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 MI Varnish for the Prevention of White Spot Lesions (NCT03446690), a non-randomized phase 4 study. The primary outcome is Enamel Decalcification Index (EDI) Scores.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03446690 |
| Phase | Phase 4 |
| Condition | White Spot Lesion, Orthodontic Treatment |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 62 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Alabama at Birmingham |
| Results posted | Yes |
2. Clinical Question
Population
Patients undergoing orthodontic treatment were the intended population. The registry describes 33 prospectively recruited subjects in the MI Varnish group and a control group of 29 orthodontically treated subjects. Participants were patients seeking orthodontic treatment at the University of Alabama at Birmingham’s Department of Orthodontics or School of Dentistry. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
The intervention was MI Varnish. The arm description says it was applied initially for 4 weeks (twice) and then at 3 monthly intervals. The exact timing and number of applications are not fully clear from that wording, so no more specific schedule can be inferred.
Comparator
The control group received routine orthodontic treatment and oral hygiene regimes. The registry describes no intervention for this group, but does not provide more detail about the routine care or hygiene instructions.
Primary question
The study aimed to assess whether EDI scores, an index of enamel decalcification and white spot lesions, differed between the MI Varnish group and the control group at Month 4. Higher EDI scores indicate more decalcification and a worse outcome. The registry record does not report group scores, an estimated difference, or an inferential analysis, so the comparative result cannot be determined from the posted record.
3. Trial Design
This was a completed, Phase 4, parallel-group study with non-randomized allocation and single masking. It enrolled 62 participants. The registry lists 33 subjects in the MI Varnish group and 29 in the control group. The sponsor was the University of Alabama at Birmingham. The study start date was 2015-01-01, and primary completion was 2015-11-01.
The intervention group was prospectively recruited and received MI Varnish as part of orthodontic treatment. The control group comprised orthodontically treated subjects who received routine treatment and oral hygiene regimes. Because allocation was non-randomized, the groups may have differed before treatment began. The registry does not describe how participants entered each group, whether matching or adjustment was planned, or whether the groups were comparable on important baseline characteristics. A non-randomized comparison therefore cannot, by itself, separate an intervention-related difference from differences in participant characteristics, care, or other factors.
Masking is recorded as single, but who was masked and how masking was maintained are not reported in the registry record. The study used photographic records and clinical examination to assess the outcome. The record describes photographs taken using a standard intra-oral camera, in a light-controlled environment and according to a preset photographic protocol. It does not specify whether the people assessing photographs or clinical examinations knew group assignments.
EDI scores were assessed at 1, 2, 3 and 4 months. Month 4 is identified as the reported time point, and the observation duration is described as an average of 4 months. Although the registry lists one primary outcome measure, no analysis or numerical outcome result is posted in the 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 | MI Varnish Group | Control Group |
|---|---|---|
| STARTED | 33 | 29 |
| COMPLETED | 26 | 29 |
| NOT COMPLETED | 7 | 0 |
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 | MI Varnish Group | Control Group | Total |
|---|---|---|---|---|
| Participants analysed | 26 | 29 | 55 | |
| Age, Continuous | years | 29.5 (SD 6.7) | 28.5 (SD 5.2) | 29 (SD 5.94) |
| Sex: Female, Male: Female | Participants | 16 | 16 | 32 |
| Sex: Female, Male: Male | Participants | 10 | 13 | 23 |
| Region of Enrollment: Central America | Participants | 18 | 20 | 38 |
| Region of Enrollment: Africa | Participants | 6 | 9 | 15 |
| Region of Enrollment: China | Participants | 2 | 0 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Enamel Decalcification Index (EDI) Scores, measured over Photographs were taken for 4 times at monthly intervals. EDI scores were measured and assessed at 1, 2, 3 and 4 months, Month 4 reported. The duration of the observation is an average of 4 months..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | scores on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was the Enamel Decalcification Index (EDI) score, a continuous score intended to represent enamel decalcification and the burden of white spot lesions. The facial surface of each tooth was divided into four areas: mesial, gingival, distal and occlusal. Each area received a score from 0, indicating no decalcification, to 3, indicating decalcifications covering 100% of that area. Scores across the four areas were aggregated at the tooth level to create an EDI for each tooth, potentially ranging from 0 to 12.
Higher EDI scores indicate more decalcification and represent a worse outcome. The registry describes using photographic records and clinical examination to assess the endpoint. It gives the endpoint summary measure as a mean with a 95% confidence interval, and identifies Month 4 as the reported time point after assessments at 1, 2, 3 and 4 months.
As a general statistical explanation, a continuous score can summarize variation in the measured amount of a condition across participants or teeth, depending on the analysis unit. A mean describes the average score, while a confidence interval conveys uncertainty around an estimated mean. The registry does not report the actual Month 4 means, confidence intervals, or enough detail to establish whether the analysis used participant-level summaries or another approach.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study question and the intended endpoint, but it does not report the endpoint results. No Month 4 EDI mean, confidence interval, comparison estimate, or analysis result is available in the posted record. The registry lists zero analyses. It is therefore not possible to describe the observed group difference, its direction, its magnitude, or its statistical uncertainty from the record.
The absence of a reported result is not evidence that the groups had identical EDI scores, nor does it establish that one group had higher scores. It also does not indicate whether an analysis was conducted outside the registry record. The appropriate reading is limited: the record describes measurement of EDI scores and a planned comparison, but does not provide the numerical comparison needed to interpret what happened to the endpoint.
Even if numerical means and confidence intervals were available, a mean alone would not show the spread or shape of individual scores. A confidence interval would help describe precision in the estimated mean, but it would not by itself resolve possible bias from non-randomized allocation. Baseline differences, differences in care, and differences in assessment could affect a group comparison. The registry does not provide the baseline data or an adjusted analysis that would help evaluate those issues.
The endpoint was assessed at 1, 2, 3 and 4 months, while Month 4 is identified as the reported time point. Repeated measurements can describe change over time, but their interpretation depends on how within-participant measurements and missing observations are handled. The registry does not report longitudinal results or the method used to account for repeated measurements.
The record reports no serious adverse events, other adverse events in the listed columns, or deaths in either group. These counts describe what the registry records; they do not provide a detailed account of all possible harms or establish that no event occurred outside the reporting definitions or observation period.
In short, the available information supports a description of the study design, endpoint, timing, and reported safety counts. It does not support a conclusion about the comparative EDI outcome. Any statement about whether MI Varnish changed white spot lesion scores would go beyond the result information in the registry record.
9. Statistical Methods Explained
The registry identifies EDI as a continuous outcome summarized by a mean and a 95% confidence interval. It does not report the numerical estimates or the statistical procedure used to compare the groups. The distinction matters: knowing the endpoint and its intended summary does not reveal the calculation, adjustment strategy, or result.
What a mean describes
As a general statistical explanation, the mean is an average of measured values. For this endpoint, the values are EDI scores constructed from decalcification scores across tooth areas. A group mean offers a compact description of the group’s average score, but it does not describe every participant’s or tooth’s score. It can be influenced by the distribution of scores and by the unit of analysis. The registry describes aggregation at the tooth level, but does not state how tooth-level values were combined or analyzed across participants.
How to read a confidence interval
As a general explanation, a confidence interval describes uncertainty in an estimate under the assumptions of the statistical method used. A narrower interval indicates greater precision than a wider interval, while neither width nor location alone establishes that an observed difference is important. The registry lists a 95% confidence interval as the dispersion measure for the primary endpoint, but no interval values are reported. It is also not reported in the registry record whether the intervals relate to each group mean or to a between-group contrast.
Non-randomized comparison
Allocation is recorded as non-randomized. In a randomized study, the allocation process is intended to balance measured and unmeasured characteristics across groups on average. In a non-randomized study, group membership may be related to participant characteristics, treatment choices, or other factors. A difference in endpoint scores can therefore reflect more than the intervention. Statistical adjustment can sometimes address measured differences, but cannot guarantee removal of unmeasured confounding. The registry does not report baseline comparisons, covariate adjustment, matching, or another strategy for addressing confounding.
Repeated measurements
EDI scores were assessed at 1, 2, 3 and 4 months, with Month 4 identified as the reported time point. As a general statistical matter, repeated observations from the same participant are related rather than independent. An analysis of multiple time points may need to account for that dependence. The registry does not report whether the analysis focused only on Month 4, modeled change over time, or used a method for correlated measurements. It also does not report any numerical results for the earlier assessments.
Precision and power
As a general explanation, a study’s ability to estimate a difference precisely depends on factors such as the number of participants, variability in the outcome, and the analysis method. The record gives an enrollment of 62 and describes 33 participants in the MI Varnish group and 29 in the control group, but it does not report a trial-specific sample-size justification or design assumptions. Any planning illustration based on an observed effect is not the same as a prospective justification and is not observed power. No such illustration can substitute for a reported treatment estimate and its uncertainty.
What cannot be reconstructed
The registry lists zero analyses and does not report a statistical analysis plan, a test statistic, a p-value, an adjusted estimate, an analysis population, or handling of missing observations. Those details should not be inferred from the fact that a mean and confidence interval were intended. Recalculations from summary statistics would also require posted numerical summaries, which the registry record does not contain. Accordingly, the statistical interpretation must remain descriptive rather than inferential.
10. Multiplicity, Missing Data and Analysis Populations
The endpoint was assessed at 1, 2, 3 and 4 months, and the registry identifies Month 4 as the reported time point. Repeated assessments create a general statistical issue: testing or emphasizing several time points can increase the chance of finding an apparently notable result by chance. A prespecified primary time point or a method that accounts for multiple comparisons can help address that concern. The registry record does not report whether a multiplicity strategy was planned, whether other time points were analyzed, or whether any adjustment was used.
The record lists one primary outcome measure, but this does not establish that only one statistical comparison was made. It does not provide a statistical analysis plan, a hierarchy of outcomes, or details of any additional analyses. The number of analyses listed in the registry is zero, so no analysis-level results are posted.
Missing-data handling is not reported in the registry record. There is no reported number of participants with Month 4 EDI data, no account of withdrawals or incomplete assessments, and no description of imputation or other methods for missing measurements. Without that information, it is not possible to assess whether the reported group results, if available elsewhere, would represent all enrolled participants or a subset with observed endpoint data.
The analysis population is also not reported in the registry record. The record does not say whether participants were analyzed according to their original group, according to the treatment received, or under another definition. These omissions limit assessment of how representative any endpoint estimate would be and how sensitive it might be to missingness or analysis choices.
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 |
|---|---|---|---|
| MI Varnish Group | 0 | 33 | 0.0% |
| Control Group | 0 | 29 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| MI Varnish Group | 0 of 33 |
| Control Group | 0 of 29 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| MI Varnish Group | 0 of 33 |
| Control Group | 0 of 29 |
The registry reports zero serious adverse events and zero deaths in both groups. It also reports zero events in the other adverse-event columns for the MI Varnish group and the control group. The listed at-risk counts are 33 for the MI Varnish group and 29 for the control group.
These figures should be read as registry-reported counts, not as proof that no adverse event of any kind occurred. The record does not give detailed definitions for the adverse-event categories, a narrative of events, or further information about surveillance and reporting procedures. It does not report whether the figures represent participants with at least one event or another counting convention. It also does not provide information about severity beyond the serious-event classification or a fuller account of event timing.
As a general statistical point, a zero count is an observation within a defined study and reporting system. It does not establish that the underlying risk is zero, especially when the number of participants and duration of observation are limited. The record describes an average observation duration of 4 months, but does not provide further safety follow-up detail. These counts therefore describe what is posted and should not be interpreted as a comprehensive guarantee of safety.
12. What the Result Does, and Does Not, Mean
The study record describes a non-randomized comparison of MI Varnish with routine orthodontic care, with EDI scores used to assess enamel decalcification and white spot lesions. It also describes the assessment schedule and the direction of the scale: higher scores indicate more decalcification and a worse outcome. These details clarify what the study set out to measure.
The record does not, however, report the primary outcome values or a statistical comparison. There is no reported Month 4 mean, confidence interval, or analysis result. Consequently, the posted information cannot establish whether EDI scores were higher, lower, or similar between groups, nor how precise any difference might be. A missing result should not be interpreted as a null result.
The design also matters to interpretation. Because allocation was non-randomized, differences between groups could reflect factors other than MI Varnish. The registry does not report baseline characteristics or adjusted analyses that could help evaluate this possibility. The single-masking designation does not specify who was masked, and the record does not say whether outcome assessors knew group assignments.
The reported adverse-event figures are zero in the listed event columns for both groups, including serious events and deaths. These counts describe the posted safety record but do not establish that all possible events were absent or assessed in the same way.
The most defensible conclusion is therefore about the limits of the registry entry: it documents the study question, groups, endpoint, timing, and safety counts, but not the comparative outcome result. It cannot support a claim about whether MI Varnish changed EDI scores or about the size or certainty of any difference.
13. Why This Trial Matters Statistically
This study illustrates why a clearly defined endpoint is only one part of an interpretable clinical trial record. The registry explains how EDI scores were constructed, what higher scores mean, and when measurements were planned. Those details make the clinical measurement more understandable, but they do not reveal the observed outcome without group estimates and uncertainty.
The non-randomized allocation is also statistically important. When participants are not allocated randomly, group comparisons may reflect differences that existed before treatment or factors associated with group membership. Readers need information about baseline characteristics and analytic adjustments to judge how much those factors may matter. Such information is not reported in the registry record.
Repeated assessments at 1, 2, 3 and 4 months highlight another common issue: results across time points need a clear analytic focus. A stated primary time point and a transparent approach to repeated measures and multiplicity help readers distinguish planned inference from exploratory comparisons. Those methods are not reported in the registry record.
Finally, the record distinguishes between a completed study and a reported analysis. It lists the study as completed and records enrollment, but the analyses count is zero and no primary outcome estimates are posted. This distinction is essential for statistical interpretation. Without numerical results, neither an effect estimate nor its precision can be evaluated, and a planning calculation cannot fill that gap.
The broader statistical lesson is that a useful registry record needs more than a study question and outcome definition. Readers also need transparent results, analysis details, and information about missing data and safety reporting to evaluate what the evidence does and does not show.
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 interpretation is that the registry record does not report any numerical EDI result or analysis. The primary endpoint is defined, but no group means, confidence intervals, or between-group estimate are available. This prevents assessment of the direction, magnitude, and precision of the comparison.
The comparison was non-randomized. The registry does not report how participants were assigned to groups, their baseline characteristics, or any method for adjusting for differences. Confounding therefore cannot be evaluated from the posted information. The control description refers to routine treatment and oral hygiene regimes, but does not give enough detail to establish how closely care was comparable across groups.
The record labels the study single-masked without identifying who was masked. It describes photographic records and clinical examination, but does not state whether image assessors or clinical examiners were blinded to group. The endpoint construction is described at the tooth level, while the method for analyzing scores across participants is not reported. This leaves the analytic unit and handling of within-participant or within-tooth dependence unclear.
Although EDI was assessed at 1, 2, 3 and 4 months, Month 4 is the identified reported time point. No earlier results, longitudinal analysis, multiplicity procedure, or missing-data method is reported. The registry also does not state the analysis population or provide counts of endpoint observations at each assessment.
Finally, the adverse-event entries contain zero counts in the listed categories, but the registry provides no detailed event definitions or fuller surveillance information. The study is described as having an average observation duration of 4 months; longer-term outcomes and safety information are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: MI Varnish for the Prevention of White Spot Lesions — NCT03446690.
- Registry record last updated 2023-06-26; status last verified 2023-06.
- Results first posted 2018-06-12.
- 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
This completed Phase 4, parallel-group study compared MI Varnish with routine orthodontic treatment and oral hygiene regimes. Allocation was non-randomized, masking was recorded as single, and enrollment was 62: 33 participants in the MI Varnish group and 29 in the control group. The sponsor was the University of Alabama at Birmingham.
The primary endpoint was mean Enamel Decalcification Index score, with a 95% confidence interval specified as the dispersion measure. Scores were assessed at 1, 2, 3 and 4 months; Month 4 was identified as the reported time point. Higher EDI scores indicate more decalcification and a worse outcome.
The registry record does not report endpoint values, a statistical comparison, or analysis methods; it lists zero analyses. It reports zero serious adverse events, other adverse events in the listed columns, and deaths in both groups. The available record supports description of the study design and measurement, but not a conclusion about the comparative EDI result.