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 To Investigate the Efficacy of an Occluding Dentifrice in Dentinal Hypersensitivity (DH) (NCT02923895), a randomized phase 4 study. The primary outcome is Change From Baseline in Schiff Sensitivity Score on Day 3.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02923895 |
| Phase | Phase 4 |
| Condition | Dentin Sensitivity |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 197 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
Participants with dentinal hypersensitivity were enrolled at a single centre. The registry record reports enrollment of 197. The primary outcome analysis population was defined as participants who were randomized, received study treatment at least once, and had at least one post-baseline assessment.
Intervention
The test treatment was a stannous fluoride-containing dentifrice. Participants were instructed to brush each qualifying test tooth for 30 seconds, then brush the whole mouth for at least 1 timed minute, twice daily.
Comparator
The control was a standard fluoride dentifrice, described in the interventions as sodium monofluorophosphate. Participants were instructed to brush the whole mouth for at least 1 minute, twice daily.
Primary question
The primary question was whether the mean change from baseline in Schiff Sensitivity Score on Day 3 differed between the test and control dentifrices. A lower score represented reduced sensitivity. The registry record does not report the numerical between-group comparison.
The endpoint was assessed by an examiner using an evaporative air stimulus on the test teeth. The score reflects the participant’s response, ranging from no response to a response described as painful with a request to stop the stimulus. The participant-level change was calculated from the average score for the test teeth.
This describes the question the study was designed to address, not a conclusion about the relative effects of the dentifrices. The registry record identifies a randomized study and the endpoint, but the numerical primary outcome result, its uncertainty, and a statistical test result are not reported in the registry record. Without those results, the size and precision of any observed difference cannot be assessed from the record.
3. Trial Design
The registry record identifies this as a Phase 4, randomized, single-masked, parallel-group study. The brief summary describes a single-centre comparison of an experimental stannous fluoride-containing dentifrice with a standard fluoride dentifrice, focused on short-term relief of dentinal hypersensitivity. Enrollment was 197, and the study status is completed. The recorded study start was 2016-10-11, and the primary completion date was 2016-12-16.
In a parallel-group design, participants are assigned to one treatment group and outcomes are compared across groups. Random allocation is intended, in general, to make treatment groups comparable at the start with respect to measured and unmeasured characteristics, on average. It does not guarantee identical groups in a particular trial. The registry record does not describe the sequence-generation method or allocation concealment, so those details are not reported in the registry record.
The record says masking was single, but does not identify which people were masked. The identity of the masked party, and the procedures used to maintain masking, are not reported in the registry record. These details matter because knowledge of assignment can affect care, outcome assessment, or participant reporting; the extent to which that could apply depends on who was masked and on how outcomes were collected.
The test and control instructions differed: the test group brushed qualifying test teeth before whole-mouth brushing, while the control group brushed the whole mouth. Both sets of instructions specified twice-daily use. The registry record does not give the duration of treatment beyond the short-term context, details of adherence assessment, or whether any additional care was permitted. Those design details are not reported in the registry record.
The record lists four outcome measures, including the primary Day 3 Schiff Sensitivity Score change and secondary measures involving tactile threshold and a Schiff score after a single use. The registry record does not describe a sample-size justification, interim analyses, or the detailed statistical plan. Those features should not be inferred from the randomized design or the enrollment count.
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 197 participants were screened and enrolled in the study, out of which 192 participants were randomized to the study treatments. Five participants were not randomized: 1 participant was screening failure, and 4 participants withdrew their consent.
Overall Study
| Stage | Test Dentifrice | Control Dentifrice |
|---|---|---|
| STARTED | 97 | 95 |
| COMPLETED | 97 | 95 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Analysis for this outcome was performed on Intent-to-treat (ITT) population, defined as all participants who were randomized, received the study treatment at least once and provided at least one post-baseline (post treatment) assessment.
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 | Test Dentifrice | Control Dentifrice | Total |
|---|---|---|---|---|
| Participants analysed | 97 | 95 | 192 | |
| Age, Continuous | Years | 46.8 (SD 12.95) | 46.9 (SD 10.53) | 46.9 (SD 11.79) |
| Sex: Female, Male: Female | Participants | 68 | 72 | 140 |
| Sex: Female, Male: Male | Participants | 29 | 23 | 52 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 16 | 12 | 28 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 18 | 31 | 49 |
| Race (NIH/OMB): White | Participants | 62 | 51 | 113 |
| Race (NIH/OMB): More than one race | Participants | 1 | 1 | 2 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Schiff Sensitivity Score on Day 3, measured over Baseline and Day 3.
| 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 on Day 3. The examiner assessed response to an evaporative air stimulus for each test tooth. The scale ranged from 0, meaning no response to air stimulation, through 1, a response without requesting that the stimulus stop, and 2, a response accompanied by a request to stop or movement away from the stimulus, to 3, a response described as painful with a request to stop.
The score was calculated as the average of the individual test-tooth scores. The participant-level change was the mean change from baseline across the test teeth. A reduction in score indicated improvement in sensitivity according to the registry description. The endpoint is therefore a continuous participant-level change measure derived from an ordered response scale; the registry treats it as a mean with standard deviation.
General: a baseline-to-follow-up change score can describe how a measure shifted during the study. A comparison between randomized groups is needed to distinguish the relative change associated with assignment to each treatment from changes that may occur over time in both groups. The registry record does not provide the numerical group means, standard deviations, treatment contrast, confidence interval, or p-value for this primary endpoint. Its observed magnitude and precision are therefore not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome is identified as a mean change in Schiff Sensitivity Score from baseline to Day 3. The registry record explains how the score was collected and how a reduction was interpreted, but it does not report numerical group results or a between-group estimate. Consequently, the record does not establish the direction or size of the observed treatment contrast, nor does it show how precisely that contrast was estimated.
A treatment comparison is most informative when accompanied by an estimate of the difference between groups and an interval describing uncertainty. A confidence interval, in general, gives a range of values compatible with the data and the analysis assumptions. Its width helps readers judge precision; it is not a guarantee that the true value lies within that particular interval. No confidence interval for the primary comparison is reported in the registry record. No primary comparison p-value is reported either.
The record lists one analysis, but the numerical result of that analysis is not reported in the registry record. The analysis population is described as participants who were randomized, received treatment at least once, and provided at least one post-baseline assessment. That definition is important: it does not include every randomized participant automatically, because receipt of treatment and a post-baseline assessment are also required. The count analyzed in each group is not reported in the registry record.
The listed primary outcome concerns Day 3, while the secondary outcomes include change in tactile threshold on Day 3 and changes in tactile threshold and Schiff score after a single use. The record also indicates that the primary outcome has several categories or time points and is not reduced to one comparison. This means the reported endpoint structure is broader than a single summary contrast; without the category-specific results and analysis details, the full pattern cannot be assessed.
There is no basis in the registry record for declaring that either dentifrice performed better, or that the treatments were equivalent. A missing numerical result is not evidence of no difference. Likewise, the recorded trial completion status does not supply an efficacy finding. Any conclusion about the observed effect would require results not reported in the registry record, including the group-level outcome summaries and the prespecified comparison.
General: statistical significance and clinical importance are different questions. A statistical test addresses how compatible observed data are with a specified null model, given its assumptions. Clinical importance concerns whether the magnitude of an effect matters in context. Neither question can be evaluated from the primary endpoint description alone. The registry record does not report a clinical threshold for interpreting the size of a change.
9. Statistical Methods Explained
What does a randomized parallel-group design contribute?
Random allocation assigns participants to treatment groups using a chance-based process. In general, this helps prevent systematic selection from determining which treatment a participant receives. It supports a fair comparison by making baseline differences less predictable, but it does not ensure that every characteristic will be balanced in the realized groups. The registry record identifies the study as randomized and parallel-group; the sequence-generation and concealment procedures are not reported in the registry record.
In a parallel-group study, each participant is assigned to one treatment group, and the outcome is compared across groups. This differs from a crossover design, where a participant receives more than one treatment in sequence. The registry record does not describe crossover periods; its stated model is parallel. The record also identifies single masking, but who was masked and how masking was maintained are not reported in the registry record.
How should the primary outcome be understood?
The primary measure is a mean of participant-level changes in Schiff Sensitivity Score, evaluated at baseline and Day 3. The scale is based on response to an air stimulus, with categories from 0 to 3. Although the categories are ordered, the registry describes the outcome as a mean with standard deviation. The participant-level measure averages responses for the test teeth, and the change score compares that measure with baseline.
General: a mean describes the central value of a numerical measure, while a standard deviation describes how spread out individual measurements are around that mean. A standard deviation is not the same as the uncertainty in the estimated mean. The latter depends on the amount of information and the analysis, and is commonly conveyed using a confidence interval. No group means, standard deviations, or confidence interval for the primary comparison are reported in the registry record.
What does a between-group estimate tell readers?
General: an unadjusted comparison can be expressed as a difference between the groups’ average outcome changes. The estimate describes the observed contrast, while a confidence interval conveys its statistical precision under the analysis assumptions. A p-value summarizes compatibility with a null hypothesis; it does not measure effect size, the probability that the null hypothesis is true, or clinical importance.
The registry record does not report the numerical primary contrast or its statistical uncertainty. It therefore does not support interpretation of the contrast’s direction, magnitude, or precision. The record lists one analysis, but that count does not substitute for the estimate and uncertainty needed to interpret the result.
How do planning illustrations differ from observed power?
General: a sample-size calculation for a future study depends on assumptions about the effect to detect, variability, significance level, allocation, and the statistical model. A planning illustration asks what sample size would be needed under selected assumptions. It is not the number of participants actually analyzed and is not an observed trial result.
The registry record describes planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustrations use a stated fraction of the observed effect as the effect to detect. For non-time-to-event outcomes, such illustrations are expressed as participants per arm for 80% power or for 90% power; time-to-event illustrations would use a total event count. These are planning assumptions, not evidence of the trial’s achieved power. The numerical illustrations are not reported in the registry record.
General: retrospective power calculations based on an observed effect do not provide an independent measure of certainty. The effect estimate and its confidence interval describe the data more directly. Any planning number based on an observed effect can be particularly sensitive to uncertainty in that effect. It should not be interpreted as a guarantee that a future study will detect the same effect.
What can be concluded about model assumptions?
The primary outcome is described as continuous and summarized by a mean and standard deviation. General: methods for comparing means make assumptions about how outcome variation is modeled and how observations contribute to the estimate. The suitability of a method depends on the outcome distribution, study design, missingness, and any adjustments specified in the analysis plan. The registry record does not report the statistical test or model, any covariate adjustments, diagnostics, or sensitivity analyses. Those methods are not reported in the registry record and should not be inferred from the outcome’s summary format.
General: over-dispersion matters when the observed variability is greater than a model assumes. If a model understates variability, its uncertainty estimates can be too narrow. This is a general concern in statistical modeling, not a finding about this trial. The registry record does not report a model or evidence of over-dispersion for the primary endpoint.
For outcomes based on ordered categories, treating scores numerically and comparing means is one possible summary approach, but the interpretation depends on the measurement and analysis choices. The registry record specifies a mean-based primary outcome; it does not report whether other analytical approaches were considered. No model-specific conclusion can be drawn from the endpoint description alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists four outcome measures: the primary Day 3 change in Schiff Sensitivity Score and secondary outcomes involving tactile threshold on Day 3, Schiff Sensitivity Score after a single use, and tactile threshold after a single use. It also indicates that the primary outcome has several categories or time points and is not reduced to one comparison. The detailed set of comparisons and category-specific numerical results are not reported in the registry record.
General: when many outcomes, time points, or subgroup comparisons are tested, the chance of finding at least one apparently unusual result can increase. A prespecified hierarchy, adjustment, or other multiplicity strategy can help readers understand how a family of tests was handled. The registry record does not report a multiplicity adjustment or decision hierarchy, so whether and how multiplicity was addressed is not reported in the registry record.
The primary outcome population was defined as all randomized participants who received study treatment at least once and provided at least one post-baseline assessment. This is an analysis population with treatment-exposure and follow-up requirements, rather than all randomized participants without qualification. The number analyzed in each group and the reasons participants may have been excluded are not reported in the registry record.
General: missing outcome data can affect interpretation, particularly if the likelihood of missingness is related to treatment or outcome. Analyses may use different assumptions or methods to address missing observations, and sensitivity analyses can assess whether conclusions depend on those assumptions. The registry record does not describe missing-data amounts, reasons for missingness, imputation, or sensitivity analyses. These details are not reported in the registry record.
The registry record’s one-analysis count does not establish that there was only one statistical question or one outcome comparison. A complete assessment would require the analysis plan, the reported outcome data, and details of any multiplicity and missing-data procedures. Those details are not reported in the registry 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 |
|---|---|---|---|
| Test Dentifrice | 0 | 97 | 0.0% |
| Control Dentifrice | 0 | 95 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Test Dentifrice | 0 of 97 |
| Control Dentifrice | 0 of 95 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Test Dentifrice | 1 of 97 |
| Control Dentifrice | 0 of 95 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Test Dentifrice | Control Dentifrice |
|---|---|---|---|
| Headache | Nervous system disorders | 1 of 97 | 0 of 95 |
The registry record reports serious adverse events for the test dentifrice group as 0 among 97 participants at risk, and for the control dentifrice group as 0 among 95 participants at risk. Deaths were 0 in both groups. For the other adverse-event category, the record reports 1 among 97 participants at risk in the test group and 0 among 95 participants at risk in the control group. No serious adverse-event terms are listed.
These are event counts within the stated groups, not evidence that no adverse events of any kind occurred. The record distinguishes serious events from other adverse events; the single event in the other category is not described further in the registry record reported. Its nature, timing, severity, and relationship to treatment are not reported in the registry record.
General: a zero count in a study does not establish that an event cannot occur. Safety counts should be interpreted in light of the number of people observed, the duration of observation, event definitions, and completeness of reporting. The registry record does not provide the follow-up duration for safety assessment or further detail on ascertainment. These limitations mean the figures describe what was recorded for this study, not the full range of possible risks.
The counts do not establish a comparative safety difference. The registry record reports no serious events in either group, but does not provide a statistical comparison or uncertainty interval for safety outcomes. These figures should be read descriptively rather than as proof of equal safety.
12. What the Result Does, and Does Not, Mean
The registry record describes a randomized comparison of a stannous fluoride-containing dentifrice with a standard fluoride dentifrice in participants with dentinal hypersensitivity. It identifies a short-term primary endpoint based on change in Schiff Sensitivity Score at Day 3 and explains how that score was derived. It also describes the analysis population and reports selected adverse-event counts.
What the record does not report is the numerical primary outcome comparison. Group-level means and standard deviations, the estimated treatment contrast, its confidence interval, and a p-value are not reported in the registry record. As a result, readers cannot determine the direction, magnitude, or precision of the observed primary outcome difference from the registry record. The absence of those numerical results cannot be interpreted as evidence that there was no difference.
The study’s completed status and enrollment count are not efficacy results. Nor does the presence of a primary endpoint establish that its result favored either group. The secondary outcomes are named, but their numerical results are not reported in the registry record. Accordingly, the record does not permit a full evaluation of consistency across endpoints or time points.
General: a treatment estimate and its uncertainty answer statistical questions about the observed data, while clinical interpretation also depends on the relevance of the outcome and the size of a meaningful change. The registry record does not report a threshold for a clinically important change in Schiff Sensitivity Score. Even with a numerical estimate, that additional context would be needed to judge its practical significance.
The safety information is limited to reported counts: no serious adverse events or deaths are recorded in either group, and the other adverse-event category contains one event in the test group and none in the control group. These counts are descriptive and do not by themselves establish that risks are absent or identical. The overall interpretation is therefore constrained by the missing numerical efficacy results and limited detail on analysis and follow-up.
13. Why This Trial Matters Statistically
This trial is statistically notable as a randomized, parallel-group comparison using a short-term, examiner-assessed sensitivity outcome. Its endpoint combines responses from the test teeth into a participant-level mean change, making clear that the reported unit of analysis is the participant rather than each individual tooth response. That distinction matters because observations from the same participant are related and should not automatically be treated as independent.
The trial also illustrates why an outcome definition and a result are different kinds of information. The registry record carefully describes the Schiff scale and specifies that lower scores indicate reduced sensitivity, but does not report the numerical comparison between groups. A detailed endpoint definition helps explain what an estimate would mean; it cannot replace the estimate, its uncertainty, or the analysis method.
The analysis population definition is another important statistical feature. Participants had to be randomized, receive study treatment at least once, and provide a post-baseline assessment. This qualification affects which participants contribute to the primary outcome analysis. Because the analyzed group counts and missing-data handling are not reported in the registry record, readers cannot assess the consequences of those criteria.
More broadly, the record shows why clinical trial interpretation depends on transparent reporting of estimates, uncertainty, analysis decisions, and outcome timing. The listed adverse-event counts offer descriptive safety information, but not a comprehensive risk comparison. The stated planning assumptions likewise describe hypothetical sample-size illustrations, not observed power or the precision of the trial result. The registry record supplies design and endpoint context, while leaving essential numerical efficacy and analysis details not reported.
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 statistical interpretation is that the registry record does not report the numerical result for the primary endpoint. Without group summaries and a between-group estimate, there is no basis for assessing the observed effect’s direction, size, or precision. The record also does not report a confidence interval or p-value for the primary comparison.
The analysis population is defined, but the number analyzed in each group, exclusions from analysis, and reasons for missing assessments are not reported in the registry record. Missing-data methods and sensitivity analyses are also not reported. These omissions prevent assessment of how complete follow-up was or how analysis choices may have influenced the estimate.
Although the study is identified as randomized and single-masked, the randomization procedure, allocation concealment, and identity of the masked party are not reported in the registry record. The statistical test or model, any covariate adjustment, and the approach to multiple outcomes or time points are also not reported. The registry indicates that the primary outcome has several categories or time points and is not reduced to one comparison, but does not provide the detailed results needed to interpret that structure.
The record describes a single-centre study and short-term outcomes, including Day 3 and after-single-use assessments. It does not report longer-term outcome results in the registry record. Adherence information, treatment duration details, and safety follow-up duration are not reported in the registry record. These limits constrain interpretation of durability and the broader applicability of the findings.
The adverse-event information is restricted to the recorded counts and does not describe the single event in the other category. The absence of reported serious events does not establish that serious events are impossible. Finally, the planning assumptions do not substitute for a reported sample-size rationale or an observed treatment estimate; the sample-size justification for the trial is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: To Investigate the Efficacy of an Occluding Dentifrice in Dentinal Hypersensitivity (DH) — NCT02923895.
- Registry record last updated 2018-10-29; status last verified 2018-06.
- Results first posted 2018-10-29.
- 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.
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18. Record Summary
The registry record describes a completed Phase 4, randomized, single-masked, parallel-group, single-centre study comparing a stannous fluoride-containing test dentifrice with a standard fluoride control for dentinal hypersensitivity. Enrollment was 197. The primary endpoint was change from baseline in mean Schiff Sensitivity Score on Day 3; lower scores indicated reduced sensitivity.
The primary analysis population required randomization, at least one treatment exposure, and at least one post-baseline assessment. The numerical primary comparison and its uncertainty are not reported in the registry record. The record lists three secondary outcomes, alongside the primary outcome, and reports no serious adverse events or deaths in either group. One other adverse event was recorded in the test group and none in the control group.
Important statistical details, including the model, multiplicity handling, missing-data methods, and group analysis counts, are not reported in the registry record. Planning illustrations are described as assumption-based and should not be interpreted as observed power.