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ADA Scientific Study Finds Surgical Midlevel Providers Do Not Reduce Overall Rates of Dental Decay

January 02, 2013

Contact Information:
Rob Raible: Telephone: 202.789.5166 Email:

A report published today in the peer-reviewed Journal of the American Dental Association details a nearly year-long systematic review of scientific papers about the use of non dentists, generally referred to as midlevel dental providers, to perform such irreversible surgical procedures as restorations (fillings) and extractions.

“The expert panel and the ADA can be proud of the work that went into this report,” said ADA President Robert A. Faiella, DMD, MMSc.  “It is an unprecedented look at these issues.”

The systematic review sought to answer this question: “In populations where non dentists conduct diagnostic, treatment planning, and/or irreversible surgical dental procedures, is there a change in disease increment, untreated dental disease and/or cost-effectiveness of dental care?”  

The report’s principal findings about the inclusion in the dental team of midlevel providers who perform irreversible procedures include: 

1. The quality of the available evidence is poor.  Caution is needed when comparing the results to the present-day US population.

• A search of 13 databases yielded 7,701 potentially applicable citations, eventually yielding 18 studies that met the review’s rigorous inclusion criteria.  Of the 18 studies, some were quite old, having been published as early as the 1950s.  Seven were published prior to 1980. The authors also noted that World Health Organization data clearly documents decreases of up to 80 percent in caries (cavities) in developed nations over the past 40 years, which have coincided with many changes in oral health prevention and attitudes toward oral health, and that this change has occurred irrespective of the makeup of the dental workforce.

• Of the 18 studies that met the inclusion criteria, the authors judged 12 to be at high risk of bias, five at moderate risk of bias, and one at low risk of bias.

• There were no randomized, controlled studies available. 

2. There is no difference in the overall caries rates between populations treated by therapists and those treated solely by dentists, as measured by diseased, missing and filled teeth (DMFT) scores.

Caries rates do decline over time in populations treated by dental therapists, as measured by DMFT scores.  And similar decreases have occurred in countries that do not employ dental therapists. This could be due to many variables, including the introduction of water fluoridation and fluoridated toothpaste, preventive treatments such as topical fluorides and dental sealants, as well as greater awareness among the populations of the importance of good oral hygiene and regular preventive dental care. 

3. There was a greater decrease in untreated caries in the therapist-treated populations than in dentist-only-treated populations.  Over time, there was also a decrease in untreated caries in therapist-treated populations.  This is likely a result of a greater number of personnel (non dentists) available to treat caries.

4. The review found no data that addressed cost-effectiveness, defined as the real cost of reducing disease rates, or about diseases other than caries.

“This analysis shows mid-level providers who provide surgical treatment do not result in reduced rates of dental caries in the population,” said J. Timothy Wright, DDS, MS, the report’s principal author, adding, “Oral health disparities exist regardless of the provider workforce model.”

The report’s authors emphatically stressed the limitations of their investigation, writing, “Even the best studies available are of poor quality, and there is a clear need for additional research to assess the effectiveness of midlevel providers as a means to reduce overall disease burden.”

“To put it simply, the report shows that if more personnel are treating cavities, more cavities get treated,” said Dr. Faiella.  “But that does nothing to reduce the number of people getting cavities.  And it points up the futility of a delivery system based on surgically treating disease that could have been prevented.”   

A systematic review is a critical assessment and evaluation of all research studies that address a particular clinical issue. The researchers use a scientific method to locate, assemble, and evaluate a body of literature on a particular topic using a set of specific criteria.   The ADA review process was painstaking and adhered strictly to the ADA guidelines for evidence-based dentistry. 

The workgroup called for “well-designed prospective cohort studies” to better evaluate the impact of midlevel providers on incidence and treatment of dental caries.

About the ADA

The not-for-profit ADA is the nation's largest dental association, representing 162,000 dentist members. The premier source of oral health information, the ADA has advocated for the public's health and promoted the art and science of dentistry since 1859. The ADA's state-of-the-art research facilities develop and test dental products and materials that have advanced the practice of dentistry and made the patient experience more positive. The ADA Seal of Acceptance long has been a valuable and respected guide to consumer dental care products. The monthly The Journal of the American Dental Association (JADA) is the ADA's flagship publication and the best-read scientific journal in dentistry. For more information about the ADA, visit For more information on oral health, including prevention, care and treatment of dental disease, visit the ADA's consumer website