Efficacy of an Antibacterial Toothpaste and Patients' Satisfaction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy of an Antibacterial Toothpaste and Patients' Satisfaction (NCT05569850), a randomized na study. The primary outcome is Bacterial Count of Streptococcus Mutans (S. Mutans).

2. Clinical Question

The record also describes secondary aims: assessing participants’ impressions of the toothpastes, including taste and satisfaction, and investigating possible changes in dentin hypersensitivity, plaque formation, and gingival inflammation. The listed secondary outcome measures include Plaque Index, Gingival Index, Dentin Hypersensitivity, and Tooth Colour. Numerical results are posted for Plaque Index and Dentin Hypersensitivity; numerical results for the other listed secondary measures and for satisfaction or taste are not reported in the registry record.

The primary question is about a difference in a measured bacterial count, not a direct measure of clinical disease or patient satisfaction. Interpreting the estimate therefore requires attention to its unit, group definition, uncertainty, and the short stated measurement timeframe. The registry record does not report a threshold for a clinically meaningful change, nor does it report how the bacterial-count result was intended to relate to longer-term outcomes.

3. Trial Design

The registry describes a randomized, double-blind, parallel-group controlled trial. Participants were assigned to one of two toothpaste groups: brushing twice a day with a recently introduced toothpaste or brushing twice a day with a commercially available toothpaste. The record lists the allocation as randomized and masking as double, but does not report the specific randomization method, who was masked, or how masking was maintained.

The listed conditions are caries and gingivitis. Planned enrollment was 100. The record gives a start date of 2022-12-01, primary completion of 2023-07-15, and a completed status. The primary outcome timeframe is 4 weeks. These registry fields describe the planned and recorded trial timeline; they do not by themselves establish how many participants completed each measurement or how long each participant was followed.

For the primary bacterial-count result, the posted group summaries include 46 participants in the recently introduced toothpaste group and 39 in the commercial toothpaste group. The secondary summaries for plaque and dentin hypersensitivity use those same group counts. The record does not explain why these outcome counts differ from planned enrollment, so the reasons for the difference, including any noncompletion or missing measurements, are not reported in the registry record. Safety summaries list 50 participants at risk in each group; that count should be read separately from the outcome-specific counts.

The registry lists University of Bologna as sponsor and the intervention as “Brushing.” It does not report the original sample-size justification, the planned analysis population, the detailed statistical analysis plan, or whether any interim analyses were planned. The posted comparisons are unadjusted recalculations from the group summaries, rather than a reported sponsor analysis. No sponsor analysis is listed in the results record.

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 Bacterial Count of Streptococcus Mutans (S. Mutans), measured over 4 weeks.

The primary endpoint is the bacterial count of Streptococcus mutans (S. mutans) in saliva, expressed as log CFU/ml, with the measurement timeframe listed as 4 weeks. CFU means colony-forming units: colonies grown from a saliva sample are counted as an indicator of the number of viable bacteria in the sample. The registry describes isolating S. mutans using MSTB agar, diluting the saliva sample, culturing the diluted sample, incubating the plates, and identifying colonies by morphology and color.

A bacterial count gives a quantitative measure that can be compared between groups. Reporting the outcome on a logarithmic scale represents differences in bacterial quantity on that scale rather than as a raw count of colonies. The registry specifies the group mean and standard deviation as the summary measures. These describe the average observed count on the stated scale and the spread of individual measurements around that average.

The endpoint is relevant to the trial’s stated objective because it directly measures the quantity of S. mutans in saliva. It is nevertheless a surrogate laboratory measure: by itself, it does not establish changes in caries, gingivitis, symptoms, or satisfaction. The record does not report a threshold for interpreting a difference as clinically important, or a rationale connecting the 4-week bacterial-count measure with later clinical outcomes.

7. Results Posted in the Registry

• Commercial Toothpaste: mean 4.28 versus 4.26 on control; difference 0.02 (95% CI -0.02 to 0.05), standardized effect d = 0.18; z-test p = 0.415.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Plaque Index

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Commercial Toothpaste: mean 0.17 versus 0.10 on control; difference 0.07 (95% CI 0.04 to 0.10), standardized effect d = 0.91; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Commercial Toothpaste than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Dentin Hypersensitivity

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Commercial Toothpaste: mean 0.20 versus 0.19 on control; difference 0.01 (95% CI -0.03 to 0.05), standardized effect d = 0.10; z-test p = 0.646.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Commercial Toothpaste and the control. The interval gives the range of effects that remain compatible with the data.

The secondary results broaden the picture beyond salivary bacterial count. The registry lists outcomes relating to plaque, gingival inflammation, dentin hypersensitivity, and tooth colour. Numerical summaries are posted for Plaque Index and Dentin Hypersensitivity, but numerical results for Gingival Index and Tooth Colour are not reported in the registry record. The record’s broader description also mentions impressions of taste and satisfaction, for which numerical results are not reported.

The overall pattern is not uniform across the posted comparisons: the plaque comparison has a confidence interval that excludes zero, while the dentin hypersensitivity comparison’s interval includes zero. These secondary findings do not overturn or resolve the primary result. They concern different outcomes and cannot be treated as evidence about the primary bacterial-count endpoint. Likewise, the primary result does not determine what the secondary measures show.

Secondary endpoints can be useful for generating hypotheses and describing other dimensions of a trial, but they usually carry less confirmatory weight when there are several outcomes and no reported plan for multiplicity. An unadjusted result does not account for the chance of finding a seemingly notable result among multiple comparisons. The registry record does not report a hierarchy of endpoints, an adjustment method, or a prespecified interpretation of these secondary results.

It is also not clear from the record whether every listed secondary outcome was measured, analyzed, or simply not posted. The number of registered secondary outcomes is four, but the numerical result details available in the registry record cover only two. Without an explanation of the unavailable results or a full analysis plan, the set of posted results may not convey the complete secondary-outcome picture. These limitations make the secondary findings descriptive rather than definitive.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Plaque Index
• Gingival Index
• Dentin Hypersensitivity
• Tooth Colour

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, and the registry summarizes it using means and standard deviations. A mean is the arithmetic average of the observed measurements in a group. A standard deviation describes how much individual observations typically vary around that group’s mean. These summaries give a concise account of the group distributions, but they do not show every participant’s measurement or reveal whether the data include unusual values or skewness.

What does the mean difference describe?

The comparison is expressed as the commercial toothpaste group mean minus the recently introduced toothpaste group mean. A positive estimate therefore means the posted mean is higher in the commercial toothpaste group; a negative estimate would mean it is lower. The estimate of 0.016 is in log CFU/ml, the same scale as the outcome. It is not a percentage change or a raw count difference. No conversion to a raw bacterial count is reported, and none is needed to describe the comparison on the stated scale.

The posted comparison is an unadjusted recalculation from the group summaries. In general, an unadjusted comparison summarizes the observed difference between groups without controlling for other measured characteristics. Randomization is intended to support fair comparison of groups, but the record does not report the randomization procedure, baseline characteristics, or an adjusted analysis. The recalculation should therefore not be described as a model-based or covariate-adjusted result.

How should the confidence interval be read?

A confidence interval gives a range of values reasonably compatible with the observed data under the assumptions of the method used. It communicates uncertainty around an estimate, rather than identifying a set of values that are guaranteed to contain the true difference. The primary interval runs from -0.022 to 0.054. Because it includes zero, the posted data do not rule out no difference on this scale. Its endpoints also indicate that positive and negative differences remain compatible with the data. The registry record does not report a prespecified equivalence margin or a clinical importance threshold, so the interval cannot establish equivalence or determine clinical importance.

What does the p-value add?

The unadjusted recalculated p-value for the primary comparison is 0.415. In general, a p-value describes how unusual data at least as discrepant as those observed would be under a specified null model. It is not the probability that the null hypothesis is true, and it is not a measure of the size or importance of a difference. Read alongside the confidence interval, it indicates that the posted result does not provide strong statistical evidence against a zero-difference null for this comparison. It does not show that the groups are identical.

These interpretations depend on statistical assumptions. For a mean-based comparison, the method relies on the group summaries adequately representing the data and on the uncertainty calculation being appropriate for the sampling distribution. General statistical practice also considers independence of observations and distributional features, including skewness and influential observations. The registry record does not report diagnostic checks or enough individual-level data to assess these features. A standard deviation is a measure of spread, not a guarantee that the underlying data follow a normal distribution.

Why do secondary comparisons need caution?

Several outcomes are listed, and the record does not report a plan for controlling the chance of false-positive findings across multiple comparisons. When many outcomes or comparisons are examined, at least one may appear statistically notable by chance more often than in a single prespecified test. An unadjusted p-value for a secondary endpoint does not account for that broader testing context. The posted secondary comparisons should therefore be treated as descriptive signals rather than isolated confirmation of an effect.

The registry lists Plaque Index, Gingival Index, Dentin Hypersensitivity, and Tooth Colour as secondary outcomes, while numerical result summaries are posted for Plaque Index and Dentin Hypersensitivity. It does not report whether additional outcomes were measured but not posted, why some numerical results are absent, or how the secondary comparisons were prioritized. The original statistical plan, including any multiplicity approach, is not reported in the registry record.

There are also important analysis details that cannot be reconstructed from group means and standard deviations. The record does not report whether the primary comparison used a particular test in the trial’s own analysis, whether measurements at baseline were incorporated, or how missing data were handled. It does not identify an intention-to-treat or per-protocol population. Consequently, the posted recalculated comparison is useful for understanding the reported summaries but cannot substitute for a fully specified analysis of participant-level data.

Finally, statistical evidence and clinical importance are different questions. A p-value and confidence interval describe compatibility and precision under a statistical model. Whether a difference matters to patients or clinical practice depends on outcome context and a threshold for meaningful change. Such a threshold is not reported in the registry record for the bacterial-count endpoint.

11. Confidence Intervals and Precision

Precision describes how tightly the data locate the estimated group difference. The primary mean difference is 0.016 log CFU/ml, with a 95% confidence interval from -0.022 to 0.054. The interval spans values on both sides of zero. It therefore leaves uncertainty about whether the underlying mean difference is slightly negative, close to zero, or positive. The reported point estimate is not a precise declaration that the true difference equals 0.016.

A confidence interval is more informative than a point estimate alone because it displays uncertainty in the scale of the outcome. The interval does not say that there is a 95% probability that the true effect lies between its endpoints. In general, a confidence interval is constructed by a method that, under its assumptions, would contain the true parameter at the stated rate across repeated studies. The registry record does not specify the method used for the posted interval, beyond its characterization as a recalculation from summary statistics.

The interval’s inclusion of zero is consistent with the unadjusted recalculated p-value of 0.415, but neither statistic establishes that the treatments are equivalent. Demonstrating equivalence requires a justified margin defining differences considered sufficiently small, as well as a design and analysis suited to that question. No such margin is reported in the registry record. Nor is a clinical importance threshold reported for the bacterial-count measure.

The outcome summaries include 46 participants in one group and 39 in the other. The record does not explain how these counts relate to planned enrollment of 100, so the potential effect of missing measurements on precision and representativeness cannot be assessed from the registry record. The interval describes statistical uncertainty under its calculation; it does not capture every uncertainty arising from missing data, study conduct, outcome measurement, or reporting.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on the observed effect, not the trial’s original design justification. They are expressed as participants per arm, not as a combined total. For each stated fraction of the observed effect, the columns give the number of participants per arm for 80% power and for 90% power. In plain terms, 80% power is the chance, under the specified assumptions and if the target effect is real, of detecting that effect at the stated significance level. The 90% column represents a higher chance of detecting it under those same assumptions.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is set to the stated fraction of the observed effect. The rows therefore illustrate planning for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. Smaller target effects require more participants because they are harder to distinguish from random variation. A higher desired power also requires more participants, all else being equal.

These calculations are not observed power. They are prospective planning illustrations generated from the effect estimate in the posted comparison. They do not show the probability that the completed trial “had enough power” after observing its results, and they should not be used as evidence that the original trial was designed around these assumptions. The original design assumptions and sample-size justification are not reported in the registry record.

The planning figures depend on the observed effect and the stated simplifying assumptions. If the true effect differs from the observed estimate, or if actual design features differ from equal allocation and the normal approximation, the required sample size could differ. The illustrations do not account for details that are not reported, such as a missing-data allowance or a multiplicity adjustment.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 0.016; pooled standard deviation σ = 0.090.
2. n = 2 × (1.96 + 0.842)² × 0.090² / 0.016² = 493.2, rounded up to 494 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 0.016                      # observed difference in means
sigma <- 0.0896868198937313                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(5569850)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 494 (80% power), 661 (90% power)
 75% of observed effect: n per arm = 877 (80% power), 1,174 (90% power)
 50% of observed effect: n per arm = 1,973 (80% power), 2,642 (90% power)
power.t.test: 494.2 
Simulated power at n = 494 per arm: 0.802 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary endpoint and four secondary outcomes. It does not report whether the trial’s analysis plan controlled for multiplicity across outcomes or comparisons. Multiplicity matters because examining several outcomes can increase the chance that one result appears statistically notable even when there is no underlying difference. A prespecified hierarchy or adjustment can address this issue, but neither is reported in the registry record. The secondary p-values should therefore be read as unadjusted evidence for their individual comparisons, not as confirmatory results across the full set of outcomes.

The registry record also does not report a missing-data strategy, the number of participants with missing measurements, or reasons that the primary and secondary outcome counts are 46 and 39 when planned enrollment was 100. It is not possible from these summaries to determine whether unavailable measurements were unrelated to outcomes or whether their absence could have influenced the estimates. No imputation method, sensitivity analysis, or other missing-data procedure is reported.

The analysis population is not specified. The record does not say whether the trial used an intention-to-treat population, a per-protocol population, or another defined set of participants for the outcome comparisons. Nor does it explain the relationship between the outcome counts and the safety counts, which list 50 participants at risk in each group. The distinct figures may reflect different reporting sets, but the reason is not reported and should not be inferred.

No reported sponsor analyses are listed. The displayed comparison estimates are unadjusted recalculations from posted summary statistics, and the registry does not provide a detailed statistical analysis plan, covariate adjustments, or model diagnostics. These omissions limit assessment of whether analysis decisions were prespecified and how robust the posted comparisons are to alternative reasonable methods.

15. 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.

The serious adverse event summary lists 50 participants at risk in each toothpaste group and zero serious adverse events affecting participants in either group. It also lists zero other adverse events affecting participants in each group, and zero deaths in each group. These are the counts recorded in the registry safety fields.

Zero recorded events in these groups means that the registry reports no such events among the participants listed as at risk during the recorded safety period. It does not establish that an event could not occur, and it does not guarantee that the groups have identical safety profiles. Event counts can be difficult to interpret without details about monitoring, event definitions, duration of observation, and completeness of reporting. Those details are not reported in the registry record.

The safety counts should not be conflated with the outcome-specific sample sizes of 46 and 39. The record does not explain the relationship between these sets of numbers or provide further participant-level safety information. The posted counts describe recorded events; they are not, by themselves, a comparative safety analysis.

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

The primary result describes the average salivary S. mutans count on a log CFU/ml scale at the 4-week timeframe. The observed means were 4.261 in the recently introduced toothpaste group and 4.277 in the commercial toothpaste group. Their reported mean difference was 0.016, with a 95% confidence interval from -0.022 to 0.054 and an unadjusted recalculated p-value of 0.415. The interval includes zero and allows for differences in either direction.

These statistics do not establish that the toothpastes are equivalent, nor do they establish a clinically meaningful difference. Equivalence requires a predefined margin for a difference considered unimportant, and the registry record does not report such a margin. Clinical importance also depends on whether a change in the bacterial-count measure corresponds to an outcome that matters to participants. The record does not report a threshold or establish that connection.

The endpoint is a laboratory measurement of bacteria in saliva, not a direct report of caries, gingivitis, patient satisfaction, or long-term health. The record describes a 4-week measurement timeframe and does not provide later follow-up results. It therefore cannot establish whether the measured counts persist, change over time, or relate to longer-term clinical outcomes.

The numerical comparison is a recalculation from posted group summaries, not a reported adjusted sponsor analysis. The record does not report the original statistical analysis plan, the handling of missing outcome data, or the analysis population. Planned enrollment was 100, while the primary summaries contain 46 and 39 participants; the reason for that difference is not reported. These points limit what can be concluded from the posted result.

In short, the record reports close group means for the primary measure, but the uncertainty interval is not narrow enough to establish a precise equality or a meaningful difference. The result should be understood as a comparison of the observed summaries on the stated measure and timeframe, rather than as a broad conclusion about toothpaste performance or clinical outcomes.

17. Why This Trial Matters Statistically

This trial illustrates why an effect estimate should be read together with its uncertainty. A small point estimate can be compatible with more than one underlying value, and the confidence interval clarifies what directions and magnitudes remain plausible under the calculation. The primary estimate and interval convey more than a binary label based on the p-value alone.

It also highlights the distinction between a statistical comparison and an equivalence claim. A non-significant result does not prove equality. To support equivalence, investigators ordinarily need a prespecified margin and a design and analysis aimed at showing that differences are sufficiently small. The registry record does not report an equivalence margin, so the posted primary result cannot be interpreted as an equivalence finding.

The record provides an opportunity to consider how sample-size planning depends on the effect one aims to detect. The planning illustrations show that smaller target effects require larger per-arm sample sizes under the stated assumptions. Because the figures are based on the observed effect rather than the original design rationale, they are not a substitute for a prospective sample-size justification.

Finally, the result demonstrates the importance of transparent reporting. Planned enrollment, outcome-specific counts, safety counts, unavailable secondary results, missing-data handling, analysis populations, and multiplicity plans all affect interpretation. Several of these details are not reported in the registry record. Clear reporting of those elements helps readers distinguish uncertainty arising from sampling from uncertainty about trial conduct and analysis.

18. 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 registry record gives limited detail about trial conduct and analysis. It identifies the design as randomized, double-blind, and parallel-group, but does not specify how randomization was implemented, who was masked, or how masking was maintained. It also does not provide participant eligibility criteria beyond the listed conditions of caries and gingivitis, baseline characteristics, or a fuller description of the recruited population.

Planned enrollment was 100, whereas the primary and posted secondary outcome summaries use group counts of 46 and 39. The safety fields list 50 participants at risk per group. The record does not explain these different counts, give reasons for missing outcome measurements, or state how missing data were handled. This prevents assessment of whether outcome availability could have influenced the estimates.

The record does not report the original sample-size justification, a detailed statistical analysis plan, the analysis population, or any sponsor-reported analyses. The posted comparisons are unadjusted recalculations from summary statistics. There is no reported multiplicity strategy for the several outcomes, and numerical summaries are not available for all listed secondary measures. These gaps limit confirmation of prespecification and assessment of the complete outcome pattern.

The primary endpoint is a salivary bacterial-count measure at 4 weeks. The registry does not report a clinically meaningful threshold for that outcome, longer-term results, or evidence linking the count difference to clinical outcomes. Patient impressions, including taste and satisfaction, are described as objectives, but numerical results are not reported in the registry record. Thus, the posted results address only part of the trial’s stated scope.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Efficacy of an Antibacterial Toothpaste and Patients' Satisfaction — NCT05569850.
• Registry record last updated 2025-04-29; status last verified 2025-04.
• Results first posted 2025-04-29.
• 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.

22. Record Summary

The registry describes a completed randomized, double-blind, parallel-group trial sponsored by University of Bologna. Planned enrollment was 100, and the groups brushed twice a day with either a recently introduced toothpaste or a commercially available toothpaste. The primary endpoint was mean salivary S. mutans count in log CFU/ml at 4 weeks.

The posted primary means were 4.261 and 4.277, with a mean difference of 0.016 and a 95% confidence interval from -0.022 to 0.054. The unadjusted recalculated p-value was 0.415. Numerical secondary results are posted for plaque and dentin hypersensitivity; other listed secondary results are not reported in the registry record. The record does not report the original sample-size rationale, analysis plan, missing-data handling, or analysis population.