Reply to Letter Regarding “Preventive Dental Care and Overall Medical Expenditures”

Am J Manag Care. 2026;32(9):In Press

We thank the reader for highlighting the importance of rigorous methods for generating high-quality evidence to inform policy. We agree that the central question is not whether preventive care is beneficial, but whether evidence on subsequent medical utilization and costs is methodologically robust, internally valid, and policy-relevant to guide changes in practice, coverage, and/or reimbursement. This question is especially important in oral health, where prior research has often faced data and design limitations that make it difficult to determine whether preventive dental care reduces subsequent medical spending.

Poor oral health is associated with several systemic diseases.¹ However, evidence that treating oral disease prevents or reduces systemic disease, or reduces subsequent medical costs, remains limited and inconsistent.^2-4 In our view, an important challenge in this literature is that many studies rely on analyses of nonexperimental data using naive observational designs in which patients who receive preventive dental care differ systematically from those who do not. These differences may include health-related social needs, care-seeking behaviors, transportation access, personal hygiene practices, and other factors that are typically unavailable in claims data. Consequently, analyses may be biased. For example, results may attribute differences in health outcomes or expenditures to preventive dental care when they may be, at least in part, driven by unmeasured confounding.

Our study sought to address this challenge by using an instrumental variable (IV) derived from administrative data.⁵ This approach helps address variation in preventive dental care use that is plausibly unrelated to patients’ underlying health status, behaviors, or access to care. Notably, our findings differed from the positive cost-saving effects of dental care reported in prior studies. Although no single study can resolve this question definitively, our results raise the possibility that residual confounding in conventional observational analyses may overestimate the benefits reported in prior work. Although the validity of our empirical findings relies on assumptions that cannot be fully proven, the article offers a methodologically important contribution. Additionally, our empirical findings are based on data from Indiana Medicaid patients and may not generalize to other settings because the effects of preventive dental care may vary across populations, benefit designs, baseline oral health status, and time horizons.

Policy decisions should not rely on any single study or methodological approach. Our findings highlight the need for additional quasi-experimental research designed to strengthen causal inference from nonexperimental data. Future studies could apply a broader range of approaches, including difference-in-differences, regression discontinuity, and other natural-experiment designs in diverse populations, benefit designs, and locations. Together, such designs, in conjunction with IV approaches, can help determine for whom, under what benefit design, over what time horizon, and through which mechanisms preventive dental care may improve overall health, chronic disease outcomes, or costs. We thank The American Journal of Managed Care for the opportunity to contribute to this important discussion. n

Author Affiliations: Department of Health Policy and Management, Indiana University Richard M. Fairbanks School of Public Health (HLT, AMH, NM, JB), Indianapolis, IN.

Source of Funding: Research reported in the original publication was in part supported by the National Library of Medicine of the National Institutes of Health under award T15LM012502. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the National Library of Medicine.

Author Disclosures: The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (HLT, AMH, NM, JB); drafting of the manuscript (HLT, AMH, NM, JB); and critical revision of the manuscript for important intellectual content (HLT, AMH, NM, JB).

Address Correspondence to: Heather L. Taylor, PhD, MPH, RDH, Department of Health Policy and Management, Indiana University Richard M. Fairbanks School of Public Health, 1050 Wishard Blvd, Ste 6185, Indianapolis, IN 46202. Email: hhavens@iu.edu.

REFERENCES

1. Monsarrat P, Blaizot A, Kémoun P, et al. Clinical research activity in periodontal medicine: a systematic mapping of trial registers. J Clin Periodontol. 2016;43(5):390-400. doi:10.1111/jcpe.12534

2. Pihlstrom BL, Hodges JS, Michalowicz B, Wohlfahrt JC, Garcia RI. Promoting oral health care because of its possible effect on systemic disease is premature and may be misleading. J Am Dent Assoc. 2018;149(6):401-403. doi:10.1016/j.adaj.2018.03.030

3. Treat T, Jones D, Lorenzano N, et al. Design characteristics of studies evaluating the effect of non-surgical periodontal treatment on systemic health outcomes. J Periodontol. 2026;97(4):619-632. doi:10.1002/JPER.24-0847

4. Taylor HL, Rahurkar S, Treat TJ, Thyvalikakath TP, Schleyer TK. Does nonsurgical periodontal treatment improve systemic health? J Dent Res. 2021;100(3):253-260. doi:10.1177/0022034520965958

5. Taylor HL, Holmes AM, Menachemi N, Schleyer T, Sen B, Blackburn J. The relationship between preventive dental care and overall medical expenditures. Am J Manag Care. 2024;30(2):e39-e45. doi:10.37765/ajmc.2024.89499