Dental Care

Improving Access and Quality (continued)

Use of Dental Crowns and Alternatives Varies

Another AHRQ-funded study looked at the use of dental crowns and their alternatives.16 It found that the use of crowns among patients with substantially compromised posterior teeth varies significantly by age and region and that these differences, in turn, are related to substantial differences in costs. The study found that older patients are significantly more likely to receive crowns than young patients. Patients 50 and over had an average cost per tooth of $269, compared to an average cost per tooth of $181 for patients ages 18-34. Also, regional variation in the provision of crowns appears to contribute to a 31-percent difference in the average per-tooth treatment cost between the highest and lowest cost regions. The most notable geographic difference in average cost per tooth was between the Northeast ($173) and the West ($251). Based on the sample included in the study, the average cost of restoring a tooth requiring either a crown or its alternative was $225. Since crowns can cost up to six times as much as the alternative, seemingly small differences in the use of crowns can have major effects on overall costs.16

In addition, the ratio of crowns to their alternatives varies more than the amount that can be accounted for by the patient and practice factors that were measurable through the claims data used in this study, raising questions about the consistency of dentists' treatment recommendations.17 For example, 43 percent of practices provided crowns at either 50 percent below or 150 percent above the expected rate. This variation found at the practice level also raises concerns about the appropriateness of care. However, as the researchers note, "...a determination of appropriateness depends upon comparison with a known standard of treatment effectiveness, which is currently unavailable."15 Other reasons for disagreement about treatment recommendations could include differences in the thoroughness of the examination, application of diagnostic criteria used to define a condition, assessment of risk, interpretation of nonclinical patient factors, and interpersonal interaction between the dentist and patient.

The researchers concluded that if a substantial portion of the variation noted in this study indeed stems from dentists' idiosyncratic use of crowns, the profession has a clear indication of the need to improve knowledge of treatment outcomes among practitioners. Since there is substantial disagreement about the relative life expectancies of crowns vs. their alternatives, the researchers conclude that more outcomes effectiveness research is needed, given the wide difference in the costs of alternative treatments.

In fact, one of the researchers points out that the dental profession lacks basic evidence that many of the dental treatments provided are even effective.17 He also suggests that soon payers and consumers will no longer accept anecdotal stories about quality; they will want measurement and quantification instead. He argues that dental schools are the logical site for the development of valid, reliable, and acceptable health services research methods and databases. In addition, he describes the actual development of an insurance claims database to demonstrate the types of investigations possible with it. This database was used to conduct the study described here on practice variations in the use of crowns.16 

Dental Performance Measures Have Been Developed 

Performance measures for dental care plans can improve the ability to measure effectiveness of care and use of services, but no standardized measures of the performance of dental care plans exist. Currently most plans do not collect sufficient administrative information to determine the outcomes of care delivered by their providers. To fill the gap left by the lack of standardized performance measures, AHRQ-funded researchers developed seven effectiveness-of-care measures and six use-of-services measures modeled after the Health Plan Employer Data and Information Set (HEDIS®) measures of medical care.18

Effectiveness-of-Care Measures

  • Current disease activity assessment.
  • Preventive treatment for caries-active children and adults.
  • New caries.
  • Periodontal treatment for perio-present adults.
  • Improvement in periodontal status.
  • Deterioration in periodontal status.
  • Tooth loss.

Use-of-Services Measures

  • Receipt of prophylaxis.
  • Preventive treatment: restorative treatment ratio.
  • Casting (e.g., crown, inlay): large direct fillings ratio.
  • Endodontic treatment: extraction ratio.
  • Receipt of third molar (wisdom tooth) extractions.
  • Mean number of third molars extracted.

Source: Bader JD, Shugars DA, White A, et al. Development of effectiveness of care and use of services measures for dental care plans. J Public Health Dent 1999;59(3):142-9.

The measures enable oral health plans to determine the percentage of enrollees with various conditions and the percentage receiving various services. Since basic restorative and periodontal care accounts for one-half of all dental expenditures and approximately 50 percent of the population has some dental care coverage, these measures cover care costing more than $10 billion.

All of the measures are expressed as proportions, i.e., the proportion of all enrollees meeting certain criteria who have experienced a certain clinical outcome or have received a certain service. For example, the first effectiveness-of-care measure, "current disease activity assessment," reports the percentage of all enrollees who have had a caries activity assessment within 2 years of the end of the reporting year. The proportions for children (ages 6-17) and adults (ages 18 and over) are reported separately. The second and third measures address dental caries: a process measure assessing receipt of appropriate preventive services such as fluoride treatment or dental sealants, and an outcome measure assessing caries experience among enrollees. This pattern is repeated for periodontal disease. A final measure assesses the extent of tooth loss from both diseases.

Of the six use-of-services measures, three are ratio measures comparing the provision of services that could be considered alternative therapies (e.g., endodontic treatment vs. extraction). Two measures are concerned with wisdom tooth (third molar) extractions. Another measure is a traditional assessment of the proportion of enrollees receiving prophylaxis.

The two groups of measures were pilot tested using administrative data from two group model oral health plans with approximately 205,000 eligible enrollees. The testing provided partial evidence that the measures are reliable and sensitive to differences among plans. However, the results reported in the study are not to be taken as benchmarks for comparison with other dental plans since they are the first such performance data to be reported for any dental plan.

The measures offer several advantages that can help promote their implementation. They can be calculated directly from a dental plan's administrative data system (assuming that the system included diagnostic codes), thereby minimizing data collection costs and related recording errors. They are standardized to facilitate comparisons across plans. They include a means of risk adjustment to account for differing oral disease status among enrollees of different plans. However, the measures, in their final form, cannot be widely implemented immediately because diagnostic codes are not routinely used in dentistry and a universally accepted set of codes is not available at present. The researchers also reported a set of interim measures that can be applied using audit-based data until carriers do include diagnostic codes in their administrative data systems.19

Scientific Evidence for Tooth Decay Treatment Strategies Is Limited

Measuring the quality of care presupposes the ability to systematically evaluate the validity and effectiveness of diagnostic, preventive, and surgical interventions. AHRQ, in a collaborative effort with the National Institute of Dental and Craniofacial Research (NIDCR), sponsored an evidence report systematically evaluating research on the diagnosis, prevention, and nonsurgical treatment of dental caries.20 The Evidence-based Practice Center (EPC) performing the analysis looked at 39 studies describing the performance of diagnostic methods.f The analysis included separate evaluations for different types of tooth decay (e.g., cavitated lesions, lesions involving dentin, enamel lesions) and also for different surfaces and tooth types.

The EPC report found that that the strength of the evidence on the performance of almost all diagnostic methods is poor. Several factors were responsible:

  • An insufficient number of studies.
  • Variation among reported results.
  • The quality of the available studies.

The evidence did not support the superiority of either visual or visual/tactile diagnostic methods since the number of available assessments was small and there was substantial variation among the reports for each method. The evidence suggests, but is not conclusive, that some digital radiographic methods offer small gains in sensitivity compared to conventional film x-rays. The evidence also suggests that electrical conductance methods may offer heightened sensitivity on occlusal surfaces, but at the expense of specificity. Again, the evidence was not conclusive.

The EPC also reviewed nine methods of managing caries-active individuals: fluoride varnishes, fluoride topical solutions, fluoride rinses, chlorhexidine varnishes, chlorhexidine topicals, chlorhexidine rinses, combined chlorhexidine-fluoride applications, sealants, and other approaches. In its analysis of 35 studies, the evidence for the efficacy of fluoride varnishes was rated as fair and the evidence for all other methods was incomplete.g

Once again, the number of available studies for any specific method proved to be a serious limitation. Among studies addressing a method, the variety of experimental protocols, comparison groups, and other community and individual preventive dentistry exposures further restricted the opportunity to draw conclusions about the efficacy of specific methods. Also, generalization from the studies to the broader U.S. population is problematic, as nearly all studies included only children and evaluated changes only in the permanent teeth.

Finally, the EPC report evaluated the the efficacy of preventive methods among individuals who have experienced, or are expected to experience, an elevated incidence of noncavitated tooth decay. Here the evidence was rated as incomplete, since the team found only five studies addressing the topic. No conclusions were drawn.

f. Evidence reports are based on rigorous, comprehensive reviews of relevant scientific literature performed under contract by Evidence-based Practice Centers. The reports' emphasis is on explicit and detailed documentation of methods, rationale, and assumptions. The goal of these reports is to provide the scientific foundation that public and private organizations can use to develop their own clinical practice guidelines, quality measures, review criteria, and other tools to improve the quality and delivery of health care services.
g. The conclusions of the EPC report apply to research published between 1966 and 1999. The earlier discussion of sealant effectiveness was based on research published in 2001.

More AHRQ-Funded Evidence Reports on Dental Care Are Available

Cardiovascular Effects of Epinephrine in Hypertensive Dental Patients

AHRQ and NIDCR sponsored and issued an evidence report on the cardiovascular effects of epinephrine in hypertensive dental patients.21 Epinephrine is widely used as an additive in local anesthetics to improve the depth and duration of the anesthesia, as well as to reduce bleeding. The added risks attributed to the use of epinephrine in hypertensive patients include the increased probability of acute hypertensive crisis (dangerously high blood pressure), angina pectoris, myocardial infarction, and cardiac arrhythmias.

The EPC looked at five studies on the outcomes of the use of epinephrine-containing anesthetic solutions in hypertensive patients. The report rated the evidence on this issue as poor because the outcomes considered in the five studies did not represent a reasonably complete assessment of risk indicators. Also, transient effects in blood pressure and heart rate, the principal outcomes reported, might have remained undetected in three of five studies.

The EPC recommended that a long-term research study be initiated in one or more large dental clinics in order to quantify the magnitude of additional risk represented by the use of epinephrine in hypertensive dental patients.

Management of Dental Patients Who Are HIV Positive

Another evidence report cosponsored by AHRQ and NIDCR focused on several aspects of the dental management of a special population subgroup—the estimated 900,000 people in the United States with HIV/AIDS.22 These aspects include:

  • Complications associated with invasive dental treatments.
  • Dental conditions as markers or indicators of change in HIV serostatus and immunosuppression.
  • The efficacy or effectiveness of available antifungal drugs to prevent or treat oral candidiasis.

The EPC found that there is limited evidence on the risks of oral procedures among people with HIV/AIDS. Very few studies have been reported, and only two types of procedures—root canal therapy and extractions—have been investigated. From this limited base, there is little evidence of unusual rates or severity of complications for these procedures among people with HIV/AIDS.

Evidence for the utility of selected oral lesions as markers for seroconversion is limited to a single study of a single oral condition—candidiasis. The review does not suggest the use of oral conditions as markers for seroconversion.

The evidence with respect to the efficacy of fluconazole to prevent oropharyngeal candidiasis is good, but for other antifungal agents there is no evidence. The situation is different with respect to the effectiveness of antifungals as treatments for oropharyngeal candidiasis. With the exception of amphotericin B, the evidence is good that all tested antifungals are effective, although all are not equally effective.

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Ongoing Research and Programs

U. S. Preventive Services Task Force (USPSTF) Recommendations on Dental Care. In fall 2003, the USPSTF will issue recommendations to cover primary prevention in pre-school-aged children. These recommendations will update the previous USPSTF recommendations, which were issued in 1996.

The Effect of Public Insurance on Oral Health Outcomes. University of North Carolina. R03 HS11514. This project represents an in-depth comparison of the use of dental services, effectiveness of established pediatric oral health performance measures, and oral health status for children enrolled in either the North Carolina Medicaid program or the North Carolina Health Choice for Children program (North Carolina's SCHIP program). This study provides an opportunity to determine the benefits of public dental insurance for low-income children when it is structured similarly to private insurance.

Effects of WIC on Child Medicaid Dental Use and Costs. University of North Carolina. R03 HS11607. The purpose of this research project is to examine the relationship of the Women, Infants and Children's Supplemental Food Program (WIC) on the oral health use patterns and cost to the Medicaid program of children under age 5. The current low level of oral health service use in Medicaid had presented a major public policy challenge, as evidenced by reports from the Office of Technology Assessment, the General Accounting Office, and the Office of the Surgeon General. This investigation will examine the role of a partnership between Medicaid and WIC, and its effects on Medicaid use and expenses.

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Despite a falling general rate of tooth decay among children, widespread disparities exist in the provision of care to poor and minority populations because of a cluster of access and financial issues. Availability of coverage and provider reimbursement rates seem to make a difference in access to care and in quality of care.

Measuring the quality of dental care provided through dental care plans is a difficult task, but one that has parallels in performance measures already in use for health care. The quality of dental care provided by oral health plans could benefit if performance measures developed for dental services by AHRQ-funded research were put into broader use. AHRQ's evidence reports, such as the one on validity and efficacy of diagnostic, treatment, and preventive strategies for carious lesions, are designed to evaluate the strengths and weaknesses of existing research on a broad array of health care subjects. Where gaps in the research are shown to exist, AHRQ-funded research, such as evaluation of the effectiveness of dental sealants, can help to address the need for more evidence-based practice. In addition, the relatively recent growth in alternative treatments available for both diagnosis and management of dental caries has yet to be fully assimilated by dental practice. Thorough reviews of methods for diagnosis and management of dental caries should assist in that assimilation process.

AHRQ's research has continued to point out the disparities in the provision of care that need to be addressed, the possibility of systematic measurement of dental plan performance leading to improvements in the quality of care, and the paths that dental research should take in pursuing the goal of evidence-based practice.

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AHRQ-Funded Research

The research programs discussed in this report are:

  • Clinical Performance Measures for Dental Plans, University of North Carolina School of Dentistry. The project developed measures of performance for dental care plans. The dimensions of performance for which measures were developed include the effectiveness of the care provided by the plan (the extent to which appropriate evaluation and treatment is provided and new disease is prevented), use of services (the rates and/or ratios at which selected services are provided), and access (the availability of plan benefits to enrollees).
  • Strategies for Management of Dental Caries in Children, University of North Carolina School of Dentistry. This project used North Carolina Medicaid data to explore factors associated with providers' use of sealants in this population, including the initiation of a reimbursement benefit for dental sealants.
  • The Effect of Medicaid Policy on Dentist Participation, Sheps Center for Health Services Research, University of North Carolina. This project studied how changes in Medicaid policy, in particular fee increases and the size of the Medicaid population, affect providers' participation in the North Carolina Medicaid program. In addition, the study explored the relationship between Medicaid price increases and charges to non-Medicaid dental patients.

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*7. Weintraub JA, Stearns SC, Rozier G, et al. Treatment outcomes and costs of dental sealants among children enrolled in Medicaid. Am J Public Health 2001;91(11):1877-81. 

*8. Strayer MS, Kuthy RA, Caswell RJ, et al. Predictors of dental use for low-income, urban elderly people upon removal of financial barriers. Gerontologist 1997;37(1):110-16. 

*9. Mayer ML, Stearns SC, Norton EC, et al. The effects of Medicaid expansions and reimbursement increases on dentists' participation. Inquiry 2000;37:33-44. 

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*13. Bader JD, Shugars DA. Variations in dentists' clinical decisions. J Public Health Dent 1995;55(3):181-8. 

*14. Bader JD, Shugars DA. Agreement among dentists' recommendations for restorative treatment. J Dent Res 1993;72(5):891-6. 

*15. Shugars DA, Bader JD. Cost implications of differences in dentists' treatment decisions. J Public Health Dent 1996;56(4):219-22. 

*16. Shugars DA, Hayden WJ, Crall JJ, et al. Variation in the use of crowns and their alternatives. J Dent Educ 1997;61(1):22-8. 

*17. Hayden WJ. Dental health services research utilizing comprehensive clinical databases and information technology. J Dent Educ 1997;61(1):47-55. 

*18. Bader JD, Shugars DA, White A, et al. Development of effectiveness of care and use of services measures for dental care plans. J Public Health Dent 1999;59(3):142-9. 

*19. Bader J, Shugars D, White A, et al. Evaluation of audit-based performance measures for dental care plans. J Public Health Dent 1999;59(3):150-8. 

*20. Diagnosis and management of dental caries. Summary. Evidence Report/Technology Assessment Number 36. AHRQ Pub. No. 01-E055, February 2001. Agency for Healthcare Research and Quality, Rockville (MD). AHRQ Web site: 

*21. Cardiovascular effects of epinephrine in hypertensive dental patients. Summary. Evidence Report/Technology Assessment Number 48. AHRQ Pub. No. 02-E005, March 2002. Agency for Healthcare Research and Quality, Rockville (MD). AHRQ Web site: 

*22. Management of dental patients who are HIV positive. Summary. Evidence Report/Technology Assessment Number 37. AHRQ Pub. No. 01-E041, March 2001. Agency for Healthcare Research and Quality, Rockville (MD). AHRQ Web site:

*AHRQ-funded/sponsored research.

Page last reviewed July 2003
Internet Citation: Dental Care: Improving Access and Quality (continued). July 2003. Agency for Healthcare Research and Quality, Rockville, MD.