Clinical Study Investigating the Efficacy of a Mouthwash in Providing Long Term Relief From Dentinal Hypersensitivity: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Study Investigating the Efficacy of a Mouthwash in Providing Long Term Relief From Dentinal Hypersensitivity (NCT02226562), a randomized phase 2 study. The primary outcome is Mean Change From Baseline in Schiff Sensitivity Score at Week 8.

2. Clinical Question

The registry describes an eight-week study with efficacy and safety assessments at baseline, four weeks, and eight weeks. It lists a randomized, two-treatment-arm, parallel design and describes the examiner as blind to treatment. The primary question is therefore about the difference in average change on a defined clinical measure over the study period, not about every aspect of participants’ experience or about outcomes beyond the recorded follow-up.

3. Trial Design

This was a completed Phase 2, randomized, single-centre, parallel-group study. The registry record gives an enrollment of 191. Its brief description specifies two treatment arms and an eight-week study period, with assessments at baseline, four weeks, and eight weeks. Allocation was described as stratified by the maximum baseline Schiff Sensitivity Score of the two selected test teeth. The registry lists single masking and separately describes the study as examiner blind.

One group used a potassium nitrate and sodium fluoride mouthwash in addition to standard fluoride dentifrice; the other used standard fluoride dentifrice alone. The listed mouthwash contained 3.0% weight by weight potassium nitrate and 0.02% sodium fluoride. The comparator dentifrice contained 1000 ppm fluoride as sodium monofluorophosphate. The primary efficacy analysis population was defined as randomized participants who received at least one dose and contributed at least one post-baseline efficacy assessment.

The posted primary outcome is mean change in Schiff Sensitivity Score from baseline to week 8. Four additional outcomes have posted numerical results: Schiff score change at week 4 and tactile-threshold change at weeks 4 and 8, along with a week-4 and week-8 visual rating scale outcome listed among the secondary outcomes. Numerical results for the visual rating scale outcomes are not reported in the registry record. The record lists six outcome measures and one analysis, and contains a sponsor-reported ANCOVA result for the primary comparison. Further detail about the study’s original sample-size justification, full statistical analysis plan, and conduct of interim analyses is not reported in the registry 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The primary population for efficacy assessment was intent-to-treat (ITT) population.The ITT population comprised of participants, who were randomized, received at least one dose of study treatment and provided at least one post-baseline assessment of efficacy.

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 Change From Baseline in Schiff Sensitivity Score at Week 8, measured over Baseline to 8 week.

The primary endpoint is mean change from baseline to week 8 in Schiff Sensitivity Score. The examiner assessed each tooth’s response to an evaporative air stimulus on a scale from 0 to 3. A score of 0 indicates no response; 1 indicates a response without a request to stop the stimulus; 2 indicates a response accompanied by a request to stop or movement away from the stimulus; and 3 indicates a response described as painful with a request to stop. The registry describes a reduction in score as an improvement in sensitivity.

Using change from baseline focuses the comparison on how the measured response shifted during follow-up, rather than solely on the score at the final visit. The week-8 timing captures the endpoint at the end of the study’s stated eight-week period. As a continuous score, the outcome can be summarized with group means and a mean difference, retaining information about the size and direction of changes rather than reducing responses to categories such as improved or not improved.

The measure is an examiner-assessed response to a specified stimulus. It does not directly capture every dimension of dentinal hypersensitivity, and the registry record does not establish that a change of any particular size is meaningful to every participant. Interpretation should therefore remain tied to this scale, its scoring rules, the recorded follow-up, and the analysis population.

7. Results Posted in the Registry

• Dentifrice Alone: mean -0.37 versus -1.47 on control; difference 1.10 (95% CI 0.92 to 1.28), standardized effect d = 1.74; z-test p = <0.001.

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.

Mean Change From Baseline in Schiff Sensitivity Score at Week 4

• 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:
  • Dentifrice Alone: mean -0.31 versus -0.94 on control; difference 0.63 (95% CI 0.45 to 0.81), standardized effect d = 0.99; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Dentifrice Alone than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Mean Change From Baseline in Tactile Threshold at Week 8

• 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:
  • Dentifrice Alone: mean 3.74 versus 31.32 on control; difference -27.58 (95% CI -33.78 to -21.38), standardized effect d = -1.27; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dentifrice Alone than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Mean Change From Baseline in Tactile Threshold at Week 4

• 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:
  • Dentifrice Alone: mean 0.74 versus 14.11 on control; difference -13.37 (95% CI -17.74 to -9.00), standardized effect d = -0.87; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dentifrice Alone than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Across the secondary outcomes with numerical results posted, the overall pattern is aligned with the primary Schiff score finding: average change is in the direction of greater sensitivity reduction in the dentifrice-plus-rinse group than in the dentifrice-alone group. The posted tactile-threshold outcomes also show larger increases in the rinse group. This cross-measure consistency is supportive context, but it does not turn the secondary outcomes into additional primary evidence.

The registry lists visual rating scale outcomes at both assessment times, but their numerical results are not reported in the registry record. The posted secondary results therefore do not cover every secondary outcome listed. In addition, the registry lists no sponsor-reported analyses for the secondary outcomes; their comparisons are unadjusted recalculations from the posted summaries.

General statistical explanation: testing several outcomes and time points creates multiple opportunities to observe small p-values by chance, even if no effect exists for any of the corresponding hypotheses. Adjustment procedures or a prespecified hierarchy can help control the interpretation of a family of tests, but the registry record does not report a multiplicity plan. The secondary p-values should consequently be regarded as exploratory or supportive rather than as independent confirmatory findings.

The secondary outcomes also measure different aspects of sensitivity, so their numerical changes are not directly interchangeable. The Schiff score is an examiner-rated response to air stimulation, while tactile threshold and visual rating scale are distinct measures. Agreement in direction can strengthen the coherence of the descriptive pattern, but does not establish that the measures capture identical effects or that the results extend beyond the assessment times recorded.

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

• Mean Change From Baseline in Schiff Sensitivity Score at Week 4
• Mean Change From Baseline in Tactile Threshold at Week 8
• Mean Change From Baseline in Tactile Threshold at Week 4
• Mean Change From Baseline in Visual Rating Scale (VRS) at Week 8
• Mean Change From Baseline in VRS at Week 4

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a numerical score, and the registry reports mean change from baseline. Group means make the average direction and magnitude of change visible. A mean difference then compares those averages. Because lower Schiff scores indicate less sensitivity on the registry’s scale, negative mean changes represent reductions, while the sign of a between-group difference depends on which group is subtracted from which.

What does the reported ANCOVA represent?

The registry identifies analysis of covariance (ANCOVA) for the primary comparison and reports a net mean difference, confidence interval, and p-value. In general, ANCOVA compares groups on an outcome while accounting for specified covariates in a statistical model. This can be useful in randomized trials when the analysis aims to adjust for baseline or other prespecified measurements. The exact covariates and full model specification are not reported in the registry record, so the reported ANCOVA cannot be reconstructed in full from the listed results alone.

The sponsor’s reported primary estimate is -1.10, with a 95% confidence interval from -1.28 to -0.92 and p < 0.001. The separate recalculation from the posted arm summaries is unadjusted: it compares the displayed group means without reproducing the sponsor’s model. In the reverse group order it gives a mean difference of 1.1 and p < 0.001. The sign reversal reflects the order of subtraction, not a conflicting direction of result. The registry does not flag a discrepancy between the posted summaries and sponsor analysis.

How should standard errors and standard deviations be distinguished?

The primary outcome reports least-squares means with standard errors. A standard error describes uncertainty in an estimated mean; it is not a description of the spread of individual participant scores. The secondary outcomes report means with standard deviations. A standard deviation describes variability among observations, rather than the precision of the estimated mean. Keeping these measures distinct matters when judging whether a group mean is estimated precisely or whether participants’ values vary widely.

The recalculated primary comparison uses an approximate pooled standard deviation derived from the standard errors and group sizes. It is therefore an approximation based on posted summary information, not a replacement for individual-level variability or for the adjusted ANCOVA. The registry’s sponsor-reported model remains the relevant reported analysis for the primary outcome. The recalculated p-value and comparison are useful as a check on the displayed summaries, but they answer the unadjusted comparison rather than reproducing every aspect of the sponsor’s analysis.

What do confidence intervals and p-values add?

A confidence interval communicates uncertainty around an estimated contrast by giving a range of values compatible with the data and model. Its width is informative about precision: narrower intervals indicate less uncertainty about the estimated contrast, all else equal. A p-value measures how incompatible the data are with a specified null hypothesis under the test assumptions; it is not the probability that the null hypothesis is true, nor a measure of clinical importance. The reported primary interval and p-value should be interpreted together with the effect estimate, outcome scale, population, and analysis model.

General statistical explanation: models depend on their assumptions, including appropriate handling of the outcome distribution, covariate relationships, and dependence among observations. The registry record does not report diagnostics or enough detail to assess all model assumptions. It also does not report the full missing-data method, the handling of deviations from the intended treatment, or the original protocol’s analysis plan. These absences limit independent assessment of analytic choices.

Why are the secondary recalculations different in status?

The numerical secondary results are accompanied by summary statistics and unadjusted comparisons, but no sponsor-reported analyses are listed for those outcomes. Their recalculated p-values do not reflect an adjustment for examining multiple endpoints or assessment times. General statistical explanation: when many hypotheses are tested, the chance of at least one apparently unusual result can increase, so isolated p-values from a collection of analyses warrant more caution than a prespecified primary test. The registry does not report a multiplicity strategy, making the secondary results best read as descriptive and supportive.

None of the recalculated planning figures represent the number of participants actually enrolled, and they do not indicate the trial’s observed power. They are illustrations based on the observed effects and stated planning assumptions. The trial’s own original sample-size justification is not reported in the registry record.

11. Confidence Intervals and Precision

The sponsor-reported 95% confidence interval for the primary net mean difference extends from -1.28 to -0.92. Its limits are relatively close to the point estimate of -1.10, indicating that the estimated average contrast is more precisely localized than it would be with a much wider interval. The interval remains on the negative side of zero in the sponsor’s contrast direction. This is consistent with the reported p-value of < 0.001 for the primary ANCOVA analysis.

Precision is not the same as clinical importance. The interval describes uncertainty in the estimated average difference on the Schiff scale under the analysis model; it does not determine whether participants would notice or value a difference of that size. The registry record does not report a threshold for a clinically important difference, so such a threshold cannot be used to interpret the interval.

The arm summaries report standard errors of 0.065 for each primary group mean. These quantify the precision of the estimated means, not the range of individual responses. The sponsor’s adjusted interval and the unadjusted recalculation are based on different analyses, so their estimates should not be treated as interchangeable. The unadjusted comparison is based on posted summaries, while ANCOVA is the sponsor-reported primary analysis.

Confidence intervals also do not account for every uncertainty relevant to interpretation. They rely on the model and data used for the analysis; they do not resolve concerns about missing data, measurement, masking, or generalizability. The registry record does not report enough detail to evaluate all of those issues. The interval should therefore be read as statistical precision for the primary estimated contrast, not as a complete statement of uncertainty about the study’s broader implications.

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 planning figures are participants per arm, not total events. They are illustrations based on the observed effect rather than the trial’s original design calculation. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set to the stated fraction of the observed effect. The trial’s own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column gives the estimated participants per arm under which the specified planning method would have an 80% chance of detecting the chosen effect, if the assumptions hold. The 90% power column uses a higher probability of detecting that effect and consequently generally calls for more participants per arm. For example, planning for 75% of the observed primary effect gives 10 participants per arm for 80% power and 13 participants per arm for 90% power. Planning for 50% of that observed effect gives 21 participants per arm for 80% power and 28 participants per arm for 90% power.

Smaller effects are harder to distinguish from random variation, so detecting a smaller effect generally requires more participants. The displayed figures change with the chosen fraction of the observed effect; they are not a recommendation for a future study and do not establish that the trial was adequately or inadequately sized. This is not observed power: it is a planning illustration calculated from the observed effect and stated assumptions, not a measure of the probability that the completed trial’s result was correct.

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 = 1.100; pooled standard deviation σ = 0.634.
2. n = 2 × (1.96 + 0.842)² × 0.634² / 1.100² = 5.2, rounded up to 6 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 <- 1.1                      # observed difference in means
sigma <- 0.633541632412583                     # 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(2226562)
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 = 6 (80% power), 7 (90% power)
 75% of observed effect: n per arm = 10 (80% power), 13 (90% power)
 50% of observed effect: n per arm = 21 (80% power), 28 (90% power)
power.t.test: 6.3 
Simulated power at n = 6 per arm: 0.771 (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. Analyses Reported by the Sponsor

The registry reports the sponsor’s primary analysis as ANCOVA, with a net mean difference of -1.10, a 95% confidence interval from -1.28 to -0.92, and p < 0.001. That is the analysis to use when describing the sponsor-reported primary result. Its group ordering gives a negative estimate, consistent with the greater reduction in Schiff score in the dentifrice-plus-rinse arm.

The unadjusted recalculation from the arm summaries gives a mean difference of 1.1 when expressed as dentifrice alone minus dentifrice plus rinse, with p < 0.001. The opposite sign arises from reversing the group order. The recalculation does not reproduce the covariate adjustment in ANCOVA and should not replace the reported model. The registry does not flag a discrepancy between the calculations and the sponsor’s analysis; the recalculation is best understood as a summary-statistic check that is directionally consistent with the sponsor result.

The sponsor-reported analysis does not by itself reveal the full model specification. The covariates, detailed missing-data handling, and other elements needed to reproduce the ANCOVA are not reported in the registry record. Accordingly, the estimate and interval can be reported as recorded, while detailed evaluation of the model choices remains limited by the available record.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and five secondary outcomes, with assessments at different times. It reports one sponsor analysis, the primary ANCOVA, while the posted secondary comparisons are unadjusted recalculations. A multiplicity adjustment, hierarchical testing plan, or other strategy for controlling the interpretation of multiple comparisons is not reported in the registry record.

This matters because the primary p-value addresses the specified primary comparison under its analysis, while repeated testing across outcomes and time points raises the chance of at least one apparently strong finding by chance. The secondary results should not be interpreted as though each arose from a single isolated, prespecified test. The primary endpoint should remain the central inferential result, with secondary outcomes offering supporting descriptive context.

The primary efficacy population is described as intent-to-treat, comprising randomized participants who received at least one dose and had at least one post-baseline efficacy assessment. This definition identifies who was included in the stated primary population, but it is not the same as an all-randomized analysis that includes every randomized participant regardless of post-baseline data. The registry does not report how many randomized participants lacked an assessment, how missing outcome data were handled, or whether sensitivity analyses were performed.

Details of the original analysis plan, including prespecification of all models and handling of protocol deviations, are not reported in the registry record. The record also does not report interim analyses. These absences do not establish that such procedures were or were not used; they limit what can be evaluated from the registry entry. Without those details, interpretation should distinguish the posted primary ANCOVA from the summary-based secondary recalculations and avoid assuming unreported safeguards or analytic decisions.

16. 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 1% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists zero serious adverse events among 95 participants at risk in the dentifrice-plus-rinse group and zero among 96 participants at risk in the dentifrice-alone group. These figures mean that no serious adverse events are recorded for the specified groups and risk populations in this entry. They do not establish that no serious event could occur, or that the groups are equivalent in safety.

Other adverse events are listed for 11 of 95 participants at risk in the dentifrice-plus-rinse group and 7 of 96 at risk in the dentifrice-alone group. These are reported separately from serious adverse events; the registry record does not give event details in the listed summary. Death counts are not reported in the registry record. The available safety counts should be interpreted within the study’s eight-week follow-up and the recorded risk groups, not as a complete assessment of longer-term safety or of every possible event.

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

The posted primary result shows that the average Schiff Sensitivity Score decreased more from baseline to week 8 in the group using mouthwash with dentifrice than in the group using dentifrice alone. The sponsor’s ANCOVA estimated a net mean difference of -1.10, with a 95% confidence interval from -1.28 to -0.92. The reported p-value was < 0.001. These statistics describe the average contrast on the registry’s examiner-rated scale for the primary efficacy population.

The result does not mean that every participant experienced a reduction, or that the size of the group-average difference describes any individual’s response. Group means do not show the distribution of responses or the proportion meeting a responder definition. No responder threshold is reported in the registry record. Nor does statistical evidence against a null difference, by itself, determine whether the magnitude is important to participants.

The study record concerns an eight-week comparison in a single-centre setting, among participants meeting the stated sensitive-teeth criteria. It does not establish persistence beyond the recorded follow-up, effects in different populations or settings, or outcomes that were not measured. Numerical results for the listed visual rating scale outcomes are not reported in the registry record, and further information about missing data and the full analysis plan is not reported.

Safety and efficacy are separate questions. The registry records no serious adverse events in the listed risk groups and gives counts for other adverse events, but those figures do not prove absence of risk or establish comparative safety beyond the observation period. The appropriate interpretation is bounded by the measures, analysis population, follow-up, and information recorded for this trial.

18. Why This Trial Matters Statistically

This trial is statistically informative because it combines a defined continuous primary outcome with a randomized, parallel comparison and a sponsor-reported model-based estimate. The Schiff scale has explicit scoring rules and a direction that makes change interpretable: lower scores indicate less sensitivity, and a reduction from baseline is described as improvement. The registry also reports a confidence interval, allowing the size and precision of the primary contrast to be considered alongside its p-value.

The comparison illustrates why sign conventions matter. The sponsor’s ANCOVA reports a negative net difference, whereas an unadjusted recalculation expressed as dentifrice alone minus dentifrice plus rinse is positive. Both describe the same direction when the order of subtraction is made explicit. Reporting the contrast with its group order avoids mistaking a sign change for a disagreement in results.

The record also illustrates the distinction between adjusted sponsor analysis and summary-statistic recalculation. The latter can check whether the displayed means tell a coherent directional story, but cannot reconstruct an ANCOVA without its full model details. Similarly, consistent directions across posted secondary measures can add descriptive context, while multiple testing and absent multiplicity information prevent treating all those comparisons as equally confirmatory.

Finally, precision and planning are distinct. The primary confidence interval describes uncertainty around an estimated effect, while the planning illustrations show how hypothetical participant counts vary with assumed effect size and power. Those illustrations are not evidence of the trial’s original design rationale or its observed power. Keeping these statistical roles separate supports a more careful reading of the registry findings.

19. 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 information for independently assessing the full analysis. It identifies ANCOVA for the primary comparison but does not report the model covariates or full specification. The primary efficacy population excludes randomized participants without at least one dose and one post-baseline efficacy assessment by its stated definition; counts and characteristics of excluded or missing participants are not reported. The missing-data method and sensitivity analyses are also not reported in the registry record.

The record does not report the trial’s original sample-size justification, full statistical analysis plan, or any interim analyses. The planning illustrations based on the observed effect cannot fill those gaps. A multiplicity strategy is not reported, so secondary comparisons should be read cautiously. Numerical results for the visual rating scale outcomes are not reported in the registry record, despite those outcomes appearing in the secondary-outcome list.

The design description identifies a single centre, an eight-week duration, and examiner blinding, while the registry lists single masking. Further details about masking procedures and their success are not reported. The primary outcome is an examiner-assessed response to an air stimulus; the record does not report participant-level distributions or a threshold for a clinically important score difference. The reported mean therefore cannot convey the range of individual experiences.

The brief summary describes enrollment of 191, while arm summaries for the primary outcome list 95 participants in each arm. The registry record does not explain the relation between these figures, so no reason for their difference should be inferred. Follow-up beyond the stated study period, longer-term effects, and generalizability to other settings are not established by the posted information.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Clinical Study Investigating the Efficacy of a Mouthwash in Providing Long Term Relief From Dentinal Hypersensitivity — NCT02226562.
• Registry record last updated 2018-08-27; status last verified 2018-07.
• Results first posted 2015-08-26.
• 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.

23. Record Summary

The registry describes a completed Phase 2, randomized, single-centre, parallel study comparing a potassium nitrate and sodium fluoride mouthwash plus standard fluoride dentifrice with dentifrice alone. The study period was eight weeks, and the primary outcome was mean change in Schiff Sensitivity Score from baseline to week 8 in the stated intent-to-treat efficacy population.

The sponsor-reported ANCOVA gave a net mean difference of -1.10, with a 95% confidence interval from -1.28 to -0.92 and p < 0.001. The posted arm means were -1.47 and -0.37. Secondary numerical results show a broadly aligned direction, but they are unadjusted recalculations; visual rating scale results are not reported in the registry record.

The entry lists zero serious adverse events in both risk groups and other adverse events in each group. Important details, including the full analysis plan, multiplicity strategy, and missing-data handling, are not reported in the registry record.