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 An Evaluation of Protective Effects of OpalSeal™ Against Early Dental Decay in Orthodontic Patients (NCT03722264), a randomized na study. The primary outcome is Loss of Mineral Density in the Enamel.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03722264 |
| Phase | NA |
| Condition | Cavities of Teeth |
| Allocation | Randomized |
| Design model | Single Group |
| Masking | Double |
| Enrollment | 12 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Virginia Commonwealth University |
| Results posted | Yes |
2. Clinical Question
Population
Orthodontic patients receiving braces were the study population. The registry records enrollment of 12 participants. For the primary endpoint, 9 teeth in each group were available for analysis; the record does not explain how those teeth were distributed across participants.
Intervention
OpalSeal, a fluoride-releasing primer, was applied during orthodontic bonding. The description specifies application to buccal surfaces of teeth scheduled for extraction, or to proximal surfaces following interproximal reduction (IPR), according to the stated procedure.
Comparator
Transbond XT was the conventional primer comparator. The described application was to the other side of the mouth for buccal surfaces of teeth scheduled for extraction, or to proximal surfaces following IPR. The side receiving OpalSeal was determined randomly for each participant.
Primary question
The study asked whether enamel mineral-density loss, measured as lesion depth in microns, differed between teeth treated with OpalSeal and teeth treated with Transbond XT. Teeth were assessed by microCT from initial bonding to extraction, with a maximum timeframe of 90 days. The registry record does not report a statistical test or an inferential estimate for this comparison.
3. Trial Design
This was a completed pilot study sponsored by Virginia Commonwealth University. The registry lists randomized allocation and double masking, and classifies the study model as single-group. It also reports results for OpalSeal and Transbond XT, with each described as an arm. The record does not explain how the single-group classification relates to the two reported treatment groups.
The intervention descriptions indicate a within-mouth comparison: for teeth on buccal surfaces, OpalSeal was applied on one side and Transbond XT on the other, with the side receiving OpalSeal determined randomly for each participant. The descriptions also refer to application on proximal surfaces following IPR. Further details on how participants or teeth entered each application pathway are not reported in the registry record.
The study enrolled 12 participants. The primary endpoint analysis included 9 teeth in each group. The record does not state whether all enrolled participants contributed teeth to both groups, how many teeth each participant contributed, or whether the statistical analysis accounted for teeth clustered within participants. The protocol’s allocation unit and the roles of the people masked are not reported in the registry record.
The study started on 2017-11-16, reached primary completion on 2019-04-12, and is listed as completed. Its phase is recorded as NA. These registry classifications describe the registered study; they do not supply additional detail about its procedures or analysis. A sample-size justification and a detailed statistical plan 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.
Overall Study
| Stage | Bilateral Treatment With OpalSeal and Transbond XT |
|---|---|
| STARTED | 12 |
| COMPLETED | 9 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Bilateral Treatment With OpalSeal and Transbond XT |
|---|---|
| Physician Decision | 3 |
Analysis population for the primary outcome, as defined in the registry: 9 teeth in each group were available for analysis
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.
Population: Although age was used to determine inclusion/exclusion into the study, data on age was not stored after enrollment. Gender, and race/ethnicity data was not collected as they are not relevant variables for the outcomes studied
| Characteristic | Unit | Bilateral Treatment With OpalSeal and Transbond XT |
|---|---|---|
| Participants analysed | 9 | |
| Age, Customized | Participants | NA |
| Sex/Gender, Customized: Sex not measured | Participants | 9 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: United States | participants | 9 |
6. Primary Endpoint
The registry lists the primary outcome as Loss of Mineral Density in the Enamel, measured over Time from initial bonding to extraction (max 90 days).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | microns |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is loss of mineral density in enamel, measured in microns as the depth of demineralized lesions. Teeth were to be assessed by microCT from initial bonding until extraction, with a maximum timeframe of 90 days. The posted results give a mean and a full range for each treatment group.
Lesion depth is used as a direct measure of the extent of enamel demineralization: greater depth indicates a deeper lesion in the measured tooth. MicroCT provides an imaging-based way to assess mineral changes in tooth tissue. This endpoint therefore captures a physical feature of early decay rather than a participant’s symptoms or a later clinical diagnosis. That is a general explanation of the measurement, not a claim about the study’s validation procedures, which are not reported in the registry record.
The registry reports a mean loss of mineral density of 70.8 microns for OpalSeal, with a full range from 0.0 to 130.5. For Transbond XT, the reported mean is 77.4 microns, with a full range from 0.0 to 245.3. The record states that 9 teeth in each group were available for analysis. It does not report a confidence interval or a statistical test for the group comparison. The range describes the lowest and highest observed measurements; it does not show the uncertainty around a group mean.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary endpoint summaries describe lesion depth in teeth assigned to OpalSeal or Transbond XT. The mean was 70.8 microns for OpalSeal and 77.4 microns for Transbond XT. The ranges were 0.0 to 130.5 and 0.0 to 245.3, respectively. Thus, the reported mean is lower in the OpalSeal group, while the observed values in both groups extend across a range. These descriptive summaries alone do not establish whether the difference between group means is distinguishable from sampling variability.
The endpoint population consisted of 9 teeth in each group, while the study enrolled 12 participants. Those counts describe different units: participants enrolled and teeth analyzed. The registry record does not report the number of participants contributing analyzed teeth, whether the same participants contributed to both groups, or the number of teeth contributed by each person. This information matters for interpreting precision because teeth from the same person may be more alike than teeth from different people. Whether that within-person dependence was handled in the analysis is not reported in the registry record.
No inferential analysis is listed in the registry record, and no p-value, confidence interval, adjusted estimate, or other model-based comparison is reported. The descriptive means and ranges can show the observed measurements, but they do not quantify uncertainty in the comparison. A confidence interval, in general, expresses the precision of an estimate under the assumptions of the method used; no such interval for the treatment contrast is reported. A p-value, in general, assesses compatibility of data with a specified null model; no p-value for the primary comparison is reported.
The primary endpoint is described as being assessed from initial bonding until extraction, up to a maximum of 90 days. The record does not give the actual measurement time for each tooth or report whether follow-up duration differed between groups. This limits assessment of how comparable exposure and observation time were. The range of observed lesion depths also does not explain whether measurements were skewed, whether outliers were present, or whether a mean was the most suitable summary.
The record lists zero participants at risk and zero affected for serious and other adverse events in both groups, and zero deaths. With zero recorded at-risk counts, these entries do not provide an interpretable safety comparison among exposed participants. The study’s small enrollment and the limited number of analyzed teeth also mean that these results describe a pilot dataset rather than a precise estimate for a broader orthodontic population. No clinical conclusion about benefit or lack of benefit follows from these summaries alone.
9. Statistical Methods Explained
The primary endpoint is reported as a mean with a full range, rather than as a treatment-effect estimate with an uncertainty interval. The registry gives the mean loss of mineral density and the lowest-to-highest observed values in each group. These summaries convey the center and extent of the observed measurements. They do not, by themselves, indicate how uncertain the difference between group means is or whether a formal comparison was performed.
What does a mean describe?
A mean is a measure of the central value of a set of observations. It is useful for a continuous outcome such as lesion depth, but it can be influenced by unusually high or low measurements. A range gives the observed endpoints and can make the spread of measurements visible, but it does not show how values are distributed between those endpoints. The registry reports full ranges, not standard deviations, standard errors, or interquartile ranges. It therefore does not provide those other descriptions of variability.
For OpalSeal, the reported mean is 70.8 microns and the full range is 0.0 to 130.5. For Transbond XT, the mean is 77.4 microns and the range is 0.0 to 245.3. These are summaries of the observed teeth. A contrast between treatment groups would ordinarily be accompanied by an estimate of uncertainty, especially when the number of analyzed units is limited. No confidence interval or formal test for this endpoint is reported in the registry record.
Why does the unit of analysis matter?
The enrollment count is 12 participants, while the primary endpoint population is 9 teeth in each group. If several teeth come from one participant, measurements from that participant may be correlated. In general, treating correlated teeth as if each were independent can make an analysis appear more precise than it is. A suitable analysis may account for the structure of the data, for example by using a paired or clustered approach when appropriate. Which approach was used is not reported in the registry record. Nor does the record clarify the number of participants who contributed teeth, or whether each participant contributed observations to both treatment groups.
The arm descriptions say that the side receiving OpalSeal was determined randomly for each participant, and that Transbond XT was applied on the other side for buccal surfaces. This description makes within-mouth comparisons relevant to understanding the design, but the registry’s model classification is single-group and its allocation is randomized. The record does not reconcile those classifications or identify the allocation unit in formal analytic terms. It is therefore not possible to determine from the registry record whether the reported group summaries were analyzed as independent groups, matched observations, or another design.
What do confidence intervals and p-values contribute?
In general, a confidence interval gives a range of estimates compatible with the data under a specified statistical method and assumptions. It communicates precision as well as the direction and size of an estimated contrast. A p-value is a measure of how compatible the observed data are with a specified null hypothesis, under the assumptions of a test. Neither quantity is reported for the primary comparison. Their absence means the posted summaries do not support a formal assessment of statistical uncertainty or statistical significance.
A statistically significant result, if one were reported, would not by itself establish clinical importance. Conversely, a nonsignificant result would not demonstrate equivalence or rule out a meaningful difference. Those are general statistical distinctions; the registry record does not report an equivalence margin, a noninferiority framework, or a hypothesis test for this endpoint.
How should planning calculations be understood?
Sample-size calculations are planning illustrations, not observed study outcomes. The registry’s stated illustration assumptions refer to a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects defined as fractions of the observed effect. They are explicitly planning calculations based on the observed effect, not the trial’s own design justification. No resulting participant-per-arm figures are reported in the registry record details for this study. Such illustrations do not indicate the probability that the completed study detected an effect, and they should not be described as observed power.
The registry does not report an a priori sample-size justification or explain the precision sought when enrolling participants. It also records zero analyses for the outcome results. The available statistics should therefore be read as descriptive endpoint summaries, without assuming an unreported model, adjustment, or inferential procedure. The calculations needed to make a new treatment contrast or uncertainty estimate are not part of the posted results and should not be substituted for a sponsor analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, including the primary endpoint of enamel mineral-density loss and two secondary outcomes: surface topography and hardness, and retention of OpalSeal. It reports 0 analyses. The registry record does not identify a statistical analysis for the primary endpoint or provide numerical results for the secondary outcomes. Values missing or not estimable for a two-arm comparison are noted for another endpoint.
When a study evaluates multiple outcomes or performs multiple tests, the chance of at least one false-positive finding can increase. General approaches to address multiplicity include identifying a primary outcome in advance, specifying a testing hierarchy, or adjusting inference across tests. Whether any such approach was planned or used is not reported in the registry record. Without reported tests or a stated multiplicity strategy, no claim about multiplicity-adjusted inference can be made.
The primary endpoint population is described as 9 teeth in each group, compared with 12 participants enrolled. The record does not explain why other teeth or participants were not included, whether data were missing, or how missing measurements were handled. It does not define an intention-to-treat, per-protocol, or other analysis population, nor state whether exclusions occurred. The record also does not report imputation or sensitivity analyses. These omissions limit assessment of potential selection or missing-data bias; they do not establish that missing data occurred or that any particular handling method was used.
11. What the Result Does, and Does Not, Mean
The result describes measured enamel lesion depths among the teeth available for the primary endpoint analysis. The mean was 70.8 microns for OpalSeal and 77.4 microns for Transbond XT, with full ranges of 0.0 to 130.5 and 0.0 to 245.3, respectively. The OpalSeal mean is lower in these descriptive summaries. Because no inferential comparison or uncertainty interval is reported, the summaries do not establish how precisely the treatment groups differ.
These data do not show that one primer prevents decay better than the other, and they do not show that the primers are equivalent. The study’s stated purpose was to evaluate whether a fluoride-releasing primer offered more protection against early decay than conventional primer during orthodontic treatment. A descriptive difference in group means is not sufficient to answer that comparative question without considering uncertainty, design, and analysis. No medical recommendation follows from these registry summaries.
The endpoint focuses on lesion depth in extracted teeth assessed by microCT within a maximum timeframe of 90 days. It does not, in itself, report long-term tooth health, clinical cavity diagnoses, symptoms, or outcomes beyond the measurement period. The registry record does not report the actual follow-up time for each tooth or provide results for the named secondary outcomes. Conclusions should therefore remain limited to the stated primary measurement and the available analyzed teeth.
The adverse-event entries list zero at risk and zero affected in both groups, as well as zero deaths. Since the registry lists no participants at risk in these categories, the entries do not establish that no adverse events occurred among participants who received the primers. Nor do they support a comparative safety estimate. The small pilot enrollment and the absence of inferential results further constrain what can be concluded from the record.
12. Why This Trial Matters Statistically
This study illustrates several statistical issues that can arise in small clinical investigations. The primary endpoint is measured in teeth, while enrollment is reported in participants. When multiple teeth are contributed by a participant, observations may be correlated. Clear reporting of the number of participants and teeth in each analysis, along with the analysis unit and any method for accounting for clustering or pairing, helps readers judge whether uncertainty has been estimated appropriately. Those analytic details are not reported in the registry record.
The treatment descriptions also make the comparison structure important: the side receiving OpalSeal was determined randomly for each participant, while Transbond XT was applied on the other side for the described buccal-surface procedure. At the same time, the registry identifies the model as single-group and reports two treatment arms. Explaining the relationship between design classifications, allocation, and analysis would help readers understand how the group summaries should be compared.
The endpoint summaries are means and full ranges, but no inferential comparison is posted. In general, reporting an effect estimate with a confidence interval helps communicate both the direction and precision of a comparison; a test result alone would not replace that information. A sample-size justification and details of the statistical analysis would also help distinguish study planning from post hoc illustrations. These matters are especially relevant in a pilot study, where descriptive estimation and feasibility may be more informative than a binary significance claim.
The record names two secondary outcomes but does not provide their numerical results or analyses. Reporting outcomes consistently, alongside how missing observations and multiplicity were handled, supports a transparent reading of the evidence. These are general reporting considerations, not claims about procedures that were or were not carried out outside the registry record.
13. 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 primary endpoint results are based on 9 teeth in each group, while 12 participants were enrolled. The registry record does not explain the relation between these counts, identify how many participants contributed teeth, or state whether individual participants contributed to both groups. Since the arm descriptions suggest a within-mouth allocation for at least some teeth, the lack of an explicit account of pairing or clustering is a specific interpretive limitation.
The record reports a mean and full range but no measure of uncertainty for the treatment comparison. No p-value, confidence interval, adjusted estimate, or analysis method is reported, and the record lists 0 analyses. It is consequently not possible to assess the precision of a group contrast or determine whether any statistical model accounted for the structure of the observations.
The primary outcome timeframe extends from initial bonding to extraction, with a maximum of 90 days, but actual measurement timing by tooth is not reported. The record does not explain whether follow-up was comparable between groups. It also does not report a sample-size justification, an analysis population definition, missing-data handling, or numerical findings for the named secondary outcomes.
The adverse-event record lists zero at risk in each group, limiting interpretation of its zero affected and death counts. The study is designated a pilot and has an enrollment of 12 participants; the available endpoint summaries should not be treated as a precise estimate for a wider population. The registry’s single-group model classification alongside randomized allocation and two reported arms also leaves the design description unresolved.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: An Evaluation of Protective Effects of OpalSeal™ Against Early Dental Decay in Orthodontic Patients — NCT03722264.
- Registry record last updated 2020-03-04; status last verified 2020-02.
- Results first posted 2020-02-25.
- 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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17. Record Summary
NCT03722264 is a completed pilot study titled “An Evaluation of Protective Effects of OpalSeal™ Against Early Dental Decay in Orthodontic Patients.” Virginia Commonwealth University is listed as sponsor. The registry records randomized allocation, double masking, a single-group model, and phase NA. Enrollment was 12 participants; the study started on 2017-11-16 and reached primary completion on 2019-04-12.
The primary endpoint was loss of mineral density in enamel, measured as lesion depth in microns by microCT from initial bonding to extraction, up to 90 days. The analysis population is described as 9 teeth in each group. Reported means and full ranges were 70.8 and 0.0 to 130.5 for OpalSeal, and 77.4 and 0.0 to 245.3 for Transbond XT. The record names surface topography and hardness and retention of OpalSeal as secondary outcomes. It does not report an inferential comparison for the primary endpoint.