This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study in Dentinal Hypersensitivity (DH) Participants to Assess the Efficacy of an Occluding Dentifrice. (NCT02753075), a randomized na study. The primary outcome is Change From Baseline in Schiff Sensitivity Score of Experimental Oral Rinses 1 and 2 Against a Placebo Oral Rinse at Week 8.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02753075 |
| Phase | NA |
| Condition | Dentin Sensitivity |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 240 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
Participants with dentinal hypersensitivity. The primary outcome population was defined as participants who were randomized, received study treatment at least once, and had at least one post-baseline efficacy assessment. The registry record lists a total enrollment of 240.
Intervention
Two experimental oral rinses were assessed as additions to twice-daily brushing with standard fluoride toothpaste. One rinse contained 1.5% weight/weight dipotassium oxalate monohydride and 0 parts per million fluoride; the other contained 2.0% weight/weight dipotassium oxalate monohydride and 45 parts per million fluoride. Each regimen involved brushing for 1 minute, then rinsing with 10 ml of the assigned rinse for 1 minute, twice daily for 8 weeks.
Comparator
The comparator was a placebo oral rinse, used after brushing with fluoride toothpaste on the same twice-daily schedule for 8 weeks. The registry record does not describe the placebo rinse's composition.
Primary question
The study asked whether either experimental rinse changed Schiff Sensitivity Scale scores from baseline to Week 8, compared with placebo. The score was based on the examiner's assessment of response to an evaporative air stimulus. A lower score was defined in the registry record as indicating improvement in sensitivity. Numerical changes and between-group comparisons for this outcome are not reported in the registry record, so the recorded question cannot be answered from the posted results.
3. Trial Design
The registry record describes a randomized, double-masked, parallel-group study with a registered enrollment of 240. Its status is completed. The recorded start date is 2015-09-08 and the primary completion date is 2015-12-01. The phase is listed as NA, and the condition is dentin sensitivity.
Participants were assigned to one of three rinse groups: Experimental Oral Rinse 1, Experimental Oral Rinse 2, or Placebo Oral Rinse. All three regimens included brushing with fluoride toothpaste for 1 minute before rinsing with 10 ml of the assigned rinse for 1 minute. The regimen was to be performed twice daily for 8 weeks. The brief description identifies the experimental rinses by their dipotassium oxalate monohydrate concentrations and fluoride content; the placebo formulation is not reported in the registry record.
The primary outcome was change from baseline in Schiff Sensitivity Score at Week 8, comparing each experimental rinse with placebo. Other recorded outcomes included Schiff scores, tactile thresholds, and visual rating scale scores at Week 4 and Week 8. The registry lists 7 outcome measures and 18 analyses. Those counts indicate that multiple measures or analyses were recorded, but do not describe the statistical procedures used for each analysis.
The study title refers to an occluding dentifrice, while the official title and intervention descriptions refer to experimental oral rinses. The intervention descriptions specify rinsing after brushing with fluoride toothpaste. The registry record does not explain the difference in wording. Allocation concealment procedures, the method used to implement masking, site details, and the planned statistical analysis are 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.
Before assignment: A total of 283 participants were screened, out of which 240 participants were randomized.
Overall Study
| Stage | Experimental Oral Rinse 1 | Experimental Oral Rinse 2 | Placebo Oral Rinse |
|---|---|---|---|
| STARTED | 79 | 80 | 81 |
| COMPLETED | 71 | 77 | 78 |
| NOT COMPLETED | 8 | 3 | 3 |
Reasons for not completing this period:
| Reason | Experimental Oral Rinse 1 | Experimental Oral Rinse 2 | Placebo Oral Rinse |
|---|---|---|---|
| Adverse Event | 2 | 1 | 0 |
| Lost to Follow-up | 2 | 0 | 0 |
| Withdrawal of Consent | 1 | 1 | 3 |
| Physician Decision | 3 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Intent-to-treat (ITT) population included all participants who were randomized, received the study treatment at least once 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.
| Characteristic | Unit | Experimental Oral Rinse 1 | Experimental Oral Rinse 2 | Placebo Oral Rinse | Total |
|---|---|---|---|---|---|
| Participants analysed | 79 | 80 | 81 | 240 | |
| Age, Continuous | Years | 40.5 (SD 9.00) | 40.0 (SD 9.81) | 40.5 (SD 8.71) | 40.3 (SD 9.15) |
| Sex: Female, Male: Female | Participants | 67 | 72 | 70 | 209 |
| Sex: Female, Male: Male | Participants | 12 | 8 | 11 | 31 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Schiff Sensitivity Score of Experimental Oral Rinses 1 and 2 Against a Placebo Oral Rinse at Week 8, measured over Baseline, Week 8.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was change from baseline in Schiff Sensitivity Score at Week 8. The examiner assessed the participant's response to an evaporative air stimulus for each of two selected teeth. The scale has four possible scores: 0 indicates no response to air stimulation; 1 indicates a response without a request to stop the stimulus; 2 indicates a response with a request to stop or movement away from the stimulus; and 3 indicates a response in which the stimulus is considered painful and the participant requests that it stop.
The registry record states that a reduction in the score indicates improvement in sensitivity. Measuring change from baseline describes how scores differ over the assessment period, while comparing the changes between groups is intended to distinguish changes in the experimental-rinse groups from changes in the placebo group. The record identifies the scale and assessment time, but does not report the group-level changes or comparisons.
As a general statistical point, a continuous score can be summarized by its mean and standard deviation. The mean describes the average score or change in a group; the standard deviation describes how spread out individual values are around that average. Neither summary alone shows the uncertainty in a comparison between groups. Numerical endpoint estimates and their uncertainty are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary comparison: change from baseline to Week 8 in Schiff Sensitivity Score for each experimental rinse versus placebo. It also explains how to interpret the direction of the scale: a reduction in score indicates improvement in sensitivity. However, the numerical primary outcome results are not reported in the registry record. There are no posted group means, standard deviations, between-group estimates, confidence intervals, or p-values for this comparison in the registry entries. Consequently, the direction, size, and precision of any difference cannot be described.
The registry lists 7 outcome measures and 18 analyses. Secondary outcomes include Schiff scores, tactile thresholds measured in grams, and visual rating scale scores at Week 4 or Week 8. Listing outcomes does not establish that results were statistically significant, nor does it reveal how large any changes were. Numerical results for these outcomes are also not reported in the registry record.
The record's primary-outcome note indicates that the outcome was not reduced to one comparison because it had several categories or time points. This matters for interpretation: a single headline estimate cannot be reconstructed from the outcome description alone. The record does not specify which outcome categories or time points were included in each analysis, or how comparisons across the outcomes were handled.
Precision cannot be assessed without estimates and uncertainty intervals. In general, a confidence interval describes a range of values compatible with the data and the assumptions of the analysis; a narrower interval indicates greater precision than a wider one. No confidence interval for the primary comparison is reported in the registry record. The number of participants enrolled does not by itself establish the precision of the outcome estimate, because the analysis population, variability, missing observations, and model also matter.
The registry record reports adverse-event figures separately from the efficacy outcomes. Serious adverse event figures are 0 for each of the three groups, with 79, 80, and 81 participants respectively listed at risk. Other adverse event figures are 10, 8, and 2 for those groups. These counts are descriptive; they do not supply an efficacy estimate and should not be substituted for one. The record does not provide details about event types in the information available for this analysis.
Overall, the registry record establishes what the trial intended to compare and how the primary measure was defined, but does not include the numerical efficacy results needed to characterize the observed treatment differences. Any conclusion about the size or precision of the Week 8 comparison would go beyond the posted results.
9. Statistical Methods Explained
What does change from baseline represent?
The primary endpoint is a change score: it compares a participant's score at Week 8 with that participant's baseline score. This approach focuses on how the measured response changed over the study period rather than only on the Week 8 score. The study's stated interpretation is that a lower Schiff Sensitivity Score reflects improvement. A treatment comparison would then assess the difference in average change between each experimental-rinse group and the placebo group. The registry record does not report the numerical changes or the results of those comparisons.
As a general statistical explanation, a mean change summarizes the average within-participant change in a group. A standard deviation summarizes how much those changes vary among participants. A between-group estimate expresses the contrast between groups, while its confidence interval describes uncertainty around that estimate under the assumptions of the analysis. A p-value, if reported, would relate the observed data to a specified null hypothesis and statistical model; it would not measure the size or clinical importance of a difference. The record does not report a confidence interval or p-value for the primary outcome.
What does the outcome scale measure?
The Schiff scale is an ordered score based on the examiner's assessment of the response to an air stimulus. Its categories run from no response, through a response that does not lead to a request to stop, to responses that lead to stopping the stimulus, including a response described as painful. Although the registry identifies the primary measure as a mean and gives a standard deviation, the scale's categories have an ordered meaning. The statistical model used to analyze the score is not reported in the registry record. It is therefore not possible to tell whether the analysis treated the score as a continuous measure or used another approach.
As a general point, treating an ordered score as continuous can make a mean difference easy to describe, but the interpretation depends on the scoring scale and the analysis assumptions. A model that respects the ordered categories may answer a different statistical question. Which approach is most appropriate depends on the study's analysis plan and data; the registry record does not identify the approach used.
Why does variability matter?
In general, outcome variability affects how precisely a group mean or between-group contrast can be estimated. Greater variability tends to make an estimate less precise when other aspects of the design are comparable. The standard deviations are identified as the dispersion measure for the primary outcome, but their numerical values are not reported in the registry record. Neither variability nor precision can therefore be assessed from the outcome description alone.
Over-dispersion is a general concern when observed variability exceeds what an assumed statistical model allows. If an analysis ignores over-dispersion, its uncertainty estimates may be too small and its tests may be misleading. The registry record does not identify the model, its assumptions, or whether over-dispersion was assessed. This is a general consideration, not a statement that over-dispersion occurred in this trial.
What is known about analysis populations?
The primary outcome population is defined as participants who were randomized, received study treatment at least once, and had at least one post-baseline efficacy assessment. This definition specifies a group that excludes randomized participants without any post-baseline efficacy assessment and those who never received treatment. Although the record labels this population ITT, the listed eligibility conditions should be read as the registry's operational definition rather than assumed to include every randomized participant regardless of subsequent participation.
The registry record does not report the number analyzed in each group for the primary outcome, the number missing at Week 8, or how missing observations were handled. It also does not describe whether any sensitivity analyses were used to examine the effect of missing data. Without that information, readers cannot assess whether the primary analysis retained all participants meeting the stated definition or how its results might depend on missing observations.
What can planning illustrations tell readers?
As a general explanation, a sample-size calculation can estimate how many participants would be needed to detect a specified effect under stated assumptions. The registry-based planning assumptions described for this study use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is expressed as a stated fraction of the observed effect. These are planning assumptions, not a description of the trial's observed results. The record does not report the resulting participant counts in the information, and the primary observed effect is not reported. Such calculations therefore cannot establish what the trial found or how likely the trial was to detect its actual effect. Planning estimates are not observed power.
The protocol's original sample-size justification, its assumed effect, and any planned interim analyses are not reported in the registry record. The planning assumptions should not be treated as evidence that they were the assumptions used to design or conduct the trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 7 outcome measures and 18 analyses, including multiple outcomes and assessments at Week 4 and Week 8. When a study evaluates several outcomes, time points, or group comparisons, the chance of obtaining at least one apparently unusual result can increase if each test is considered separately. As a general statistical principle, methods such as a prespecified hierarchy or adjustment for multiple comparisons can address that issue, but the suitable approach depends on the study's aims and analysis plan.
The registry record does not report whether the analyses were prespecified, whether a primary comparison was prioritized in the inferential plan, or whether any adjustment for multiple testing was used. The primary outcome note says that the outcome has several categories or time points and was not reduced to one comparison. The record does not explain how those analyses relate to one another. The list of 18 analyses alone cannot show whether multiplicity was controlled.
The primary analysis population requires randomization, receipt of study treatment at least once, and at least one post-baseline efficacy assessment. The record does not report group-specific counts for this population, missing outcome counts, reasons for missingness, or the method used to handle missing data. It also does not state whether analyses included all participants with available observations, used imputation, or applied another approach. These details are important because missingness can affect the estimated changes and their uncertainty, particularly if the likelihood of missing data differs between groups or relates to outcomes. No such pattern can be inferred from the information reported.
The registry record's analysis-population definition and the absence of reported missing-data methods limit assessment of how representative the analyzed participants were of everyone randomized. The extent and direction of any resulting bias cannot be determined from the record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Experimental Oral Rinse 1 | 0 | 79 | 0.0% |
| Experimental Oral Rinse 2 | 0 | 80 | 0.0% |
| Placebo Oral Rinse | 0 | 81 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Experimental Oral Rinse 1 | 10 of 79 |
| Experimental Oral Rinse 2 | 8 of 80 |
| Placebo Oral Rinse | 2 of 81 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Experimental Oral Rinse 1 | Experimental Oral Rinse 2 | Placebo Oral Rinse |
|---|---|---|---|---|
| ORAL DISCOMFORT | Gastrointestinal disorders | 4 of 79 | 2 of 80 | 0 of 81 |
| DRY MOUTH | Gastrointestinal disorders | 3 of 79 | 2 of 80 | 0 of 81 |
| GLOSSODYNIA | Gastrointestinal disorders | 1 of 79 | 3 of 80 | 0 of 81 |
| GINGIVAL PAIN | Gastrointestinal disorders | 2 of 79 | 1 of 80 | 0 of 81 |
| TRAUMATIC ULCER | Injury, poisoning and procedural complications | 2 of 79 | 0 of 80 | 1 of 81 |
| HYPOAESTHESIA ORAL | Gastrointestinal disorders | 2 of 79 | 0 of 80 | 0 of 81 |
| LIP EXFOLIATION | Gastrointestinal disorders | 1 of 79 | 0 of 80 | 0 of 81 |
| LIP SWELLING | Gastrointestinal disorders | 1 of 79 | 0 of 80 | 0 of 81 |
| ORAL MUCOSAL EXFOLIATION | Gastrointestinal disorders | 0 of 79 | 0 of 80 | 1 of 81 |
| PARAESTHESIA ORAL | Gastrointestinal disorders | 0 of 79 | 1 of 80 | 0 of 81 |
The registry lists serious adverse event figures of 0 for Experimental Oral Rinse 1, 0 for Experimental Oral Rinse 2, and 0 for Placebo Oral Rinse. The corresponding numbers listed at risk are 79, 80, and 81. These are the posted serious adverse event figures; they should not be interpreted as proof that no safety events of any kind occurred.
For other adverse events, the figures are 10, 8, and 2, respectively, among the same group-specific numbers at risk. The record does not give the event terms in the information available for this analysis; the list of top serious terms is empty. Counts describe what was recorded but do not indicate event severity beyond the separate serious-event classification, timing, duration, or causal relationship to treatment. The record also does not report deaths as a numerical value; the death entries are null, so deaths are not reported in the registry record rather than documented as zero.
As a general statistical point, safety counts are interpreted in light of the number exposed, the duration of follow-up, definitions of events, and how events were collected. The registry record identifies an 8-week regimen but does not provide detailed exposure or event-collection information. These figures are descriptive and do not establish that one regimen is safer than another.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the trial compared two experimental oral rinses with a placebo rinse, each used after brushing with fluoride toothpaste, and that the main efficacy question concerned change in Schiff Sensitivity Score at Week 8. It also defines the score's categories and states that a reduction indicates improvement. These details clarify the intended comparison and the meaning of the endpoint.
The record does not report numerical primary outcome results. It therefore does not establish the average change in any group, the difference between either experimental rinse and placebo, the uncertainty around those differences, or whether any comparison met a statistical threshold. The same caution applies to the listed secondary outcomes: naming an outcome and an assessment time does not reveal its result.
As a general statistical distinction, statistical significance and effect size address different questions. A test result concerns compatibility with a specified statistical model and null hypothesis; the estimated effect describes the magnitude and direction of a difference. A confidence interval helps describe precision. None of those primary comparison results is reported in the registry record, so neither statistical significance nor the size or precision of the effect can be assessed.
The completed status and registered enrollment of 240 do not fill this gap. Enrollment describes the trial's registered size, not the number included in each outcome analysis. The primary analysis population has additional eligibility conditions, and its group-specific sizes are not reported. Nor does enrollment alone reveal the amount of missing data or the variability in scores.
The adverse-event figures are separate descriptive information. They should not be used as a proxy for efficacy, and the posted counts do not by themselves support a comparative safety conclusion. Overall, the available registry information describes the design, treatment regimens, outcomes, and certain adverse-event counts, but does not provide the numerical efficacy evidence needed to determine the observed Week 8 comparison.
13. Why This Trial Matters Statistically
This trial illustrates why a clearly stated clinical question and a reported numerical result are both needed for statistical interpretation. The registry record identifies the population, the three rinse groups, the assessment schedule, and a primary measure with an explicit direction of interpretation. A reader can understand what the researchers intended to compare without confusing the Schiff score with the tactile threshold or visual rating scale outcomes.
At the same time, a detailed outcome definition is not a substitute for results. The registry lists 7 outcome measures and 18 analyses, but numerical primary estimates and their uncertainty are not reported in the registry record. Without those, readers cannot assess the magnitude, direction, or precision of the central comparison. This is an important distinction between a record of what a study set out to assess and a report of what its data showed.
The trial also highlights the value of transparent reporting about analysis populations, missing observations, and multiplicity. The registry gives an operational definition for the primary outcome population, but does not report group-specific analysis counts or how missing data were addressed. It identifies multiple outcomes and analyses without describing how the analyses were prioritized or whether multiplicity was handled. These omissions constrain the statistical conclusions that can be drawn even when the design and measurement are described.
Finally, adverse-event counts and efficacy outcomes answer different questions. Reporting both is useful, but each requires its own context and analysis. Here the serious and other adverse-event figures are available, whereas the primary efficacy comparison is not. Statistical interpretation should reflect that asymmetry rather than treating one kind of information as evidence for the other.
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 efficacy is that numerical primary outcome results are not reported in the registry record. Group means, standard deviations, changes from baseline, between-group estimates, confidence intervals, and p-values are not available in the information used for this analysis. The direction and magnitude of the primary comparison therefore cannot be described.
The registry record also does not report the statistical model or test used for the Schiff score, the handling of its ordered categories, or the assumptions checked in the analysis. Although it identifies mean and standard deviation as the outcome summary and dispersion measure, it does not give their values. Details of covariate adjustment, if any, are not reported in the registry record.
The record lists several outcomes and analyses but does not report whether comparisons were prespecified, how multiplicity was addressed, or which analysis was considered controlling. The primary outcome note indicates multiple categories or time points, without explaining their role in the analyses. This makes it difficult to evaluate how the primary comparison was selected and how secondary findings, if any, should be interpreted.
Information about missing data is also limited. The primary population definition requires a post-baseline assessment, but group-specific analysis sizes, the extent and reasons for missing outcome data, and the approach to missingness are not reported in the registry record. The protocol's sample-size justification and any interim analyses are not reported. The record also does not explain the difference between the study title's reference to a dentifrice and the official title's reference to oral rinses. These reporting gaps restrict assessment of both the analysis and the study's results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study in Dentinal Hypersensitivity (DH) Participants to Assess the Efficacy of an Occluding Dentifrice. — NCT02753075.
- Registry record last updated 2018-08-27; status last verified 2018-07.
- Results first posted 2017-03-06.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT02753075 is a completed, randomized, double-masked, parallel study of dentinal hypersensitivity, with a registered enrollment of 240. It compared two experimental oral rinses with a placebo rinse, used after brushing with fluoride toothpaste twice daily for 8 weeks. The primary outcome was change from baseline to Week 8 in Schiff Sensitivity Score, for which the registry states that a lower score indicates improvement.
The registry lists 7 outcome measures and 18 analyses and defines the primary outcome population as randomized participants who received treatment at least once and had at least one post-baseline efficacy assessment. Numerical results for the primary efficacy comparison, its precision, and the analysis methods are not reported in the registry record. Serious adverse event figures are 0 in each group; other adverse event figures are 10, 8, and 2. The registry does not report numerical death results.