Open Access Open Badges Research article

A surrogate method for comparison analysis of salivary concentrations of Xylitol-containing products

Christine A Riedy1*, Peter Milgrom1, Kiet A Ly1, Marilynn Rothen2, Gregory Mueller2, Mary K Hagstrom2, Ernie Tolentino3, Lingmei Zhou1 and Marilyn C Roberts4

Author Affiliations

1 Northwest/Alaska Center to Reduce Oral Health Disparities and Department of Dental Public Health Sciences, School of Dentistry, University of Washington, 1959 NE Pacific St., Box 357475 Seattle, WA USA

2 Regional Clinical Dental Research Center, School of Dentistry, University of Washington, 1959 NE Pacific St., Box 357480 Seattle, WA USA

3 Department of Biobehavioral Nursing and Health Systems, School of Nursing, University of Washington, 1959 NE Pacific St., Box 357266 Seattle, WA USA

4 Department of Environmental & Occupational Health Sciences, School of Public Health and Community Medicine, University of Washington, 1959 NE Pacific St., Box 357234, Seattle, WA USA

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BMC Oral Health 2008, 8:5  doi:10.1186/1472-6831-8-5

Published: 11 February 2008



Xylitol chewing gum has been shown to reduce Streptococcus mutans levels and decay. Two studies examined the presence and time course of salivary xylitol concentrations delivered via xylitol-containing pellet gum and compared them to other xylitol-containing products.


A within-subjects design was used for both studies. Study 1, adults (N = 15) received three xylitol-containing products (pellet gum (2.6 g), gummy bears (2.6 g), and commercially available stick gum (Koolerz, 3.0 g)); Study 2, a second group of adults (N = 15) received three xylitol-containing products (pellet gum, gummy bears, and a 33% xylitol syrup (2.67 g). For both studies subjects consumed one xylitol product per visit with a 7-day washout between each product. A standardized protocol was followed for each product visit. Product order was randomly determined at the initial visit. Saliva samples (0.5 mL to 1.0 mL) were collected at baseline and up to 10 time points (~16 min in length) after product consumption initiated. Concentration of xylitol in saliva samples was analyzed using high-performance liquid chromatography. Area under the curve (AUC) for determining the average xylitol concentration in saliva over the total sampling period was calculated for each product.


In both studies all three xylitol products (Study 1: pellet gum, gummy bears, and stick gum; Study 2: pellet gum, gummy bears, and syrup) had similar time curves with two xylitol concentration peaks during the sampling period. Study 1 had its highest mean peaks at the 4 min sampling point while Study 2 had its highest mean peaks between 13 to 16 minutes. Salivary xylitol levels returned to baseline at about 18 minutes for all forms tested. Additionally, for both studies the total AUC for the xylitol products were similar compared to the pellet gum (Study 1: pellet gum – 51.3 μg.min/mL, gummy bears – 59.6 μg.min/mL, and stick gum – 46.4 μg.min/mL; Study 2: pellet gum – 63.0 μg.min/mL, gummy bears – 55.9 μg.min/mL, and syrup – 59.0 μg.min/mL).


The comparison method demonstrated high reliability and validity. In both studies other xylitol-containing products had time curves and mean xylitol concentration peaks similar to xylitol pellet gum suggesting this test may be a surrogate for longer studies comparing various products.