website that a primary mantra of mine is “what’s not broken, should not be fixed.” That concept is applicable to treatment of teeth or placement of teeth, implants where teeth are absent or are to be imminently lost. We have argued to use caution when choosing dentists who use high technology devices or therapies as a marketing tool. We have emphasized that a service or device that costs more or is “new” is not necessarily better, nor may it have a better outcome, than those that may cost less or are more traditional. Your choosing to be treated at fancy offices with fancy equipment (although nice) does not guarantee favorable outcome. Finally, community standards of care should be practical, safe, and should not themselves create barriers to your access to any health care.
All of the above considerations are relevant to applications of three dimensional x-rays to dental implant and other dental care. Accordingly the history and benefit of 3-D cone beam scanning (CBCT) in the U.S., effects of marketing this approach, and relevant other issues such as legal considerations, safety, cost, and appropriateness of use of scanning will be discussed in the following paragraphs.
This section of our website is a little different than others herein. In particular it is more technical and somewhat philosophical and is addressed to dentists as well as to you the consumer. The bottom line (if you do not want to read thru the minutia) is only get 3-D scanned if you are advised with specificity of the need for this procedure and alternatives, if available. Do not be embarrassed to shop in an informed fashion for dentists or fees.
A primary situation where 3-D cone beam X-rays are beneficial and justified to facilitate treatment planning of dental implants is to allow for identification of the position of the nerve that goes through the lower jaw in relationship to its surrounding bone. This “mandibular nerve,” gives feeling to the lower lip and chin as well as the lower teeth and gums. When severe lower jaw bone loss has occurred, application of 3-D X-ray diagnosis is helpful to determine if or where there is room to place a dental implant, or implants, without injuring or even severing the nerve in its entirety.
If an implant must be placed closer than 2mm to the mandibular nerve (as represented in a conventional 2 dimensional x-ray), it is desirable to prescribe a 3-D scan of the area to receive the implant. Placement of a short wide implant in the chosen arch may obviate this need. In a condition called “severally atrophic mandible” (even in the area of front bone of the lower jaw where the nerve is absent), prescription of a 3-D scan is helpful to determine if too little bone remains for placement of implants where their presence might structurally alter the minimal bone remaining and therefore potentially give rise to spontaneous or “pathological” jaw fracture immediately or in the future. If the upper jaw, (sometimes in the frontal area and even the “back”) the amount bone remaining is so minimal that it is useful to use 3-D imagery to see if there actually is adequate width or height (of remaining bone) to place implants. Some times there is insufficient bone on either upper jaw sinus. A 3-D scan may determine if special bone grafts are necessary to augment the upper jaw sinus’ to create enough bone to support implants in these adverse circumstances.
Some implantologists use a form of 3-D imaging to automate part of implant placement. This may reduce human error in positioning implants to be placed. We do not use this technique because it adds great cost to treatment. In addition, this approach is generally unnecessary to improve outcome over employment of conventional imaging except possibly in complex situations. Unnecessary scans are not only potentially dangerous because of causing exposure to unnecessary radiation; they involve expenditure of funds which can be put to better use. In some cases the extra cost makes implant care itself unnecessarily unaffordable.
In more than three decades we have placed well over ten thousand dental implants. For diagnostic purposes we primarily use single periapical (traditional) two dimensional fast developing X-ray films. We currently see several dozen new patients each week for dental implant treatment planning. Our experience is that probably less than 1 in 20 new patients seeking dental implants really needs a three dimensional scan to receive a comprehensive treatment plan by adding essential information that cannot be derived from conventional x-rays. For those who need such diagnostic support, we utilize an excellent mobile 3-D cone beam scanning service that will come to my office, or to a patient’s home, to perform prescribed scans. This service, when necessary, costs about $190 to evaluate areas of interest in one jaw, or $230 for the same in both jaws.
When treatment planning includes recommendation of a 3-D scan, it is best to get a specific prescription from your dentist with regard to the area of interest to be irradiated. This allows for the scanning technician to use a minimal “field of view” (FOV) exposure of radiation on you to accomplish the prescription regarding implant placement. 3-D x-rays may inadvertently identify problems unrelated to implant placement outside the prescribed FOV. Patients are free to bring scans which may include anatomic sites outside the area of prescription to a radiology specialist for a more comprehensive assessment. In addition, patients always have the choice of requesting that their scans be performed as well as be reviewed by a board certified oral and maxillofacial radiologist specialist in that person’s designated facility. This is an elective decision that will certainly be much more expensive and less convenient than the service and fees I have quoted above.
Sometimes the costs of scans alone make implant placement unaffordable. Legal efforts to encumber 3-D scanning diagnosis with responsibility far from scoped intended purposes do not wisely protect the public. Rather this notion of routine comprehensive esoteric interpretation of scanning potential (as theoretically possible by specialist review) may actually lessen quality of care. This may occur by creating economic barriers to this service altogether as it becomes a cost intensive STANDARD OF CARE beyond it’s initial and intended purpose. Setting standards (legally enforceable rules) that mandate incurring costs beyond the intended scope of a scan prescription is defacto rationing of care by creating unnecessary cost to those who could afford my scan, or those of other dentists, but not that done by a certified radiologist at his or her facility where ostensibly asymptomatic extremely rare problems about which there is no complaint or symptoms and may be extremely rare to find might actually be noted. This notion of expanding scope of responsibilities to those who prescribe and then interpret 3-D scans for dental implants is essentially an “idealistic fishing trip” by those who may mean well, but in the end create unnecessary costs which will flow to radiologist specialists who may perform services that probably do not statistically improve in any significant manner any outcome. Ill conceived recommendations that drive up prices for those who need to be scanned based upon esoterically based legal conclusions is a significant part of why health care in general is so expensive. Often recommendations that are impractical and not evidence based are advocated by specialist groups or agencies in an ostensible effort to protect the public. What happens however is that business driven specialists render more expensive services which do not appreciably alter overall outcome? This has no effect on the wealthy who typically get over treated. However, in many cases the economic impact on those with less discretionary income to obtain treatment get undertreated and inadvertently and indirectly subsidize over treatment of the wealthy when both groups have insurance and the later are excluded as described.
Because of the discussion above, let me clarify our feelings toward 3-D scanning technology. We are definitely not against its appropriate use. What we are against is its indiscriminate (non-selective) use where there is not an absolute necessity and no alternative to obtain the information it can provide. It is common knowledge any x-ray rendered has a potential cumulative carcinogenic effect on the irradiated beneficiary. Therefore the preventive concept of ALARA (As Low as Reasonably Achievable) with respect to minimizing radiation should always be considered when exposing patients to any x-rays. If there is an essential requirement or treatment need, the potential risk of 3-D X-rays of the cone beam type is worth the benefit of this unique diagnostic aid. Certain oral pathological diagnosis may be 3-D assisted, as well as a complications arising from root canal therapy such as over fills and perforations. But these later needs are very infrequent, as are routine needs for 3-D scans in orthodontic diagnosis and treatment.
Those dentist’s who offer 3-D X-ray scans for free as an inducement for you go to their dental offices, are offering an unnecessary risk of cumulative uptake of “ionizing radiation” in most circumstances if those offices really scan every new patient as promised (or suggested to be promised) in advertisements. A “FREE SCAN” is not like giving an ordinary gift or discount; it usually comes with carcinogenic risk. Those of us who are older remember when free foot x-rays were given to induce people to shop at certain shoe stores. We received a number of those free exams, standing on top of an x-ray machine for extended periods of time with no precautions. “What a disaster!”
So, for safety reasons, the threshold for ordering 3-D imagery should be set very high by the prescribing dentist and all others who choose to make such recommendations. As will be thoroughly documented below, for economic and safety reasons, the scan prescription you receive should be very site specific.
With regard to historical perspective of 3-D images its first application was commercially introduced in clinical practice to the dental profession in 2001. “All these different cone-beam CT scanners came out to a world that was unprepared,” said Keith Horner, a professor of oral radiology at the University of Manchester in Great Britain. “They are just pushed out there by manufactures with the message that a 3-D image is always going to be better than a 2-D image, and that isn’t the case.” Some orthodontists now routinely use 3-D x-ray scan for treatment planning and placement anchor implants, although the former use is considered to be controversial as will be further explained. Many Endodontists (root canal specialists) have begun to use 3-D for treatment of complicated root canal situations as well as sophisticated microscopes. We believe reasonably priced implants and implant crowns may be a sensible alternative to receiving complex root canal diagnosed therapy which in the long term probably has an outcome that may not be good. Ultimately intricate treatment of teeth having complicated root canal needs (or having complications) will surely be followed with multiple expensive additional treatments. Educated consumers need to learn what is really best for them on a case by case basis with regard to cost and outcome. Those who undergo root canal therapy should know in advance that teeth with root canal fillings get brittle over time. Posts placed in these potentially brittle treated teeth (in my experience) commonly result in root fractures. Recurrent decay of crowned teeth is so prevalent that most insurance companies pay for crown or post replacement every 5 years. When choosing what is best for you to remember is that dental implants do not get brittle, and do not later need root canals or crown exposures due to recurrent decay that they (the implants) are not susceptible to. Most implants placed will last for life and in some cases (my office) may actually on completion cost less than the scope of traditional endodontic and prosthetic treatments collectively necessary to complete restoration of teeth needing root canals, etc.
Because of the rapid rise of 3-D technology, concerns and details of its safe use appear to have not kept pace with the distribution and marketing of 3-D scanning devices. According to a November 23, 2010 NY Times article by Bogdonavich and McGinty "The cone beam's popularity has been fueled in part by misinformation about its safety and efficacy, some of it coming from dentists paid or sponsored by manufacturers, to give speeches, seminars and continuing education classes, as well as by industry-sponsored magazines and conferences."2 In another article by Bogdonavich, he states “Promoters and marketing of 3-D imagery assert its use is “a safe way for orthodontists and oral surgeons to work with more precision and to identify problems that otherwise might go unnoticed.” Some marketers increase dentist’s interest in the 3-D technology by holding drawings for free cone-beam CT scanners and other gifts. A Washington State orthodontist, who gave an online lecture, sponsored by Imaging Sciences International, offers dentists coupons for free scans of their patients as a way to build orthodontic referrals to him.
The positions of the promoters cited above are not evidence based and imply routine use of 3-D scanning is not only ok, but desirable! We cannot find a referred scientific article that evaluates risk vs. benefit with appropriate scientific precision to support the conclusions of promoters including dentist promoters. In an article published in the Oral Health Journal.com, of June 2007 author Martin Bourgeois, stated that “an increasing number of clinicians have now incorporated Cone Beam CT into their requests when referring patients for pre-treatment imaging.3” The implication of this statement is that referrals for 3-D scans are made routinely and indiscriminately with no identifiable threshold for safety consideration or risk benefit analysis. It is, furthermore, noteworthy to me that even some dental insurance companies, according to dentists attending risk management conferences, has also unwisely promoted routine 3-D scanning as a general standard of care especially for “new implantologists” (personal communication with James Wong, D.D.S.).
Further cautionary advise again comes from the “Times article” which reports that the popularity of cone beam technology use “has been fueled in part by misinformation about its safety and efficacy.” Imaging Sciences International, a scanner manufacturer, underwrote a Journal of the American Dental Association (JADA) issue, devoted significantly to cone-beam technology. That October, 2010 JADA issue, routinely sent to 150,000 dentists, included a favorable article written by Dr. James Mah who incorrectly in his JADA published article equated the radiation emitted by a cone-beam CT scan with that emitted by an airport scan.
In an online lecture in 2010 (also sponsored by Imaging Sciences) titled, "Why Dentists Can’t Wait for Cone-Beam CT”. Dr. Mah once more played down radiation health concerns by again advising that, “a cone-beam scan produces no more radiation than a whole-body scan at the airport.” Formal opposition to Dr. Mah’s advice comes from Dr. David Brenner, who directs the Center for Radiological Research at Columbia University Medical Center. Dr. Bremmer says, “In fact, cone-beam scanners can be several hundred times as powerful as a normal x-rays.” Similarly, Dr. Allan Farman, president of the American Academy of Oral and Maxillofacial Radiology (AAOMR), has the following concerns. "They (dentists) need to be aware that, even if they are told at a meeting that a cone-beam CT scan is equal in radiation dose to a single airport x-ray or ultrasound scan, it is three orders of magnitude (one thousand times) wrong."
Stuart C. White, DDS, PhD, a professor at the University of California, Los Angeles School of Dentistry and Chairman of the school's oral radiology section, also challenges Dr. Mah’s advice as follows: "Many orthodontic patients can seemingly be treated perfectly well without cone-beam CT examinations (and have been for many decades), although some patients certainly benefit -- hence the need for guidelines to identify those patients likely to benefit and those likely not to benefit.1" Dr. White also states “So let me ask a question to the mother of a prospective orthodontic patient. Would you like me to use a tool that is entirely safe, a camera, to record the position of your child’s teeth, or another method that may rarely cause cancer so that we can save time?”
Another disturbing source of advice (again according to the New York Times article) is rendered by California lawyer, Arthur W. Curley. He has allegedly suggested that dentists might even face legal liability for not using 3-D imaging. Author Bogdanich discloses in his New York Times article that “Mr. Curley, along with (others), share more than their enthusiasm. They have all received speaking fees from Imaging Sciences.” When there are conflicts of interest by those rendering opinions, the conflicts ought to be disclosed.
Prominent dentist/attorney Edwin Zinman co-wrote a comprehensive article about legal considerations related to CT scans with Dr. White (cited above). They argue tentatively about the benefit or appropriateness of scanning for all implants placed. The article stops short of arguing for selectivity in use of scans for implants seeming not to want to offend other attorneys or dental radiology specialists and citing but not rejecting or arguing against a 2000 position statement by the American Academy of Oral & Maxillofacial Radiologists cited below . That position statement suggested that “cross-sectional imagery (which would include 3-D scans) should be performed for all implants,” presumably by some of their member specialists. I cannot be diplomatic about responding to this money generating, unsafe, non-evidence based, suggestion promoting over specialization in an over specialized profession. Co-author Dr. Stuart White (who I also greatly respect) seems to have lost the sentiment so vigorously put forth in arguing against routine ortho scans (as cited in the above paragraph) when it comes to routine dental implant scans.
Simply stated, we believe this recommendation cited above is a ridiculous, self-serving, and potentially dangerous position that should be expunged from scientific literature and apologized for! Those who have the authority and responsibility to set or effect standards of care should be very careful that broad interpretation of their opinions do not end up making impractical, expensive or even unsafe standards that become, at best, significant financial obstacles to care, and at worse, cumulatively dangerous. It is very important to distinguish between theoretical idealism and practical safe recommendations. Sometimes opinions are legally correct, but they are so adverse to overall outcome that they themselves approach a threshold of at least moral negligence and intellectual arrogance. Our profession is already hopelessly over specialized. Legal metaphoric coercion in the form of promoting irresponsible poorly thought out standards over evidence based only aggravates this problem, wastes consumers’ money creating unnecessary economic barriers to care for some and simultaneously overt treatment of others who will afford to do what ever they are told.
More consistent with my advice, a sobering, admirable, 2010 joint position statement by endodontist and oral surgeon societies noted that “CBCT must not be used routinely for endodontic diagnosis or for screening purposes in the absence of clinical signs and symptoms. The patient’s history and clinical examination must justify the use of CBCT by demonstrating that the benefits to the patient outweigh the potential risks. Clinicians should use CBCT only when the need for imaging cannot be answered adequately by lower dose conventional dental radiography or alternate imaging modalities.6” The joint statement also wisely advises “Limited field of view CBCT systems can provide images of several teeth from approximately the same radiation dose as two “regular” radiographs." Even though these official precautions and admonitions are very fair and clear about what should be the “gold standard” or legal standard of care, technology in health business in general, (not only in dentistry), is too often and too significantly market driven. (See cheap vs. expensive implant section of this website and Niznick vs. Nobelpharma on the internet).
Other forces promote over utilization of 3-D high technology include aggressive positioning by “upscale” avant-garde so called “spa” dentists. These dentists are driven by how they choose to promote or market themselves to purchase high tech machinery like 3-D scanners to foster and maintain their image and business model. There are whole journals, newsletters and quasi-professional scientific sessions constantly and ubiquitously dedicated to promoting high technology devices and treatment strategies. We believe the owners of scanning machines and other “high tech devices” drive their clients to pay too much, to get over treated, and in the case of 3-D applications take unnecessary risks. Once a dentist buys a 3-D scanning device (for $80,000 - $250,000) there is an inevitable mental paradigm shift justifying more and more use of this technology. This in turn results in more cost to patients than conventional methods, causing, (unfortunately), more unnecessary risks to that treated population as well. We guess it is all right when high technology devices such as intra oral cameras are used almost exclusively to sell dentistry. These cameras identify small defects in tooth restorations that became the basis for what dentistry does 75% of the time. Restorative dentists replace restoration done before (personal communication Dr. Max Schoen). Retreating someone else’s older work. We also suppose it is also all right when high technology “micro-surgical” microscopes are over used as compared to conventional approaches which have traditionally had good outcomes without the marketing appeal. Some root canal therapy microscope assisted may be better, but certainly not all root canals need to be done in this fashion as we have been told by one attorney/patient. Even periodontists are using new high tech high powered microscopes to assist deep cleaning. The new field of periodontal microsurgery is also microscope driven. We heard one famous periodontist say he has a microscope in every operatory, and uses them all the time. It may even be ok to routinely use lasers for periodontal surgery and incorrectly position this technique as new and better than traditional means to treat gum disease and tooth decay when application of this technology is usually just more expensive while delivering essentially the same outcomes as conventional care. We even guess it is all right that our dental literature is replete with pseudo scientific articles which are offered as evidence based foundations for the claims of marketing of expensive so called advanced dental technology. But when dentists start irradiating people unnecessarily for marketing purposes to pay off high tech equipment loans and make more money, we think the line of proprietary has been “crossed,” even when clever rationalizations and aggressive marketing of that technology is promoted as well documented by the New York Times series on that problem. Thank goodness for the New York Times and their reporters Bogdonavich and McGinty. It is hard for the profession to police itself when politics and marketing forces are formidable and peer review at best seems weak.
A final piece of the 3-D story therefore relates to regulation of 3-D scanning technology. According to another New York Times article regulators are just now recognizing how ill equipped they are to oversee this new technology. “There is not a lot of radiation exposure data out there,” said Jerry Hensley, a state radiation protection official in California. While protocols and guidelines exist for other types of imaging, Mr. Hensley said, “Cone Beams are off in their own land right now.”
Because of all the above information, my general contentions about cone beam assisted dental diagnosis include the following. With regard to 3-D assisted root canal therapy, a cost versus benefit analysis should be considered by every patient before commencing with that type of care. Choosing dental implant restoration versus complex restoration of a tooth or teeth with root canals, then posts, and often crown exposing periodontal surgery before you even get to the crown is to me a “no-brainer” kind of choice (for the complete implant approach and only get scanned if absolutely necessary). The same approach should be embraced by every patient who gets a recommendation to have routine 3-D scans for any reason, especially orthodontics. The House of Delegates of the American Association of Orthodontists adopted a resolution that states: “RESOLVED, that the AAO recognizes that while there may be clinical situations where a cone-beam computed tomography (CBCT) radiograph may be of value, the use of such technology is not routinely required for orthodontic radiography.” (American Association of Orthodontists, e-bulletin 05-06-10). 3-D cat-scans are not routinely needed for dental implants either.
We suggest that all prospective dental patients should beware of dental offices which induce, or glamorize prospective patients with, high technology 3-D imaging devices for free or any cost when those devices are recommended to NOT be used routinely. If an office has spent a lot of money to purchase a 3-D X-ray scanning machine, you can bet that office wants to use that device or similar high tech devices as much as possible to get them paid off. “Physicians who own their own medical CT facility are 5-7 times more likely to order CT scans than those who refer to outside facilities.” Dentists are probably no better or no worse than physicians with regard to this observation. If you are offered a free 3-D dental scan or sent out for one at any cost, make sure you really need it and that you are getting this service at a competitive cost for the right reason and only in the area that needs to be irradiated, if possible. Be careful about getting a scan at a referring dentist’s office by a machine they may own as opposed to obtaining that service from a professional facility of some sort dedicated exclusives to preforming radiological scanning services. Professional services probably have the most up to date equipment and their technicians are most likely best trained in radiographic safety protocol. If you want to go to a specialists lab and have a oral maxillofacial radiologist read and perform your scan, this is also ok if cost makes no difference to you or there is a very specific need to go to that specialist. Ask the referring or diagnosing dentist what are the risks or downsides for you not having a 3-D dental scan. Ask what reasons if any exist that you should you have the scan done by a specialist? You may be able to determine on your own if the costs and risks are justified and that the procedure, and who performs it will provide a satisfactory outcome for your potential dental implant care. Learn about special considerations that must be made in planning for that care that requires a scan. Ask why traditional x-ray techniques are not adequate to obtain a good outcome and whether your dentist believes he or she is competent to diagnose the specific prescribed scan themselves. If you are uncertain of the answers to the questions we have posed, ask for explanations to be given in writing and get another opinion or opinions about your concerns.
*** Rough Draft As Of January 17, 2011 ***
Adult Effective Dose for Various Diagnostic Radiology Procedures
|Examination||Average Effective Dose (mSv)||Values Reported in Literature (mSv)|
|Dental Intraoral radiography (bitewing)||0.005||0.0002-0.010|
|Dental Panoramic radiography||0.01||0.007-0.090|
|Posteroanterior study of chest||0.02||0.007-0.050|
|Upper gastrointestinal series||6*||1.5-12|
* Includes fluoroscopy
Values of effective dose presented here are representative, and actual values will vary on the basis of a number of factors discussed in the source article. Source: Mettler FA Jr, Huda W, et al. Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology 248(1):254-263, 2008. Available at: http://radiology.rsna.org/content/248/1/254.long. Accessed 1 May 2012.