Pharmacokinetics of Advantage Anti-Caries Varnish: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pharmacokinetics of Advantage Anti-Caries Varnish (NCT04183231), a na phase 2 study. The primary outcome is Observed Iodine Tmax.

2. Clinical Question

The study aim was to characterize the kinetics of iodine and fluoride following topical application of a combined PVP-I and NaF varnish in healthy adults. In practical statistical terms, the primary question is descriptive: what was the recorded time to maximum serum iodine concentration after application? The registry identifies the endpoint and its measurement schedule, but does not post a numerical result for it.

Because there is one group and no control condition, the study cannot estimate a between-group treatment contrast. It can describe measurements following the varnish application if those data are reported, but the primary endpoint result is not reported in the registry record. The record also does not provide a numerical fluoride endpoint result in the material available for this analysis.

This distinction matters: the endpoint concerns the timing of a maximum concentration, not whether the varnish prevents dental caries or improves a clinical outcome. The registered condition is dental caries, but the summary describes healthy adults and a pharmacokinetic aim. No clinical effectiveness conclusion follows from the endpoint description alone.

3. Trial Design

This is a completed Phase 2 study, with a registered enrollment of 16. The study dates in the registry are 2016-11-01 for the start and 2017-02-28 for primary completion. The status is recorded as completed. These administrative details establish the registered scale and timing of the study, but do not establish how many participants completed each assessment or contributed to each analysis.

The design is listed as single-group. The intervention is anti-caries varnish, described as a topical dental varnish containing 10% PVP-I and 2.5% NaF. The arm description specifies a 0.4 ml single application to the teeth. Allocation is recorded as not applicable, and masking is recorded as none. There is no like-for-like control arm, so the study is not a randomized comparison.

The study aim is pharmacokinetic characterization of iodine and fluoride after topical application in healthy adults. The primary endpoint is observed iodine Tmax, defined as time to maximum serum iodine concentration in hours. The stated assessment times are 0, 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose. The registry lists 13 outcome measures overall, but a numerical result for the primary endpoint is not reported in the registry record.

Several design details that would help interpret the conduct and analysis are not reported in the registry record. These include eligibility criteria beyond the summary’s description of healthy adults, the planned sample-size justification, the analysis population, participant flow, handling of missing measurements, and a statistical analysis plan. The record’s completion status should not be interpreted as evidence that every enrolled participant posted every scheduled measurement. Without posted participant-level or summary endpoint results, the study’s observed pharmacokinetic pattern and its precision cannot be assessed.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Observed Iodine Tmax, measured over 0, 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose.

Observed iodine Tmax is the time, measured in hours, at which serum iodine reaches its maximum concentration after the varnish is applied. The registry defines the endpoint as time to maximum serum concentration of iodine. Measurements are scheduled at 0, 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose.

As a pharmacokinetic measure, Tmax describes the timing of a peak rather than the peak’s magnitude. A concentration profile can help characterize how a substance appears in serum over the observed period. Tmax by itself does not state how high the maximum concentration was, how long concentrations remained elevated, or whether a clinical outcome changed. Those are distinct questions and require their own measures and results.

The registry specifies that the primary outcome is summarized as a mean with standard deviation. In general, the mean describes the central value of observed times, while the standard deviation describes how dispersed individual times are around that mean. The result for this endpoint, including its mean and standard deviation, is not reported in the registry record. The endpoint is therefore identifiable from the record, but its observed value and variability cannot be interpreted from the posted information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered primary endpoint is a continuous measure: observed iodine Tmax in hours. The registry specifies a mean as the summary parameter and standard deviation as the measure of dispersion. These choices describe how the endpoint would be summarized, but the numerical summary itself is not reported in the registry record.

What does a mean summarize?

General explanation: a mean is the arithmetic average of observed values. For a time-to-maximum endpoint, it would summarize the average recorded time at which serum iodine reached its maximum among the participants included in the analysis. The mean does not show whether the individual observations cluster closely or whether some participants have notably earlier or later values. That is why a dispersion measure is also useful.

What does the standard deviation add?

General explanation: the standard deviation describes the spread of individual measurements around their mean. A smaller spread indicates values closer to the mean, while a larger spread indicates more variability. It is not the same as a confidence interval. A standard deviation describes participant-to-participant variation in the observed data; a confidence interval describes uncertainty about an estimated quantity, such as a population mean, under specified assumptions. Neither the mean nor standard deviation for iodine Tmax is reported in the registry record, and no confidence interval is reported.

How does the assessment schedule relate to Tmax?

The listed measurement times are 0, 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose. In general, observations taken at scheduled times provide information about the measured concentration profile. A peak-time endpoint depends on identifying when the maximum occurs among the available measurements or on a specified method for estimating it. The registry record does not report the operational method used to identify or calculate Tmax, including how a maximum between scheduled measurement times would be handled.

That methodological detail matters because observed timing is linked to the observation schedule and the rule used to define the maximum. The record supplies the assessment schedule and endpoint definition, but does not report whether interpolation, model-based estimation, or another method was used. No such method should be inferred from the endpoint name alone.

What can a single-group design estimate?

General explanation: a single-group study can summarize measurements observed after an intervention in that group. Without a separate comparison condition, it cannot estimate a between-group difference. The registry lists the design as single-group, allocation as not applicable, and masking as none. Thus, the record does not describe randomized allocation or a blinded comparison. Any estimate from this design would be descriptive of the observed group and would not isolate a comparative effect from changes or influences that might occur without the intervention.

The stated aim is to characterize iodine and fluoride kinetics after topical application. This is distinct from estimating whether the varnish changes a clinical outcome relative to a control. The endpoint named as primary focuses on the timing of maximum serum iodine concentration. A result for this endpoint would not, on its own, describe the magnitude of the maximum concentration or provide a direct measure of dental-caries outcomes.

What does a confidence interval usually mean?

General explanation: a confidence interval gives a range of values compatible with an estimate under a statistical procedure and its assumptions. Its width conveys precision: a narrower interval generally indicates greater precision than a wider interval. Interpretation requires knowing what estimate the interval concerns, how it was calculated, and what assumptions were used. The registry record does not report a confidence interval for iodine Tmax or the analysis method needed to interpret one.

Similarly, a p-value is associated with a specified statistical test and null hypothesis. It is not a measure of effect size, clinical importance, or the probability that a hypothesis is true. No p-value or hypothesis test for the primary endpoint is reported in the registry record. Since the study is single-group, there is also no registered control-group contrast to test.

What is over-dispersion, in general?

General explanation: over-dispersion arises when observed variability is greater than a statistical model assumes. If a model understates variability, its uncertainty estimates can be too small and inferences can appear more precise than warranted. This concept is especially relevant to models for counts or other outcomes with distributional assumptions. The primary endpoint is continuous and summarized by a mean and standard deviation; the registry record does not describe a model or report evidence of over-dispersion. It would therefore be inappropriate to claim that over-dispersion occurred in this study.

What can be said about sample size?

The registered enrollment is 16. Enrollment is not the same as the number analyzed for each endpoint, and endpoint-specific analysis counts are not reported in the registry record. General explanation: the precision of a mean depends on both the number of observations and the variability of those observations. The enrolled total alone cannot establish the precision of the primary endpoint estimate when the number of usable measurements and their spread are unknown.

The planned sample-size justification and statistical plan are not reported in the registry record. Any planning illustration based on a hypothetical effect would not be an observed result and would not establish the study’s actual power. The record does not provide a basis for inferring a design target, an interim analysis, or a prespecified statistical test. The registry lists 0 analyses, so no inferential result is available to explain.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Anti-caries Varnish")
n   <- c(16)
m   <- c(1.7)
sp  <- c(0.7)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Anti-caries Varnish  16  1.700  0.700  1.327  2.073

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures, while the registry entries available for analysis list 0 analyses. The primary endpoint is observed iodine Tmax, but its numerical result is not reported in the registry record. The record does not describe a statistical analysis plan, identify which outcomes were included in formal inference, or state whether any adjustment for multiple comparisons was planned or performed. Consequently, multiplicity procedures cannot be assessed.

General explanation: when several outcomes or hypotheses are tested, the chance of finding at least one apparently notable result can increase if each is assessed independently. Multiplicity methods may be used to control that risk, depending on the study’s goals and prespecified plan. No such method should be assumed for this study. The number of registered outcome measures alone does not show that all were tested or that any particular adjustment was needed or applied.

Missing-data handling is not reported in the registry record. The enrollment of 16 does not establish how many participants had evaluable measurements at each scheduled time or for each outcome. The record does not report reasons for missing observations, rules for excluding measurements, imputation, or sensitivity analyses. Those omissions limit assessment of whether the posted endpoint summary, if available, would represent all enrolled participants or a subset.

The analysis population is also not reported in the registry record. It is therefore not possible to determine from the registry entries whether the intended analysis included all enrolled participants, only those with measurements, or another defined group. No interim analyses or stopping rules are described in the registry record. These unknowns should remain unresolved rather than being filled in by assumptions.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry reports one anti-caries varnish group with 16 participants at risk for serious adverse events and 0 affected. It also reports 16 at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse event terms are listed.

These figures are counts in the registry record. They do not provide event descriptions, timing, severity grading beyond the serious/non-serious grouping, or participant-level detail. The record does not report whether every enrolled participant was included in the safety population or observed for the same duration. The group’s at-risk counts therefore should not automatically be treated as proof of complete follow-up for all enrolled participants.

A report of zero events means no events are recorded in these categories for this group in the registry data; it does not establish that the risk of an event is zero. With no comparator group, the figures do not support a comparative safety estimate. They also do not establish that the varnish caused or prevented any event. The registry record does not report additional information that would permit a fuller safety assessment.

13. What the Result Does, and Does Not, Mean

The record establishes that a completed Phase 2 study enrolled 16 participants and assessed a single topical application of anti-caries varnish in a single-group design. Its stated aim was to characterize iodine and fluoride kinetics in healthy adults. The primary endpoint is observed iodine Tmax, defined as time to maximum serum iodine concentration in hours, with assessments scheduled through 24 hours post-dose.

The primary endpoint’s result is not reported in the registry record. There is no posted mean or standard deviation from which to describe the observed timing or variation in iodine Tmax. No confidence interval, p-value, or other inferential analysis is reported. Thus, the registry record does not establish the size or precision of the primary endpoint estimate.

The single-group design also means there is no registered control-group comparison. The study record cannot provide a comparative estimate of what would have happened under another treatment or no treatment. The absence of a comparator is a design feature, not a numerical finding. It limits the kinds of conclusions that can be drawn even if descriptive pharmacokinetic data were available.

The endpoint is a timing measure, not a direct measure of maximum concentration, dental-caries incidence, or another clinical outcome. Although dental caries is listed as a condition and the intervention is named as an anti-caries varnish, the primary endpoint alone does not answer whether the varnish affects caries. No clinical effectiveness result is reported in the registry record for this analysis.

The registry reports no serious adverse events, other adverse events, or deaths in the listed group, among the reported at-risk counts. Those counts are descriptive and do not demonstrate absence of risk or permit comparison with another group. Taken together, the record describes the study’s design, endpoint, schedule, and listed safety counts, but does not report the primary pharmacokinetic result or a comparative clinical outcome.

14. Why This Trial Matters Statistically

This study is statistically useful to consider because it illustrates the difference between registering a scientific question and posting a result that can be interpreted. The registry defines a specific pharmacokinetic endpoint, states its unit, identifies a mean and standard deviation as summary statistics, and gives a schedule of measurements. Those details clarify the intended focus. However, the endpoint’s numerical result is not reported in the registry record, so the central descriptive estimate and its variability cannot be evaluated.

The single-group design is also instructive. A one-group pharmacokinetic study may be organized around describing measurements after an application, rather than testing a treatment contrast. But design and inference must be kept aligned: without a comparator group, there is no between-group effect estimate. The intervention name and registered condition cannot substitute for a clinical outcome comparison.

The difference between enrollment and analysis population is another important statistical point. The registry lists enrollment of 16, but does not report how many participants contributed to the primary endpoint or how missing measurements were handled. A registered enrollment total cannot by itself show the precision of an estimate, particularly when the endpoint result and its dispersion are absent.

Finally, the record’s safety counts illustrate the importance of interpreting zero counts narrowly. The group has no recorded serious adverse events, other adverse events, or deaths in the listed figures, but these counts are not a controlled comparison and do not prove zero risk. A careful reading separates what is explicitly recorded from what remains unknown: the endpoint definition and design are stated; endpoint results, analytic details, and comparative evidence are not reported in the registry record.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary limitation for statistical interpretation is that the registry record does not report the primary endpoint’s result. Although observed iodine Tmax is defined and its assessment schedule is listed, the mean and standard deviation are not available. Without a numerical estimate, the timing of the observed maximum and its participant-level variability cannot be described.

The design is single-group, with allocation listed as not applicable and masking as none. There is no comparator group, so no between-group estimate can be made from this study record. This also means that descriptive observations after application cannot, by themselves, distinguish intervention-related changes from other influences.

The registered enrollment is 16, but endpoint-specific analysis counts and participant flow are not reported in the registry record. The analysis population, missing-data handling, and reasons for any unavailable measurements are not reported in the registry record. As a result, the completeness and representativeness of endpoint measurements cannot be assessed.

The registry lists 13 outcome measures and 0 analyses. The statistical analysis plan, sample-size justification, inferential procedures, multiplicity approach, and interim analyses are not reported in the registry record. The method used to determine observed Tmax from the scheduled serum measurements is also not reported in the registry record.

Finally, the primary endpoint concerns iodine timing, whereas the stated study aim includes iodine and fluoride kinetics. Numerical results for iodine Tmax and fluoride kinetics are not reported in the registry record. The endpoint is not a clinical caries outcome, and the record does not support a conclusion about clinical effectiveness. The safety figures are limited to the reported group counts and do not provide a controlled safety comparison.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Pharmacokinetics of Advantage Anti-Caries Varnish — NCT04183231.
• Registry record last updated 2020-08-21; status last verified 2020-07.
• Results first posted 2020-08-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT04183231 is a completed Phase 2, single-group study of anti-caries varnish. The registry lists enrollment of 16 and describes a single topical application of 0.4 ml varnish containing 10% PVP-I and 2.5% NaF. The study aim was to characterize iodine and fluoride kinetics in healthy adults.

The primary endpoint is observed iodine Tmax, or time to maximum serum iodine concentration, measured in hours. Scheduled measurements are listed from 0 through 24 hours post-dose. The registry record does not report the primary endpoint’s mean or standard deviation, and lists 0 analyses. There is no comparator group.

The listed safety counts are 0 serious adverse events, 0 other adverse events, and 0 deaths, with 16 at risk in each adverse-event category. These are descriptive registry counts, not comparative estimates. The record does not report the analysis population, missing-data handling, or statistical analysis plan.