Clinical Evaluation of the Efficacy of a Marketed Dentifrice on Plaque and Gingivitis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Evaluation of the Efficacy of a Marketed Dentifrice on Plaque and Gingivitis (NCT03214406), a randomized na study. The primary outcome is Within-Treatment Whole-Mouth Differences (vs Baseline) - Gingival Efficacy.

2. Clinical Question

The clinical question is whether the gingival scores recorded during this study changed from baseline in either assigned group. The primary outcome is described as a mean change in score, measured in units on a scale, rather than as a count of people with gingivitis. The scale ranges from 0 to 4, with higher categories describing progressively more extensive or severe signs of inflammation.

The summary says gingivitis, bleeding, and plaque were evaluated at Baseline and after 4-, 8-, and 12-weeks of product use, with a final evaluation at 16 weeks after the return to the pre-study hygiene regimen. The primary outcome timeframe is 16 weeks. The registry record does not report the numerical outcome at that time, so the intended question can be described, but the size and direction of any observed change cannot be established from the record.

3. Trial Design

This completed study is recorded as randomized, parallel-group, and triple-masked. The summary describes it as double blind, so the registry record contains different masking descriptions. It does not explain the discrepancy or specify which parties were masked. The study is listed as phase NA. Church & Dwight Company, Inc. is the sponsor.

The registry record gives enrollment as 181. Its brief summary says approximately 160 subjects were expected to complete; these are different descriptions, and the record does not explain their relationship. The summary says subjects were randomly assigned to the test product or control based on baseline mean whole-mouth plaque and gingival scores and age. Further detail about the allocation procedure is not reported in the registry record.

Both groups were assigned to brush 2X daily with their respective dentifrice for 12 weeks. The arm descriptions then specify return to the pre-study hygiene regimen for 4 weeks, with final evaluation at 16 weeks. The summary describes evaluations at baseline and after 4-, 8-, and 12-weeks of product use, as well as the final evaluation. The registry record reports that the study began on 2010-02-08, reached primary completion on 2010-08-03, and is completed.

The summary calls the study Institutional Review Board-approved. Detailed eligibility criteria, recruitment methods, allocation concealment, adherence procedures, and rules for discontinuing assigned products are not reported in the registry record. Those omissions limit how fully the conduct of the trial can be reconstructed from the record alone.

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

Reasons for not completing this period:

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 Within-Treatment Whole-Mouth Differences (vs Baseline) - Gingival Efficacy, measured over 16 weeks.

The primary endpoint is the within-treatment whole-mouth difference from baseline in gingival score at 16 weeks. It is described as a mean, with standard deviation as the measure of dispersion, and its unit is score units. The score is based on the Gingival Index, which ranges from 0 to 4. A score of 0 represents absence of inflammation; the higher score descriptions identify increasingly extensive signs, including changes in color or texture, redness, edema, hypertrophy, and, in the most severe category, spontaneous bleeding, congestion, or ulceration.

A continuous index can describe changes across the scale rather than reducing observations to a yes-or-no classification. The registry record’s focus on change from baseline means the intended endpoint concerns how the group’s average score at the specified follow-up differs from its baseline average. The scale definitions give the clinical meaning of the score, but the registry record does not report a threshold for a clinically important change.

The final assessment was scheduled at 16 weeks, after 12 weeks of assigned dentifrice use and 4 weeks back on the pre-study hygiene regimen. The registry record does not report numerical baseline or follow-up means, standard deviations, or mean changes for this endpoint. It therefore does not establish the size or direction of change in either treatment group.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: each observation is a Gingival Index score on a scale ranging from 0 to 4, and the registered summary measure is the mean. The registry record names standard deviation as the measure of dispersion. A mean describes the central average of a group’s scores, while a standard deviation describes how spread out individual scores are around that average. Neither statistic is reported numerically for the primary endpoint in the registry record.

What does a change from baseline represent?

A change-from-baseline endpoint compares a follow-up score with a baseline score. For a group, the mean change describes the average movement in scores over that interval. The direction has meaning because the scale’s lower category is absence of inflammation and higher categories describe more extensive signs. However, the record gives no mean change, so it does not show whether scores moved upward or downward, or by how much.

Within-group change is not the same as a randomized comparison between groups. Each group can change over time for reasons that affect both groups, including the passage of time and study participation. A direct comparison would estimate the difference between the groups’ outcomes or changes. Random assignment supports the planned comparison, but the registry record does not report a numerical between-group estimate for the primary endpoint. The outcome title describes within-treatment differences versus baseline, and should not be interpreted as proof that a comparison between products was reported.

What would a confidence interval add?

In general, a confidence interval expresses the uncertainty around an estimated effect. A narrower interval indicates greater precision, while a wider interval indicates less precision. Its interpretation depends on the estimate and the analysis that produced it. No confidence interval for the primary outcome is reported in the registry record, so the precision of any change or treatment contrast cannot be assessed.

How should repeated measurements be considered?

The summary describes evaluations at baseline and after 4-, 8-, and 12-weeks of product use, plus a final evaluation at 16 weeks. Repeated measurements from the same participant are related rather than independent. In general, an analysis of repeated observations needs to account for that dependence; treating each measurement as unrelated can misstate uncertainty. The registry record does not report the statistical model or method used to handle the repeated measurements, and it does not give numerical results for the intermediate time points.

The primary timeframe is 16 weeks, after the assigned product period and the specified return to the pre-study hygiene regimen. This endpoint therefore addresses the score at the final assessment, not solely the score at the end of assigned product use. The record does not explain how the 16-week change was estimated or whether measurements from earlier visits contributed to that estimate.

What do the design and analysis details tell us?

Randomization assigns participants to groups by chance, which is intended to support fair comparisons by reducing systematic differences at the outset. The summary adds that assignment was based on baseline mean whole-mouth plaque and gingival scores and age. The registry record does not describe the random sequence, concealment of assignments, or the analysis model. It labels masking as triple, while the summary says double blind, without resolving the difference.

The registry record identifies standard deviation for the continuous endpoint but does not provide group means or standard deviations. It lists 0 analyses, so no inferential method, model, adjustment, or test can be identified from the registered analysis information. The absence of a reported analysis is not evidence that a particular method was or was not used outside the registry record.

The record also states assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Such illustrations are planning calculations, not observed power and not trial results. The registry record does not report the sample-size illustration values in the registry record for this analysis, and the primary outcome itself is not reduced to a single comparison. Those assumptions therefore do not establish the study’s original design rationale or provide evidence about the observed treatment effect.

Over-dispersion is a general concern when count data vary more than a simple model expects, because it can make standard errors too small if ignored. It is not a stated feature of this continuous Gingival Index endpoint, and the registry record does not identify an over-dispersion method. No particular statistical technique should be attributed to this study without a reported analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 3 outcome measures and 0 analyses. It also states that the primary outcome has several categories or time points and was not reduced to one comparison. This means the record does not identify a single reported numerical contrast that can be interpreted as the primary statistical result. The outcome title specifies the 16-week timeframe, but results for that measure are not reported in the registry record.

When a study examines multiple outcomes, time points, or comparisons, the chance of finding an apparently notable result can increase if each is tested separately. In general, multiplicity methods can address that issue, but the registry record does not report whether an adjustment was planned or used. It does not report a hierarchy of outcomes or comparisons, either. No claim about control of multiplicity can therefore be made.

Information about missing data is also limited. The record gives enrollment as 181 and says approximately 160 subjects were expected to complete, but it does not report the number who completed, the reasons for any missing measurements, or how missing values were handled. It does not describe an imputation method or a sensitivity analysis.

The analysis population is not reported in the registry record. It does not specify whether analyses included all randomized subjects, only subjects with observed follow-up, or another defined population. The safety record gives group-specific numbers at risk, but those figures do not define the population used for the primary efficacy analysis. Without analysis-set definitions and missing-data details, the relationship between enrollment and any outcome estimate cannot be assessed.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry record reports 0 serious adverse events in the Arm & Hammer Advance White Brilliant Sparkle group, with 88 at risk. It reports 0 serious adverse events in the Crest Cavity Protection Regular Toothpaste group, with 93 at risk. The recorded counts for other adverse events are also 0 in each group, with the same respective numbers at risk.

These are reported counts for the groups described in the safety record. They do not by themselves show how safety events were collected, how long each person was followed for safety, or whether every participant contributed complete safety information. Those details are not reported in the registry record. A zero reported count should be read as the registry’s count, not as proof that an event was impossible or that no event could have occurred outside the recorded data.

Death information is not reported in the registry record. The record does not provide further event descriptions or a breakdown by time of occurrence. These figures are safety summaries and do not provide evidence about the primary Gingival Index endpoint.

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

The trial record describes a randomized comparison of two dentifrices and specifies a primary outcome: mean within-treatment change from baseline in whole-mouth Gingival Index at 16 weeks. It also provides the score’s range and category descriptions, the planned brushing schedules, and the final assessment timing. These details establish what the study intended to examine.

The registry record does not report numerical estimates for the primary endpoint or a direct comparison between the groups. It therefore cannot show the observed direction or size of change, how precisely any effect was estimated, or whether the groups differed. The absence of reported results is not evidence that the products had the same effect, nor does it establish that one had a larger effect.

The design can be described without treating it as a result. Random allocation and masking are features of how a study is organized; they do not on their own determine what the observed data show. The masking descriptions also differ within the record, and the reason for that difference is not reported.

The score categories offer a framework for interpreting a numerical result, but no threshold for an important change is reported. Even if an estimate were available, its statistical uncertainty and clinical meaning would need to be considered separately. The record does not contain the estimates needed to make either assessment for the primary endpoint.

Accordingly, the statistical meaning of this record is limited to the stated question, outcome definition, design, and reported safety counts. It does not support a conclusion about comparative efficacy or a treatment recommendation.

13. Why This Trial Matters Statistically

This study illustrates why a clearly named endpoint and a completed trial status are not enough to interpret a clinical comparison. The record identifies a continuous gingival score, its scale, a baseline reference, and a final assessment at 16 weeks. But without numerical arm results and an estimate of the comparison, readers cannot assess the size or precision of the primary outcome.

It also highlights the distinction between within-group change and a between-group effect. A change from baseline in one arm describes what happened over time in that arm. The randomized comparison asks whether outcomes differed between assigned groups. These are related but distinct questions, and the endpoint title’s within-treatment language does not itself supply the comparative estimate.

Repeated measurement timing matters as well. The summary describes observations during product use and a final assessment after return to the pre-study hygiene regimen. Interpretation depends on which visit addresses the question and how the correlated measurements are handled. The registry record names the final timeframe but does not describe the analysis method.

Finally, this record shows why documentation gaps should be kept separate from findings. The record includes different masking descriptions, does not report the analysis population or missing-data procedures, and lists 0 analyses. These are limits on interpretation, not evidence that a particular procedure was or was not used. Reporting those distinctions helps readers avoid treating study design labels or zero reported events as substitutes for efficacy results.

14. 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 principal limitation for interpreting this trial from the registry record is the absence of numerical primary-outcome results. Arm-level means, standard deviations, changes from baseline, and between-group estimates are not reported. Confidence intervals and test results are also not reported, so neither the magnitude nor the precision of the outcome can be evaluated.

The registry record gives different masking descriptions: triple masking in the design field and double blind in the summary. It does not explain the discrepancy or identify who was masked. The summary says random assignment was based on baseline mean whole-mouth plaque and gingival scores and age, but further details of the allocation method are not reported.

The primary outcome is described at 16 weeks, after the product-use period and return to the pre-study hygiene regimen. Numerical outcomes for intermediate visits are not reported in the registry record, and the record does not describe how repeated measurements were analyzed. The potential clinical importance threshold for changes in the Gingival Index is also not reported.

Although enrollment is listed as 181, the summary describes approximately 160 subjects to complete. The record does not explain this difference or report completion, missing measurements, reasons for missingness, analysis populations, or missing-data methods. The registry record lists 3 outcome measures and 0 analyses and notes that the primary outcome has several categories or time points not reduced to one comparison. It does not describe a statistical plan or multiplicity approach. These limitations prevent a full appraisal of the analysis and its uncertainty.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Clinical Evaluation of the Efficacy of a Marketed Dentifrice on Plaque and Gingivitis — NCT03214406.
• Registry record last updated 2021-05-11; status last verified 2021-04.
• Results first posted 2019-07-23.
• 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.

18. Record Summary

NCT03214406 is a completed randomized, parallel-group study sponsored by Church & Dwight Company, Inc. It compared Arm & Hammer Advance White Brilliant Sparkle with Crest Cavity Protection Regular Toothpaste. The summary describes brushing 2X daily for 12 weeks, followed by a return to the pre-study hygiene regimen for 4 weeks, with a final evaluation at 16 weeks.

The primary outcome is mean within-treatment change from baseline in whole-mouth Gingival Index at 16 weeks. The scale ranges from 0 to 4. The registry record lists enrollment as 181, while the summary describes approximately 160 subjects to complete. Masking is described as triple in one field and double blind in the summary.

Numerical primary-outcome results and statistical analyses are not reported in the registry record. The safety record reports 0 serious and 0 other adverse events in each group; death information is not reported.