In Vivo Comparison of Salivary Fluoride Levels Following the Application of Different 5% NaF Varnishes

This study will be a cross-over single blinded clinical study to evaluate the in vitro
fluoride release of three different brands of 5% NaF varnish. Subjects will be recruited at
the University of Michigan School of Dentistry and will participate in a 15 minute clinical
session at the beginning of each study arm, followed by 6 saliva collection recalls. During
these sessions a fluoride varnish or placebo will be applied to their teeth, and subsequent
salivary samples will be taken 1 hour, 4 hours, 6 hours, 24 hours, and 48 hours after the
application. All subjects will receive 3 commercially available varnishes, and a placebo
varnish. Between applications there will be a minimum of 2 weeks wash-out period. The goal
of this study is to determine if different formulations of varnish lead to differing amounts
of fluoride release. Despite their similar concentrations of NaF (5%), some in vitro data
have suggested that they may differ in the amount of fluoride release. Determining fluoride
release of these varnishes in vivo is important in assessing both the safety and efficacy of
the product.

Specific Aims

1. Determine the concentration of fluoride available in the oral cavity at different time
periods after the application of three different 5% NaF varnishes as measured in
unstimulated human saliva.

2. Compare the different patterns of fluoride release from each of the varnishes by
comparing the fluoride concentration in saliva at corresponding time periods .

3. Evaluate the validity of an in vitro model used to measure fluoride release from
varnishes.

Percentage difference in fluoride release between the in vivo and in vitro data obtained
from the same products will be compared.