Clinical Efficacy Evaluation of Three Dentifrices: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Efficacy Evaluation of Three Dentifrices (NCT03988374), a randomized phase 2 study. The primary outcome is Mean Within-Treatment Whole-Mouth Score - Gingival Efficacy.

2. Clinical Question

The stated outcome is a gingival efficacy measure scored on a scale from 0-4. Its score definitions range from absence of inflammation to severe inflammation. The clinical question therefore concerns a measured gingival condition over follow-up, rather than a reported result about plaque: although plaque is named among the conditions and in the trial title, the registry record does not provide plaque outcome details in the primary measure description.

3. Trial Design

The registry record describes NCT03988374, titled Clinical Efficacy Evaluation of Three Dentifrices. It is a Phase 2, randomized, triple-masked, parallel-group trial sponsored by Church & Dwight Company, Inc. The three groups are described by dentifrice concentration: 0%, 20% and 35% baking soda. The record reports enrollment of 319. It does not state how participants were recruited or provide their baseline demographic or clinical characteristics.

The trial started on 2018-02-22, had a primary completion date of 2018-08-24, and is listed as completed. The brief summary describes comparison of the dentifrices for their ability to reduce gingivitis and plaque following 6-months of use. The primary outcome timeframe lists baseline, six weeks, 3 months and 6 months. The record does not explain whether every participant was followed at each timepoint or how long participants were observed after their assigned use ended.

Randomization indicates that assignment was intended to be determined by chance, while a parallel design means participants were assigned to a group rather than crossing through multiple dentifrices. The record identifies masking as triple but does not identify which groups of people were masked or describe how masking was maintained. It lists one intervention category, Dentifrices, and supplies no further arm descriptions.

The registry record names three outcome measures and zero analyses. It does not report the randomization procedure, allocation concealment, adherence, protocol deviations or a statistical analysis plan. It also does not state whether the planned enrollment was based on a formal sample-size justification. These details cannot be inferred from the design label or the enrollment figure.

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 Mean Within-Treatment Whole-Mouth Score - Gingival Efficacy, measured over baseline, six weeks, 3 months and 6 months.

The primary endpoint is titled Mean Within-Treatment Whole-Mouth Score - Gingival Efficacy. It is reported as a mean on a scale measured in units on a scale, with standard deviation as the stated measure of dispersion. The timeframe comprises baseline, six weeks, 3 months and 6 months.

The score is based on a Gingival Index with values from 0-4. Its definitions describe increasing signs of gingival inflammation: 0 means absence of inflammation, while the higher categories describe progressively more extensive or severe signs, including redness, edema, hypertrophy and, at the severe end, spontaneous bleeding, congestion or ulceration. The registry record gives separate descriptions for the two mild-inflammation categories and for moderate and severe inflammation.

As general statistical context, a mean can describe the average score across the measured whole mouth within a treatment group, while a standard deviation describes the spread of individual scores around that average. Repeated measurements can describe how group averages vary over follow-up. Those summaries alone do not establish whether groups differ: a between-group contrast and its uncertainty are needed to assess the comparative result.

The registry record does not report any mean scores, standard deviations, changes from baseline, or between-group estimates for this endpoint. It also does not specify how the whole-mouth score was calculated from individual sites or how missing measurements were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a continuous outcome and states that it is summarized as a mean with standard deviation. This describes the intended form of the outcome summary, not a complete statistical analysis plan. No outcome values or analysis results are reported, so the methods can be explained only in general terms and in relation to the information that is registered.

What a mean and standard deviation describe

General explanation: the mean is an average of measured values. The standard deviation describes how dispersed values are around that average. Reporting both can convey the central level and variability of a continuous measure. In this trial, the measure is a whole-mouth gingival score, with the stated scale ranging from 0-4. The registry record does not report the group-specific means or standard deviations, and it does not describe the distribution of scores.

A mean within a treatment group is not the same as a treatment effect. A treatment effect is ordinarily expressed as a contrast between groups, or as a comparison of changes between groups when change over time is the target. A group can show a change from baseline without that change being different from the change in another group. Since no contrasts or changes are reported, the comparative effect cannot be reconstructed from the registry record.

Repeated measurements and comparisons

The endpoint timeframe includes baseline, six weeks, 3 months and 6 months. General explanation: measurements from the same participant over time are related, rather than independent observations. An analysis of repeated measurements may account for that within-participant relationship and may estimate patterns over time. The statistical model, covariance assumptions, handling of baseline and choice of primary comparison are not reported in the registry record. No specific model should therefore be attributed to this trial.

The record's skip note says the primary outcome has several categories or timepoints and was not reduced to one comparison. This leaves the comparative question unresolved in the posted results. A single estimate might focus on one follow-up time, an average across timepoints, or a group-by-time pattern; those choices answer different questions. The registry record does not state which would have been the planned primary contrast. It also does not report estimates for any of these possibilities.

Uncertainty, hypothesis tests and interpretation

General explanation: a confidence interval gives a range of values compatible with the data and the statistical model at a stated confidence level. Its width conveys precision, while the values in the interval convey which effect sizes remain plausible under that analysis. A p-value measures how surprising data at least as incompatible with a null hypothesis would be if that hypothesis and the analysis assumptions held. Neither measure gives the probability that a treatment works, nor does either alone establish practical importance.

No confidence interval, p-value or comparative estimate for the primary endpoint is reported. The significance level mentioned in the registry's planning note is 0.05. That is an assumption for a planning illustration; it is not a reported significance test result and does not establish that the trial's analyses used that threshold.

Dispersion and assumptions

General explanation: a standard deviation summarizes spread, but does not by itself reveal whether a distribution is symmetric, has extreme values or has different variability across groups. If an outcome's variance is larger than expected under a model, over-dispersion can make standard errors too small and confidence intervals too narrow unless the analysis accounts for it. This is a general concern, not a finding about this trial. Distributional diagnostics and any adjustments for dispersion are not reported in the registry record.

The primary measure is an average of a scale whose component scores are defined in ordered categories. The registry record does not explain how site-level or component observations were combined into a whole-mouth score, or how the resulting measure was treated statistically. It is therefore not possible to assess from the record whether the chosen summary and model reflect the score's construction.

Planning illustrations

The registry note says that planning illustrations use the observed effect and a stated fraction of that effect, with a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation. The record does not give the numerical illustrations or identify a trial-specific design justification. It also does not provide an observed effect estimate for the primary endpoint. The planning note should be understood as an assumption-based illustration, not as evidence of observed power, a guarantee of precision or a result from the trial.

General explanation: a sample-size calculation depends on assumptions about the target effect, variability, significance threshold, power and allocation. Changing those assumptions changes the planning requirement. Because the registry record does not report a protocol justification, underlying effect or variability assumptions, readers cannot evaluate whether the enrolled number was selected to detect a particular gingival-score difference.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is recorded across baseline, six weeks, 3 months and 6 months, and the registry's skip note says the outcome has several categories or timepoints and was not reduced to one comparison. The record lists three outcome measures but zero analyses. It does not explain how the trial addressed the possibility of multiple comparisons across outcome measures, timepoints or the three dentifrice groups. A multiplicity adjustment, hierarchy of outcomes or prespecified testing strategy is not reported in the registry record.

General statistical context: when several hypotheses are tested, the chance of at least one apparently unusual result can increase if each is assessed independently at the same threshold. Prespecifying a primary contrast or using a suitable adjustment can help clarify interpretation. This general point does not establish that the trial did or did not use any such approach; the registry record does not say.

Information about missing data is also not reported in the registry record. It does not state whether participants missed visits, withdrew, stopped using a dentifrice or had incomplete outcome measurements. The record does not describe imputation, complete-case analysis, sensitivity analyses or other missing-data methods. The number enrolled should not be treated as the number analyzed for the primary outcome.

Analysis populations are not described. The registry record does not identify an intention-to-treat, per-protocol or safety population, nor explain exclusions from any analysis. Without this information, it is not possible to determine which participants would contribute to a treatment-effect estimate or how departures from assigned treatment would be handled. These omissions limit assessment of the analysis, independently of the absence of numerical outcome results.

11. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry record lists serious adverse events for each dentifrice group. For the 0% Baking Soda Dentifrice group, 0 serious events are listed among 103 participants at risk. For the 20% Baking Soda Dentifrice group, 0 are listed among 105 at risk. For the 35% Baking Soda Dentifrice group, 0 are listed among 107 at risk. The record also lists 0 deaths in each group.

For other adverse events, the record lists 4 affected participants among 103 at risk in the 0% group, 17 among 105 at risk in the 20% group and 2 among 107 at risk in the 35% group. These counts describe the registered safety entries; they do not establish that events were caused by a dentifrice. The registry record does not provide event names, severity details for the other events, exposure-adjusted summaries, statistical comparisons or an explanation of collection and coding procedures.

General statistical context: a count is not the same as an estimate of comparative risk, and a zero count does not demonstrate that an event cannot occur. Interpretation depends on event definitions, observation time, ascertainment and the analysis population. No serious-event terms are listed in the registry record. The available entries support a descriptive reading only, not a conclusion that one group had a safer profile.

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

The registry record establishes that a randomized, triple-masked, parallel-group Phase 2 trial evaluated dentifrices containing 0%, 20% and 35% baking soda. It identifies a mean within-treatment whole-mouth gingival score as the primary endpoint and gives its scale and follow-up timepoints. It also reports enrollment of 319 and descriptive adverse-event counts. These registry entries describe the trial's stated question and some registered characteristics.

The record does not report the primary endpoint values, a comparison among groups, uncertainty estimates or statistical tests. It therefore does not show how gingival scores changed in any group or whether observed changes differed between groups. The trial title and summary describe an evaluation of gingivitis and plaque, but they are not results. The primary measure description does not give numerical plaque findings.

General statistical context: evidence about an effect requires an estimate of the contrast of interest, together with information about its uncertainty and the analysis that produced it. A study design, enrollment number or planning assumption cannot substitute for those results. Likewise, counts of adverse events without comparative analysis do not establish a causal safety difference.

The posted safety entries list zero serious adverse events and zero deaths in each group, alongside other adverse-event counts. Those entries should be read as registry-recorded counts rather than proof that no other events occurred or that the groups are equivalent. The event definitions and collection details are not reported.

Because the registry record does not report outcome analyses or an analysis plan, it is not possible to assess the magnitude, precision or robustness of the comparative result. No conclusion about whether a dentifrice is effective, ineffective, superior or equivalent follows from the information recorded. The appropriate interpretation is limited to what the record documents and to the gaps it leaves.

13. Why This Trial Matters Statistically

This trial is statistically notable for a gap between a clearly identified comparative design and the absence of reported primary outcome analyses. Randomized parallel groups can support comparisons when outcomes, contrasts and analysis methods are reported. In this record, the primary gingival endpoint and its repeated timepoints are specified, but no numerical estimates or analyses are listed.

Repeated measurements raise a meaningful analysis question. Baseline and follow-up scores can be described separately, but a comparative conclusion requires clarity about how change and between-group differences were handled. The registry record does not identify a primary timepoint or contrast, nor does it state how measurements from the same participant over time were modeled. This makes it difficult to connect the registered endpoint to a single interpretable effect estimate.

Multiplicity also matters when several timepoints, outcomes or group comparisons may be considered. The record lists three outcome measures and indicates that the primary outcome has several categories or timepoints, but does not report a testing strategy. Without an analysis plan or results, readers cannot tell how the investigators distinguished planned comparisons from exploratory ones.

The safety information illustrates a separate statistical distinction: counts are descriptive, while comparative safety claims require context such as event definitions, follow-up, denominators and an appropriate analysis. Although at-risk counts are recorded for each group, further details needed to assess comparability are not reported.

Finally, the planning note describes assumptions for sample-size illustrations, but does not supply numerical planning outputs or a trial-specific justification. This underscores why planning assumptions, observed enrollment and analyzed results answer different questions. The registry record supports a description of the study design, but not an assessment of the precision or strength of its comparative findings.

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 main trial-specific limitation for interpretation is that the registry record does not report numerical results for the primary gingival endpoint. It provides no group means or standard deviations, no changes from baseline, and no between-group estimates. Confidence intervals and p-values are also not reported. The comparative result and its precision therefore cannot be assessed.

The outcome is specified across baseline, six weeks, 3 months and 6 months, but the record does not identify one primary follow-up contrast or explain how repeated measurements were analyzed. It does not describe the derivation of the whole-mouth score from the Gingival Index observations. Although plaque appears in the title, condition list and study summary, plaque outcome results are not described in the primary measure information.

The registry record does not report detailed eligibility criteria, participant characteristics, adherence, withdrawals or protocol deviations. It also does not state which analysis populations were used or how missing outcome data were handled. These omissions prevent evaluation of who contributed to the primary analysis and whether missingness or deviations could affect the estimates.

The record identifies three outcome measures and zero analyses, but does not provide a statistical analysis plan or a strategy for multiple outcomes, timepoints or group comparisons. The planning note describes general assumptions for sample-size illustrations, yet no numerical illustrations or trial-specific sample-size justification are reported. The record also does not specify the roles covered by triple masking or how masking was maintained.

Safety reporting is limited to group-level counts. Event definitions, individual event details, collection procedures and comparative analyses are not reported. These limitations are specific to the information available in the registry record and do not establish that the unreported procedures or analyses were absent from the full study documentation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Clinical Efficacy Evaluation of Three Dentifrices — NCT03988374.
• Registry record last updated 2021-08-23; status last verified 2021-04.
• Results first posted 2021-08-23.
• 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

NCT03988374 is a completed Phase 2 randomized, triple-masked, parallel-group trial sponsored by Church & Dwight Company, Inc. It enrolled 319 and compared dentifrices containing 0%, 20% and 35% baking soda. The study started on 2018-02-22 and its primary completion date is 2018-08-24.

The primary endpoint is a mean within-treatment whole-mouth gingival score on a scale from 0-4, measured at baseline, six weeks, 3 months and 6 months. The registry record lists three outcome measures and zero analyses. It does not report numerical primary outcome results, between-group estimates or their uncertainty.

The adverse-event entries list zero serious events and zero deaths in each group, with other adverse events affecting 4 participants in the 0% group, 17 in the 20% group and 2 in the 35% group. Event details and comparative safety analyses are not reported. The record supports description of the trial design and registered safety counts, but not a quantitative conclusion about comparative efficacy or safety.