This is the first study, to our knowledge, that examined the potential role that foreign-trained dentists can have on addressing dental workforce shortages and improving access to dental care for vulnerable populations. We used Washington State as a case study to test the hypotheses that compared to U.S.-trained dentists, foreign-trained dentists are more likely to participate in the Medicaid program and more likely to practice in a dental HPSA. Based on our findings, we arrived at two preliminary conclusions. First, significantly lower proportions of newly licensed, foreign-trained dentists participated in the Medicaid program than newly licensed, U.S.-trained dentists. Second, among newly licensed dentists who participated in the Medicaid program, there was no significant difference in the proportions of foreign- and U.S.-trained dentists practicing in a dental HPSA.
A possible explanation for our findings relates to dental school debt. School debt influences recent graduates' practice behaviors . A 2004 study conducted by the American Dental Education Association found that 90% of dental school seniors graduated with a mean student debt of $135,721 . In the early 1970s, the Institute of Medicine found that dental education subsidies were unnecessary, as the rate of return on dental education was large and subsidies did not yield more dentists who served the poor . Consequently, the cost of dental education has continued to increase, leading to a concomitant rise in indebtedness [33, 35]. It is unknown if foreign-trained dentists have greater student debt than U.S.-trained dentists.
After becoming licensed, one practice option for dentists is to work at a community health center, many of which serve Medicaid-enrolled patients and are located in dental HPSAs. Our findings suggest that newly licensed, foreign-trained dentists are not more likely to work in community health centers than U.S.-trained dentists. The average income of a community health center dentist is $73,000 less than that of a private practice dentist [36, 37]. This income differential may drive many foreign-trained dentists to the second practice option, which is to open their own private practice office or become an associate dentist in an established practice. It is common for experienced dentists to employ associates to grow their practices. Associate dentists may or may not become Medicaid providers, depending on the type of practice they join. Anecdotal evidence suggests that established dental practices with the capacity to hire an associate dentist are less likely to accept Medicaid patients given the busyness of the practice, which could explain why foreign-trained dentists are less likely to see Medicaid patients and not more likely to practice in a dental HPSA. In addition, 58.3% of foreign-trained dentists in our study were female. Previous work based on data from Washington State suggests that female dentists have different practice patterns from male dentists . As such, sex may confound the relationship between where a dentist was trained (U.S. versus foreign dental school) and the likelihood of treating vulnerable populations, a hypothesis worthy of further investigation.
Another explanation for our findings is that foreign-trained and U.S.-trained dentists, broadly speaking, may not differ on characteristics related to willingness to treat the underserved. It is a commonly held assumption that licensing foreign-trained health care professionals is the solution to workforce shortages [39, 40]. This may not be the case. A 2010 study found that efforts in Washington State to recruit foreign medical school graduates to medical HPSAs are effective at initially recruiting but less effective at retaining physicians in underserved areas . As in medicine and nursing, it is likely that foreign-trained dentists will continue to be an important part of the dental workforce in the future. However, long-term solutions to the maldistribution of dentists that involve foreign-trained dentists need to ensure that dentists locate to and remain in areas with the greatest need. In addition, policies that encourage foreign-trained dentists potentially result in "brain drain" abroad and reduce the capacity of foreign healthcare systems to serve their populations, which introduces ethical concerns . States must weigh these ethical considerations when developing licensing policies.
One-fifth of newly licensed dentists on our study were foreign-trained, suggesting that current policies in Washington State are not as restrictive as they were prior to 1985, when licensure rules changed. While other States such as Maryland, Massachusetts, and California have recently implemented innovative programs that make it easier for foreign-trained dentists to obtain licensure , there are no published evaluation data on these programs, making it to difficult to compare findings. However, the proportion of newly licensed, foreign-trained dentists in Washington is slightly greater than the estimated 17% of dentists in the U.S. presumed to be foreign-trained between 2002 and 2005 .
It is worrisome that only 20% of all newly licensed dentists in our study participated in the Medicaid program, which is the only way a dentist can be reimbursed for providing dental care to Medicaid-enrolled patients. While it is possible that some of these dentists may have become Medicaid providers at a later time, this is unlikely. A 2001 study found that newly graduated dentists in Louisiana were more likely to be active Medicaid providers than established dentists, which suggests that Medicaid participation is highest during the earliest years of practice . Our findings highlight a potential problem that the Washington Medicaid Program may have in recruiting new dentists to the program. Future efforts may need to be directed at introducing and promoting the Medicaid program to new dentists, especially to those who may be unfamiliar with Medicaid, and encouraging established dentists to participate in the program.
Our study has two limitations. First, having a Medicaid provider number does not ensure that the licensee actually saw any Medicaid-enrolled patients, nor does it provide information on participation intensity. Second, our data are limited in scope. A comprehensive data set would have allowed us to evaluate more complex models and to assess the impact of other factors (such as level of student debt, family expectations, beliefs about dental access problems) in comparing practice-related behaviors of foreign- and U.S.-trained dentists. We believe that all states should systematically collect data on newly licensed foreign- and U.S.-trained dentists. These data should be easily linkable to Medicaid claims data for individual providers so that state Medicaid programs can be evaluated and compared. Effective programs could then be identified and promulgated in other states. In addition, future research efforts should be directed at collecting qualitative data from newly licensed dentists to identify the factors associated with the decision to treat vulnerable populations.