Clinical Evaluation of 3M™ ESPE™ Adper™ Scotchbond™ SE Self-Etch Adhesive in Class I and Class II Restorations in Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Evaluation of 3M™ ESPE™ Adper™ Scotchbond™ SE Self-Etch Adhesive in Class I and Class II Restorations in Adults (NCT00658138), a randomized na study. The primary outcome is Percentage of Restorations Scoring Alpha.

2. Clinical Question

The study’s stated purpose was to evaluate the performance of a new dental adhesive system for restoring adult teeth with Class I and Class II cavities. The clinical comparison is between the two listed adhesive systems. The primary outcome focuses on restoration scores, rather than a patient-level measure: restorations were graded Alpha, Bravo, or Charlie across retention, post-operative sensitivity, anatomic form, margin integrity, color match, stain resistance, and secondary caries. Alpha was described as excellent, Bravo as acceptable, and Charlie as unsatisfactory. The primary result is the percentage of restorations receiving Alpha scores.

The reported outcome values are 100.0 for Scotchbond SE and 96.0 for Scotchbond 1XT. The registry states that the analysis was based on study teeth available for review at 12 months. It does not report a confidence interval for these arm-specific percentages. Nor does it report the number of teeth available in each arm separately as a distinct outcome-analysis denominator; the arm counts accompanying the results are 40.0 for each group. These details matter when interpreting the percentages and the accompanying analyses.

The registry record identifies randomized allocation, single masking, and a parallel model. It does not give enough detail to establish who was masked or how assignment was implemented. The clinical question can therefore be framed as a comparison of the recorded Alpha-score percentages, while keeping the reported outcome population, analysis details, and information gaps in view.

3. Trial Design

The registry describes a randomized, single-masked, parallel-group study of two dental adhesive devices: 3M ESPE Adper Scotchbond SE and 3M ESPE Adper Scotchbond 1XT. The condition listed is dental caries. The stated study purpose concerns the performance of a dental adhesive system in adult Class I and Class II restorations. The registry record lists enrollment as 61 and gives the study status as completed. The recorded start and primary completion dates are 2008-12 and 2010-11.

The registry lists Scotchbond SE and Scotchbond 1XT as the outcome arms, with 40.0 shown for each arm in the primary outcome results. Those arm counts should not be treated as a reconciliation of the enrollment figure: the registry describes the primary outcome population as study teeth available for review at 12 months, and does not explain how the enrollment figure relates to the arm counts in the outcome display. It also does not report the number of participants or study teeth with outcome data separately by arm beyond the counts displayed with the results. Restorations and people are not necessarily interchangeable units, so the outcome’s stated unit and analysis population should be kept distinct from the overall enrollment.

Although the record calls the study single-masked, the identity of the masked party is not reported in the registry record. Further details about randomization, concealment of assignment, the treatment protocol, and the conduct of follow-up are also not reported in the registry record. The phase entry is NA, and the registry classifies the interventions as devices.

The posted results include a primary outcome at 12 months and two reported statistical analyses. The registry does not report a detailed statistical analysis plan, the planned sample-size justification, or whether interim analyses were planned or conducted. Without those details, the design description supports a cautious account of the reported comparison, but not a reconstruction of all intended trial procedures.

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: All enrolled participants took part in the study

Overall Study

Analysis population for the primary outcome, as defined in the registry: Analysis was based on the number of study teeth available for review at 12 months

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Restorations Scoring Alpha, measured over 12 months.

The primary endpoint is the percentage of restorations scoring Alpha at 12 months. The scoring system classified restorations as Alpha, Bravo, or Charlie for retention, post-operative sensitivity, anatomic form, margin integrity, color match, stain resistance, and secondary caries. Alpha was defined as excellent, Bravo as acceptable, and Charlie as unsatisfactory. The primary endpoint uses total Alpha scores; it is therefore a summary of the most favorable score category across the listed restoration criteria, rather than a separate reported estimate for each criterion.

This kind of endpoint provides a structured way to describe the observed condition of restorations at follow-up. In general, a categorical clinical score can make several aspects of performance interpretable through a common grading framework. A percentage expresses how much of the analyzed set falls into the specified category, but does not by itself describe the severity or pattern of scores outside that category. The registry record does not provide separate percentages for Bravo and Charlie in the primary outcome display, nor does it give criterion-specific outcome values.

The outcome population is described as the number of study teeth available for review at 12 months. That wording is important: the endpoint reflects restorations available for assessment at follow-up, and the record does not describe how unavailable assessments were handled. It does not report a participant-level endpoint, an estimate adjusted for other factors, or a confidence interval around either arm’s percentage.

The registry reports 100.0 for Scotchbond SE and 96.0 for Scotchbond 1XT. These are descriptive arm-specific values. Their interpretation depends on the underlying scoring, outcome availability, and analysis method. The endpoint is useful for describing the recorded Alpha-score frequency, but the percentages alone cannot establish how precisely the groups differ or whether the comparison meets a prespecified clinical criterion.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports use of the Wilcoxon (Mann-Whitney) method for both listed analyses. This is a rank-based approach to comparing observations between groups. In general, rank methods use the ordering of observed values rather than relying directly on a normal distribution model for those values. The method can be useful when outcome distributions do not fit assumptions associated with a conventional comparison of means. However, its interpretation depends on the data structure, the endpoint, and the exact statistic used. The registry does not report enough detail to establish precisely how the test was applied to the restoration scores or how observations were represented in the analysis.

What does the reported test compare?

The first entry is labelled Mean Difference (Final Values), but the method is Wilcoxon (Mann-Whitney). The record gives an analysis value of 0.05 and p = 0.05, without confidence limits. The second entry is labelled percentage of Alpha values and reports p > 0.05, with 95 as the confidence level but no lower or upper limits and no effect estimate. These labels do not fully specify the test statistic, the null hypothesis, or the scale on which the comparison was performed. The registry does not report a detailed statistical analysis plan that resolves these questions.

In general, the Mann-Whitney procedure compares the relative ordering of observations in two independent groups. It is sometimes described as a test of differences in distributions, and under additional assumptions can be interpreted in relation to a location shift. It is not automatically a test of the difference between arithmetic means. When outcomes are binary, categorical, clustered, or summarized as percentages, it is especially important to know what observations entered the test and how the test statistic was defined. The registry’s short labels do not provide that information.

How should the p-values be read?

In general, a p-value measures the compatibility between observed data and a null model, conditional on the assumptions of the analysis. It is not the probability that the null hypothesis is true, and it does not state the probability that the findings are due to chance. A p-value also does not quantify the size of an effect or its practical importance. The reported p = 0.05 and p > 0.05 should therefore be read alongside the endpoint values and the limitations of the report, rather than as stand-alone conclusions.

The second analysis is given a 95 confidence level, but the registry does not give the confidence interval endpoints. A confidence interval, in general, is a range of values compatible with the data under a specified method and assumptions. Its width conveys information about precision, while its location helps show which effect values remain plausible. Without the limits, readers cannot judge the range or precision of the reported comparison from that entry. The arm percentages also lack confidence limits.

What is missing for a non-inferiority or equivalence interpretation?

Non-inferiority and equivalence questions require a prespecified margin that defines how large a difference can be while still supporting the intended conclusion. They also require an estimate and uncertainty interval interpreted in relation to that margin. The registry labels the entries as legacy non-inferiority or equivalence analyses, but the margin and decision rule are not reported in the registry record. No confidence limits are posted for the mean-difference entry, and the second entry supplies no interval endpoints. The labels alone are not enough to determine whether the intended criterion was satisfied.

In general, failure to find evidence of a difference is not the same as evidence that two treatments are equivalent. An equivalence conclusion requires sufficient precision to rule out differences larger than the prespecified acceptable range. A non-inferiority conclusion likewise depends on the direction of the comparison, the margin, and an appropriate confidence interval. Those elements cannot be reconstructed from the registry’s abbreviated entries.

Why do the outcome unit and analysis population matter?

The primary measure is a percentage of restorations scoring Alpha, and the record says the analysis was based on study teeth available for review at 12 months. A percentage is interpretable only in relation to its denominator and the way observations were selected. The registry lists 40.0 in each arm, but does not explain the relationship between those counts, the enrollment of 61, and the number of teeth available for review. It also does not state whether more than one restoration could contribute per participant or how any within-participant dependence was handled. Those details are not reported in the registry record.

In general, observations from the same person can be correlated. If the analysis treats correlated observations as independent, uncertainty estimates may not reflect the actual information in the data. The registry does not provide enough information to evaluate this issue. It also does not report how missing follow-up assessments were handled, whether an intention-to-treat or per-protocol population was used, or whether sensitivity analyses were conducted.

The outcome is described as count other, and the posted summary does not support a recalculated two-arm estimate. In general, a recalculation requires compatible information about the outcome scale, group denominators, and statistical assumptions. A percentage alone, especially without complete analysis-population detail and uncertainty estimates, is not a substitute for the underlying observations. The registry does not report the data needed to reproduce the sponsor’s analysis or independently estimate a confidence interval for the comparison.

Finally, a statistical analysis plan, sample-size justification, and interim-analysis details are not reported in the registry record. In general, a prespecified plan helps readers distinguish planned analyses from exploratory analyses and understand how multiple outcomes or tests were handled. Without it, the two reported tests cannot be placed within a documented hierarchy, and the role of any multiplicity adjustment cannot be determined.

10. Analyses Reported by the Sponsor

The registry’s reported analyses are the available sponsor-reported inferential results: a Wilcoxon (Mann-Whitney) analysis labelled mean difference in final values, with a reported value of 0.05 and p = 0.05, and an analysis labelled percentage of Alpha values, with p > 0.05 and a stated 95 confidence level. The registry does not provide confidence limits for either entry. The second entry also does not give an effect estimate. These abbreviated results do not fully describe the analysis or establish a non-inferiority or equivalence conclusion, because the margin and decision rule are not reported in the registry record.

No recalculated two-arm estimate is available from the posted summary. The endpoint is classified as count other, and the registry does not provide a single estimable comparison for an independent recalculation. Consequently, there is no recalculated result to compare against the sponsor’s analyses. The arm percentages remain useful descriptive results, but they do not supply the missing inferential details.

The registry does not flag a discrepancy between a sponsor analysis and a recalculation. The sponsor’s own analysis therefore remains the reported analysis, but its interpretation is limited by the details absent from the record. It should not be supplemented with a new estimate derived from the available percentages alone. A fuller assessment would require the analysis definition, underlying data or sufficient summary statistics, the prespecified margin if applicable, and confidence limits.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and two reported analyses. It does not list secondary outcomes in the posted results. The presence of more than one reported analysis does not, by itself, establish whether the tests were planned as a family, whether one was primary and the other supportive, or whether any adjustment for multiple testing was intended. A statistical analysis plan and a multiplicity procedure are not reported in the registry record.

In general, multiplicity arises when several outcomes, time points, groups, or statistical tests are considered. Repeated testing can increase the chance of a nominally notable result even when no underlying effect exists. An analysis plan may address that concern by specifying a testing hierarchy, adjusting significance thresholds, or defining a single primary contrast. The registry record does not indicate whether any of these approaches was used. The two reported entries should therefore be read as separate registry results, without assuming they were adjusted or that one supersedes the other.

The record states that the primary outcome analysis was based on study teeth available for review at 12 months. It does not report the number of missing assessments by arm, reasons for missingness, or the method used to handle unavailable assessments. In general, missing outcome data can affect both the estimated result and its uncertainty, particularly if availability is related to outcome status or treatment group. The posted percentages cannot resolve that concern without details of the outcome denominators and follow-up.

Analysis-population definitions are also not reported. The record does not say whether the reported analyses followed an intention-to-treat principle, a per-protocol principle, or another defined population. It does not describe exclusions, deviations, or sensitivity analyses. The listed arm counts of 40.0 each do not explain their relationship to the enrollment figure of 61, and the record does not clarify whether the analyzed units were participants, teeth, or restorations in all parts of the analysis. Those distinctions are relevant to interpreting both point estimates and uncertainty.

These gaps do not show that missing-data, multiplicity, or analysis-population methods were handled improperly; they mean the registry record does not document how they were handled. As a result, readers cannot assess those elements of the statistical approach from the posted information.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event entry combines 3M ESPE Adper Scotchbond SE and 3M ESPE Adper Scotchbond 1XT in one group. It lists 61 at risk for serious adverse events and zero serious adverse events. It also lists 61 at risk for other adverse events and zero other adverse events. The record does not give separate safety counts by adhesive, so the figures cannot be used to compare the arms.

These counts are limited to the categories and reporting shown in the registry. The record does not list serious adverse-event terms, and deaths are not reported in the registry record. Zero recorded events means that no events were entered for these categories in the posted results; it does not demonstrate that no events occurred outside the reporting captured by this record or that risk is absent.

In general, safety counts should be interpreted with attention to the population observed, follow-up duration, event definitions, and completeness of reporting. The registry’s safety entry does not describe event ascertainment or provide detail sufficient to assess those matters. The combined-group format also prevents attribution of the counts to either adhesive. These limitations call for a narrow reading of the figures as registry-reported counts, not a comparative safety conclusion.

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

The posted primary outcome describes the proportion of restorations scoring Alpha at 12 months: 100.0 for Scotchbond SE and 96.0 for Scotchbond 1XT. The registry identifies Alpha as excellent within a grading system that also included Bravo, acceptable, and Charlie, unsatisfactory. These values summarize the recorded outcome among study teeth available for review. They do not provide a complete account of every scoring category or every criterion used in grading.

The result does not establish that one adhesive is better than the other. The registry does not report confidence limits for the arm percentages, and its inferential entries do not provide enough information to evaluate precision against a clinically meaningful threshold. In particular, the record does not report a non-inferiority or equivalence margin. A p-value greater than 0.05 is not proof that groups are identical, while a value at a conventional threshold is not, by itself, evidence of an important treatment effect.

The result also does not show how the outcome might differ among people or settings beyond the study description. The registry does not report enough information about participant eligibility, clinical procedures, outcome availability, or analysis populations to assess the reach of the findings in detail. Nor do the posted percentages alone explain whether outcomes were correlated within participants, how missing follow-up was handled, or how many restorations were assessed under each scoring criterion.

The safety entry reports zero serious and zero other adverse events in a combined group, but does not separate counts by adhesive. It cannot establish comparative safety or rule out uncommon events. More broadly, absence of a recorded event in the posted results should not be interpreted as evidence that an event is impossible.

The most defensible reading is therefore descriptive: the registry reports high Alpha-score percentages for both adhesive groups at 12 months and provides limited statistical and safety detail. The data do not support claims of superiority, equivalence, non-inferiority, or absence of risk without the additional design and analysis information needed to evaluate those claims.

14. Why This Trial Matters Statistically

This study illustrates why a high outcome percentage and a clear treatment conclusion are not the same thing. The registry reports Alpha-score percentages of 100.0 and 96.0, but does not provide confidence limits around those values. Without a measure of uncertainty, readers cannot judge how precisely the reported percentages represent outcomes in the study population or how much uncertainty surrounds their comparison.

It also shows why analysis labels need to be accompanied by definitions. The registry names the Wilcoxon (Mann-Whitney) method and labels an entry as a mean difference in final values, but does not give the full test specification or confidence limits. The other entry reports p > 0.05 without an effect estimate or interval endpoints. These details are particularly important when a record labels analyses as non-inferiority or equivalence: the margin and decision rule determine what evidence is required for those conclusions.

The endpoint’s unit and population are also central. A percentage of restorations scoring Alpha is not necessarily the same as a percentage of participants with a particular outcome. The registry says the analysis used study teeth available for review at 12 months, while the displayed arm counts and overall enrollment are not reconciled in the record. Understanding the relationship among participants, teeth, and restorations is necessary to assess denominators and the assumptions used for inference.

Finally, the record demonstrates the limits of interpreting sparse safety reporting. A combined-group zero count does not permit a comparison between the adhesives, and the registry provides no event terms or separate arm-level safety counts. Taken together, these features make the study statistically informative as a case in interpreting endpoint definitions, test labels, precision, and reporting completeness, while underscoring the distinction between descriptive values and a well-supported comparative conclusion.

15. 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.

Several limitations of interpretation arise specifically from the registry record. The primary outcome is defined as a percentage of restorations scoring Alpha, and the analysis population is described as study teeth available for review at 12 months. The record does not explain how many outcome assessments were available by arm beyond the listed arm counts, or how those counts relate to the enrollment of 61. It also does not clarify whether the analysis unit was a participant, tooth, or restoration throughout the reported analyses.

The outcome definition combines several clinical criteria into the Alpha-score summary. The registry gives no separate results for retention, post-operative sensitivity, anatomic form, margin integrity, color match, stain resistance, or secondary caries. The percentages therefore do not show whether the component criteria had similar patterns or which criteria contributed to non-Alpha scores.

The inferential information is incomplete. The registry reports two Wilcoxon (Mann-Whitney) analyses with short labels, but does not describe the exact test statistic or give confidence limits for the arm-specific percentages. The mean-difference entry has no confidence limits, and the percentage-of-Alpha entry gives no effect estimate or interval endpoints. The non-inferiority or equivalence margin and decision rule are not reported in the registry record.

There is also no documented detail about missing-outcome handling, analysis populations, multiplicity, a statistical analysis plan, sample-size justification, or interim analyses. The absence of these details in the record does not establish that the methods were not used; it limits independent assessment of them. The single-masked designation does not identify who was masked, and further details of randomization and assignment procedures are not reported.

Finally, the safety results are combined across the two adhesive systems, preventing arm-specific interpretation. Deaths are not reported in the registry record. These limitations mean the posted results can be described, but claims about precision, comparative safety, generalizability, or non-inferiority and equivalence require information not contained in the record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Evaluation of 3M™ ESPE™ Adper™ Scotchbond™ SE Self-Etch Adhesive in Class I and Class II Restorations in Adults — NCT00658138.
• Registry record last updated 2024-10-02; status last verified 2024-09.
• Results first posted 2012-03-26.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed, randomized, single-masked, parallel study of Scotchbond SE and Scotchbond 1XT for adult Class I and Class II restorations. Enrollment is listed as 61. The primary outcome is the percentage of restorations scoring Alpha at 12 months, based on study teeth available for review.

The reported Alpha percentages are 100.0 for Scotchbond SE and 96.0 for Scotchbond 1XT. Two Wilcoxon (Mann-Whitney) analyses are listed: one reports a mean difference in final values of 0.05 with p = 0.05, and another reports p > 0.05 for percentage of Alpha values. The record does not provide confidence limits for the arm percentages, the analysis margins, or full details needed to interpret the entries as non-inferiority or equivalence findings.

Safety counts are reported for a combined adhesive group, with zero serious and zero other adverse events among 61 at risk in each category. The record does not provide separate safety counts by adhesive. Missing-data handling, analysis populations, multiplicity procedures, and additional statistical-plan details are not reported in the registry record.