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Design of the Prevention of Adult Caries Study (PACS): A randomized clinical trial assessing the effect of a chlorhexidine dental coating for the prevention of adult caries

William M Vollmer1*, Athena S Papas2, James D Bader3, Gerardo Maupomé4, Christina M Gullion1, Jack F Hollis1, John J Snyder5, Jeffrey L Fellows1, Reesa L Laws1, B Alexander White6 and the PACS Collaborative Research Group

Author Affiliations

1 Center for Health Research, 3800 N. Interstate Blvd, Portland, Oregon 97227, USA

2 Tufts University School of Dental Medicine, 1 Kneeland St., Boston, MA 02111, USA

3 Dept. of Operative Dentistry CB#7450, University of North Carolina, Chapel Hill NC 27599- 7450, USA

4 Indiana University School of Dentistry, 415 Lansing St., Indianapolis IN 46202, USA

5 Permanente Dental Associates, 500 NE Multnomah St, Suite 100, Portland OR 97232, USA

6 DentaQuest Institute, 2400 Computer Dr, Westborough MA 01581, USA

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BMC Oral Health 2010, 10:23  doi:10.1186/1472-6831-10-23

Published: 5 October 2010



Dental caries is one of the primary causes of tooth loss among adults. It is estimated to affect a majority of Americans aged 55 and older, with a disproportionately higher burden in disadvantaged populations. Although a number of treatments are currently in use for caries prevention in adults, evidence for their efficacy and effectiveness is limited.


The Prevention of Adult Caries Study (PACS) is a multicenter, placebo-controlled, double-blind, randomized clinical trial of the efficacy of a chlorhexidine (10% w/v) dental coating in preventing adult caries. Participants (n = 983) were recruited from four different dental delivery systems serving four diverse communities, including one American Indian population, and were randomized to receive either chlorhexidine or a placebo treatment. The primary outcome is the net caries increment (including non-cavitated lesions) from baseline to 13 months of follow-up. A cost-effectiveness analysis also will be considered.


This new dental treatment, if efficacious and approved for use by the Food and Drug Administration (FDA), would become a new in-office, anti-microbial agent for the prevention of adult caries in the United States.

Trial Registration Number