"I have yet to see any problem, however complicated, which, when looked at in the right way, did not become still more complicated." This statement by Poul Anderson begins D. H. Meadows's book entitled Thinking in Systems.¹ The observation is relevant to a sometimes contentious conversation concerning the delivery of oral healthcare services in the United States. The discussion crystallizes around plans to introduce midlevel providers—dental therapists—into oral health-care practice. The intent is to make dental care available to people who either cannot afford it or who live in places where dental care is unavailable. Because dentists have disproportionately distributed themselves within affluent suburban communities rather than less affluent rural and central urban communities, circumstances typically conspire to make dental care neither available nor affordable to those most in need.

Dental Therapists: "Who Are These People?"

Neither the scope of practice nor the education of dental therapists has yet been fully defined. Many models have been proposed both domestically and abroad. However, the one thing that everyone can agree on—the very thing that virtually defines the dental therapist—is that procedures that used to be done exclusively by dentists are proposed to be done by non-dentists. Thus the exact scope of practice, level of supervision, and required education all remain open questions, depending on the specific model under consideration. The education of dental therapists might be as little as two years beyond high school; two years within a baccalaureate-level college degree; two years within a specialized master's-level degree; or incorporated into an advanced level dental hygienist program. But even when these logistical issues are resolved, introducing this new category of dental practitioner into the existing network of dental care delivery will probably be more complicated than what is anticipated by either ardent advocates or vociferous opponents.

To move the conversation forward, I suggest stipulating three assertions as unequivocally true:

1. There is a significant problem with access to dental care in the United States;
2. Children dying of dental disease because of a lack of care is utterly repugnant and unacceptable; and
3. Even if a two-tier system of dental care arises, the premise that some care is better than no care is irrefutable.

I consider all three self-evident, but the first deserves elaboration: Is there really an access to care problem? The evidence is compelling but circumstantial. The price for dental treatment has increased almost threefold (corrected for inflation) since 1947, and more than doubled since 1980, all at a time when the real cost of durable goods has declined. Dentists' incomes have outpaced inflation nearly threefold since 1990. Fewer dentists graduated in 2009 than in 1980 while, over the same period, the population of the country has increased by 78 million. For me, this evidence is dispositive: conditions are right for an access to care problem.

I am also prepared to concede three other points, though I admit that they are arguable:

4. Well-designed studies relying on impartial performance measures will demonstrate no difference in the technical quality of service delivered by dental therapists and practicing dentists;
5. Dental therapists initially practicing under the supervision of licensed dentists will not evolve over time into independent practitioners who will compete with dentists through free-standing parallel dental therapy practices; and
6. Patients-both adults and children-of every socioeconomic stratum will find care delivered by dental therapists to be entirely acceptable.

Whenever comparisons have been made in the quality of dental procedures performed by dental therapy students and dental students or between dental therapists and dentists, no difference is discerned. As dental therapy is expanded as a discipline, more studies will be conducted and will probably yield the same result. Should this surprise anyone? If a key difference in the education of dental therapists and dentists is the length of education, it's worth asking exactly how much time is spent learning the purely technical aspects of dental procedures. The difference between the two training programs might not be all that much. When learning how to place a class II restoration, does it really matter that the dental student studied the Iliad versus the Odyssey in college? Does a background in organic chemistry or knowledge of pharmacokinetics make a difference technically? Actually, I do think breadth of education is vitally important for a doctor—but less important for a technician. My point is that a more sophisticated background in the sciences and humanities will not be discernable in studies intentionally designed to assess purely technical outcomes. Why should they?

My prediction that dental therapists will not evolve over time into independent and competing dental therapy practices—at least not on a large scale—despite some pressure to do so is based on the premise that it's already hard enough for graduating dentists to make the kind of investment needed to establish a practice. On average it now takes about 12 years before 95% of dentists secure an equity position as sole proprietor or partner in a dental practice. Overwhelmingly, dental graduates are people whose exclusive professional ambition from the outset has been to own a dental practice. Even before beginning their dental education, dental students have the entrepreneurial disposition that led them to secure the loans needed to attend dental school and to project the adequacy of their return on investment. Dental therapy students are more likely to enter the field with the expectation of becoming employees. In fact, the entire premise of introducing this category of practitioner is that they will work in public sector clinics.

From the employment perspective, dental therapists will resemble pharmacists more than they do dentists. As a field, pharmacy is big business; i.e., it has become entirely corporatized. Unlike 50 years ago, no one seeks admission to pharmacy school with the expectation of owning their own pharmacy. Pharmacists are, prudently, risk averse when it comes to making a major and uncertain financial investment in a private pharmacy that cannot compete with the major chains. Over time, pharmacy has become less attractive to the entrepreneurial-minded and more attractive to those seeking employment in a retail pharmacy chain or institution. In other words, the field now appeals to a different demographic. It will be the same with dental therapists. Even in the emergent nurse practitioner (NP) field, the focus seems to be on generating greater opportunities for employment rather than direct proprietorship.

Dental therapists seem even less likely than denturists to establish private practices inasmuch as the latter emerge from the dental technology business, an extant and entrepreneurial cottage industry.

Regarding patients' acceptance of dental therapist services, the matter resides entirely within the hands of practicing dentists. Should dental therapists find employment in private dental practices, dentists will gravitate toward not giving patients a choice over whether they will be treated by the practice's dentist or its dental therapists—precisely the way they don't give patients a choice in being treated by dental hygienists or by expanded function dental assistants. Patients, generally, both like and trust their dentists. When the dentist steps out of the operatory and the dental therapist steps into it, patients will have no objection because, implicitly, the dentist has already given the okay. Dentists for whom it's not okay will simply not hire dental therapists.

Is Anything Left?

Given all these concessions, is there anything left to dispute? There is. And perhaps it is the most important question of all: Will the introduction of dental therapists as midlevel dental providers in the United States actually improve access to care? This point is central inasmuch as the entire dental therapist movement is predicated exclusively on the premise that it will. If this turns out to be wrong, then the rationale for the whole enterprise fizzles. In other words, while improved access to care is one possible outcome, it is naïve to think that this is the only conceivable result. Alternative scenarios are easily envisaged—perhaps even more likely—in which access to care is not improved, especially when taking into consideration (a) the existing market-driven economic infrastructure into which dental therapists would be introduced; (b) a lack of financial means or political will within federal, state, and local governments to sustain the kind of large-scale investment in delivery systems that would be needed to make the dental therapist model a success in caring for the underserved over the long-term; and (c) greater consistency and astuteness within the corporate sector for furthering long-term corporate interests by application of financial resources and exertion of political influence.

In other words, rather than dental therapists finding employment in community clinic settings, schools, and other community-oriented facilities, a setting is easily imagined in which these new categories of practitioners are hijacked—at considerably better pay—into a fully corporatized model of dental care, one unlikely to be attentive to the needs of the underserved; or, if congenial to those needs, only incidentally so. Again, pharmacy might be the model for how this scenario could materialize: Gradual consolidation of individually-owned practices; an increase in start-up costs which would mean that even fully-qualified dentists would find it harder to swing the loans needed to open or buy into a practice; followed by expansion of major retail corporations into dental care delivery services when profitability rises as labor costs provided by dental therapists decline. There is ample evidence that such an outcome is entirely conceivable.

In the 1960s both Sears and Revco (a drugstore chain since incorporated into CVS) offered dental services. Both programs were eventually phased out. It's easy to understand why: from the corporate perspective, dentists cost too much so the profit margin is too small. From the dentist's perspective, the pay is too low. The corporation supplies staff and facilities, but doesn't really provide anything the dentist can't secure on his or her own. If the dentist is willing to accept the financial risk of proprietorship, the return on the dentist's labor is much higher.

The Access/Cost Dilemma

Currently, some key stakeholders seem to support the introduction of dental therapists. Those stakeholders are immensely influential because they include not only public health dentists and many educators, legislators, the media, corporations, and dental hygienists, but also the many patients who are currently unable to secure affordable dental care. In short, a large block of the public agrees in principle with the dental therapist movement, or would if they directed their attention to it. This makes it relatively easy for promoters of the movement to capture the narrative. The means by which these stakeholders exert influence is powerful, driven by economics, demographics, public relations, and public policy. However, as dental therapists enter the workforce, the interests of these stakeholders begin to diverge.

For instance, is the intent to improve access to care or to maintain the current inadequate access to care but at a lower cost? This question differentiates the interests of the public health sector from the governmental sector. To improve access to care would mean that increased funding of community-based and school-based clinics would be required—the primary employment sites for dental therapists. But this will increase costs, not decrease them. At present, there is little evidence that federal, state or local governments are looking to spend more on oral health care. On the contrary, government seeks to spend less. Given the choice of staffing a community clinic with two dentists and four dental therapists or one dentist and five dental therapists, the second alternative would be cheaper. If about the same number of patients could be treated, government will gradually gravitate to the cost-saving option. The problem is that this will not improve access to care. It will only decrease the cost of inadequate access.

Will dental therapists function only within school or community based clinics? Among the models proposed, some include private practice options. In this arrangement, therapists would work within dentists' private offices treating both underserved patients and private paying patients—50% of the dental therapist's practice (not the office's) would qualify as underserved. The guarantor assuring that the private payer mix doesn't creep upward to the financial benefit of the therapist and the office will be a legislative mandate. The problem is that legislative mandates are amended by the stroke of a pen—particularly as pressure begins to be exerted on elected representatives from predictable quarters, including from employer dentists, as well as from large corporate dental service providers, and from dental therapists themselves.

When dental therapists are offered more competitive salaries from the private sector—either in dental offices or corporatized dental operations—the effect will be to draw these individuals away from the intended community-based and school-based clinics in underserved areas.

The Fatal Embrace

The impact of introducing dental therapists into the highly privatized model of dental care in the United States is simply unpredictable. Will the U.S. experience replicate that of other nations? The key determinant of success will be how these new practitioners are embraced by the economic system into which they are introduced. The verisimilitude of populations, economies, and health care systems is probably more important in attempting such extrapolation than are the strictly dental dimensions of the question. For instance, teaching a high school graduate in Sri Lanka to perform dental procedures in two years may not be all that different from doing the same thing for U.S. high school graduates. On the other hand, receiving such trainees into an established national healthcare system versus the nearly entirely privatized artisanal industry of dental practice as it exists in the U.S. could make an enormous difference in eventual outcome.

Compare introduction of dental therapists in New Zealand more than eighty years ago with their introduction in Australia about 40 years ago. The New Zealand model has been pointed to as an unqualified success. According to an article by David Nash, there are over 610 dental therapists who:

provide care for the country's 850,000 children. Ninety-seven percent of New Zealand's children are cared for by dental therapists who are assigned to every elementary and middle school ... at the end of a given school year essentially none of New Zealand's children in the School Dental Service [have] untreated tooth decay.²

But, transplanting the model elsewhere involves a lot more than simply the availability of dental therapists. In the New Zealand-Australia comparison, some important differences might be the relative size of the two populations, differences in the economy, and nature of the overall health care system.

New Zealand has a population of just over four million and a single dental school. When the dental therapist program was initiated there in the 1920's, the country was a welfare state with a highly regulated, protected, and subsidized economy-conditions that continued for more than sixty years thereafter and included free education and free health care. Introducing dental therapists into such a system could be relatively straightforward. In contrast, Australia has a population more than five-times larger, requiring establishment of a more formalized operational bureaucracy. In addition, dental therapists were introduced in Australia when the country was moving toward major economic liberalization and deregulation—a more public-private blend. The current health care system in Australia intermingles governmental and private health plans falling somewhere between a subsidized dental system and the nearly fully privatized system of the United States.

A recent report on oral health care in the Australian state of New South Wales identifies significant waiting lists for access to public oral health care, young children having minimal access to public oral health care, and a need for dramatic improvement in performance and accountability. Rural and remote communities have increasing need yet enjoy limited access to public oral health care. The same is true for many ethnic and indigenous communities having poor oral health and limited access to care.³ Admittedly, the situation would probably be much worse without dental therapists; but, the take-home message is not that, rather, it's about the system. The lesson is that the results obtained in New Zealand are not perfectly replicable based on the introduction of midlevel providers alone. In Australia it was unrealistic to expect dental therapists to make much of a difference if other elements of the system did not support change in ways that went far beyond the introduction and training of the providers themselves.

Finally, even purportedly good results in New Zealand may not be everything they've been cracked up to be: A March 6, 2011 article in the New Zealand Herald entitled "NZ children's dental health still among worst" states:

The dental health of young children continues to be among the worst in the developed world, figures reveal. Forty-four per cent of 5-year-olds have at least one decayed, missing or filled tooth, a school dental services report has found. The Government has spent $417 million on the problem since 2007 but the figures have shown little improvement. In 2000, 48 per cent of 5-year-olds had cavities, and the figure has not dropped below 43 per cent since. New Zealand rates are worse than the UK, US and Australia.

"Never Attribute to Malice..."

There's no question that efforts to introduce midlevel providers in the United States in the 1950's and 1970's gained little traction, whereas, introducing them in the 2000's in Alaska and Minnesota has gained a lot of traction. While it's fair to say that organized dentistry has pretty consistently opposed the dental therapist movement, I don't think it's fair to impugn dentists' motives. Consider the effort to introduce both dental nurses and advanced practice dental hygienists by the Forsyth Dental Center in Massachusetts in the 1950's and 1970's respectively. The history of these innovative programs has been detailed by David Nash.⁴ In 1949 the Massachusetts legislature authorized Forsyth to implement a pilot program that included 2-years of training to prepare and restore carious lesions under the supervision of a dentist:

The reaction and response of organized dentistry was swift and strong. The ADA House of Delegates passed multiple resolutions: ‘deploring' the program; expressing the view that any such program concerning the development of ‘sub-level' personnel, whether for experimental purposes or otherwise, be planned and developed only with the knowledge, consent, and cooperation of organized dentistry; and stating that a teaching program designed to equip and train personnel to treat children's teeth cannot be given in a less rigorous course or in a shorter time than that approved for the education of dentists … Faced with increasing pressure from organized dentistry in Massachusetts and nationally … Massachusetts Governor Paul Dever signed a bill in July, 1950 rescinding the enabling legislation that had been passed the year before.

In 1970 the story was repeated, however, now the intent was to expand the function of Forsyth dental hygiene students to include restorative procedures for children, including administering local anesthesia, preparing and placing Class I, II, and V amalgams as well as Class III and V composites. According to Nash, though the program proceeded well between 1970 and 1973, demonstrating "advanced training in restorative care for children could be accomplished in the ‘traditional two year dental hygiene curriculum by adding two summer sessions and condensing and combining some courses, the Massachusetts Board of Dental Examiners determined that the pilot project was a direct violation of the Dental Practice Act of Massachusetts leading the attorney general to force the closure of the Forsyth experiment in June 1974.

The account is accurate but incomplete. In isolation, organized dentistry and the state dental board come across very badly both in 1949 and 1970. The implication is that organized dentistry had the ulterior motive of protecting its own interest rather than the public's. But consider the context: what else was happening at the same time? In the late 1940's and 1950's organized dentistry became the major advocate for fluoridating community water supplies, for fluoridated dentifrice and, later, endorsed the use of sugar free confections and soft drinks. The profession was praised on the grounds that its stated positions on these issues could lead to its own demise, or at least to a significant drop in the need for dentists. It's hard to accept that these same individuals were totally self-serving on the matter of expanded auxiliaries and totally self-sacrificing on the eradication of dental caries. An alternative explanation is that organized dentistry really did believe that they were protecting the public's interest and that less qualified practitioners really did represent an unwarranted risk. At least in the 1950's organized dentistry's conclusions might be questioned, but not its motives.

The 1970's scenario is a more complex. That organized dentistry strongly opposed the Forsyth experiment with advanced practice dental hygienists is not in doubt, but consider the context. Figure 1 shows live births in the United States from 1950 projected to 2015. Most noticeable is an enormous drop in births centered on the mid 1970s. This is known as the baby bust, and was the predictable latent period attendant to the birth synchronization produced by World War II and revealed as an antecedent baby boom. Perhaps the effect was further compounded by the introduction of new methods of contraception and legalization of abortion. Nevertheless, the decrease in births was felt by dental practitioners in the form of open slots in their appointment books. The first to feel the effect were pediatric dentists. As more general dentists stopped referring children to pediatric specialists a realistic question arose by the early 1980's over whether a specialty for children's dentistry was even needed.

The next group of specialists to feel the effect was orthodontists. At one point, nearly one-third of orthodontic billings were made by general dentists. It was this drop in demand among adolescents that initiated a major movement toward adult orthodontics—previously relatively uncommon. Oral surgeons were next on the hit list. As fewer young adults were in need of removal of wisdom teeth, oral surgeons were encouraged to practice the newly defined "full scope" of the specialty and oral surgery became oral and maxillofacial surgery. Next look at the anticipated production of new dentists as experienced by practitioners of the 1970's and 1980's (Figure 2). While births were at an all-time low, dental schools were at an all-time high in churning out new dentists. The baby-bust came precisely 20-25 years after the baby boom—when the baby boomers would attend dental school. Contributing further to the greater number of individuals seeking to attend dental school was the Viet Nam war, which drove even more 22-26 year olds into dental school as a means of securing an exemption from mandatory military service.

From a practicing dentist's standpoint, business was at an all time low and new dentists were at an all-time high and would be for the foreseeable future. Further, credible claims were being made that the drop in patients emerged not from fewer births, but from long-predicted and permanent changes in disease patterns because of fluoridation effects. Organized dentistry in concert with universities mobilized to cut the production of dentists. Thus 7 dental schools closed outright. Schools that had previously shortened their educational programs from 4 years to 3 years now returned to a full four-year curriculum while decreasing class size and diminishing the through-put of students within dental educational institutions. The net capacity of the dental educational system dropped by about one-third overall. The perception at the time that there were too many dentists was an entirely thoughtful and defensible position. Temporally, it coincides precisely with the effort of the Forsyth Dental Center to expand services by auxiliaries when it made absolutely no sense to do so. In fact, as recently as 2005, a University of California Health Sciences report argued that "the supply [of dentists] appears to be adequate." Thus credible authority envisaged no absolute shortage of dentists, only a maldistribution—a problem potentially solvable through incentives to promote better distribution as opposed to inventing new categories of practitioners.

Thus, I am very reticent to criticize the profession or to question its motives. One who has studied for eight or more years for the privilege of treating human beings may find it a little difficult to move blithely into a realm where high school graduates have the same privilege. It does seem reasonable to ask whether the dignity accorded the human person and the privilege of providing direct patient care can be adequately imprinted through a purely technical education. Advocates for change take on a great burden to assure that their worthy intentions are achieved and that no harm is done—as do those in opposition.

1 Thinking in Systems: A Primer. DH Meadows. Chelsea Green Publishing; White River Junction, Vermont; 2008.

2 Improving Access to Oral Health Care for Children by Expanding the Dental Workforce to Include Dental Therapists. David A. Nash, Dental Clinics of North America Volume 53, Issue 3, July 2009, Pages 469-483. Oral Health Care Access

3 New South Wales Oral Health Implementation Plan 2005-2010. NSW Department of Health, June, 2007. 73 Miller Street, North Sydney, NSW 2060.th

4 Improving Access to Oral Health Care for Children by Expanding the Dental Workforce to Include Dental Therapists. David A. Nash, Dental Clinics of North America Volume 53, Issue 3, July 2009, Pages 469-483. Oral Health Care Access"