Comparison Between Dexamethasone and Ibuprofen on Pain Prevention and Control Following Surgical Implant Placement: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison Between Dexamethasone and Ibuprofen on Pain Prevention and Control Following Surgical Implant Placement (NCT02763059), a randomized phase 4 study. The primary outcome is The Visual Analog Scale (VAS) Was Used to Measures Levels of Pain..

2. Clinical Question

The study summary describes pain and discomfort assessment after implant surgery. Pain was also assessed using the 101-point Numerical Rate Scale, while discomfort was assessed using a four-point Verbal Rating Scale. The registry record lists these as secondary outcomes, but their results are not reported in the registry record. The posted primary outcome therefore offers a limited view of the study's recorded pain assessments rather than a complete account of all planned measures.

3. Trial Design

The registry record describes a randomized, parallel-group, placebo-controlled clinical trial. Its masking classification is listed as triple, while the study summary describes the trial as double-masked. The registry record does not explain this difference or identify who was masked, so the exact masking arrangements are not reported in the registry record. The study is listed as Phase 4 and completed.

The study summary reports three protocols administered before surgery: ibuprofen, dexamethasone, or placebo. The active regimens each included a second dose 6 hours after the first. Rescue acetaminophen 1000 mg was available to participants in each group, with instructions to take it if necessary. The registry record does not report how often rescue medication was used or how its use was handled in the primary analysis.

Enrollment is listed as 132, and the summary reports 117 dental implants placed. For the posted primary outcome, the groups are labelled with outcome counts of 39 for ibuprofen, 43 for dexamethasone, and 35 for placebo. The arm descriptions elsewhere in the record say N=44 for each group. The registry record does not explain the difference between these arm-description counts and the counts accompanying the posted outcome results, or report whether the outcome counts reflect missing measurements, exclusions, or another accounting choice.

The primary outcome is a continuous VAS pain score, summarized by a mean and a 95% confidence interval for each group. The posted results give these group summaries at the 8 hours-time assessment. They do not give a comparative estimate, test statistic, or p-value for the primary outcome. The statistical analysis plan, model details, and treatment of repeated pain measurements are not reported in the registry record.

The study's listed start is 2013-09 and its primary completion is 2015-05. These dates describe the registry timeline; they do not, on their own, explain when participants were recruited or how long each participant was followed.

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

Reasons for not completing this period:

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 The Visual Analog Scale (VAS) Was Used to Measures Levels of Pain., measured over 8 hours-time.

The primary endpoint is pain intensity measured with the Visual Analog Scale (VAS). The description defines the scale as a 10-cm line whose ends represent “no pain” and “pain that could not be more severe.” A participant marks the point that best represents perceived pain, and the marked position is measured in centimeters to produce a score from 0 to 10. Lower scores indicate less perceived pain on this scale, while higher scores indicate more.

A continuous score preserves gradations in reported pain rather than reducing responses to a simple yes-or-no classification. Summarizing the scores with a mean gives a group-level description, while a confidence interval conveys uncertainty around that mean. These are general statistical functions of the summary measures; the registry record does not report why this endpoint was selected over the other pain or discomfort measures.

The registry record identifies the primary outcome timeframe as 8 hours-time. The study summary describes repeated pain assessments hourly for the first 8 hours after surgery and then three times a day on the following 3 days. It does not clarify how the 8 hours-time primary outcome relates to the full series of repeated assessments, including whether it represents a particular scheduled observation or a summary across observations. That endpoint detail is not reported in the registry record.

The posted results are group means with 95% confidence intervals. They do not include individual participant scores, a measure of within-group spread such as a standard deviation, or an adjusted comparison between groups. The endpoint therefore describes the posted average pain level at the specified timeframe, but does not by itself establish the size or precision of a treatment contrast.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure, so the posted result is expressed as a mean with a confidence interval rather than as a count of participants in categories. The VAS runs from 0 to 10, and its description states that lower scores represent less perceived pain. A mean provides a concise summary of the group scores, but it does not show how individual scores were distributed. For example, the same mean could arise from scores clustered near the average or from scores spread more widely. The registry record does not post the individual observations or a separate dispersion measure.

What does a confidence interval describe?

In general, a confidence interval communicates uncertainty about an estimate. Here, the posted intervals accompany the group means. They are not presented as confidence intervals for differences between groups. To assess a treatment contrast, readers need a direct estimate of that contrast and its uncertainty, ideally with the analysis method clearly described. The record does not report such an estimate for the primary outcome. Separate intervals around group means cannot be treated as though they were a direct comparison.

The posted means and intervals are 2.0 (95% confidence interval 1.08 to 4.4) for ibuprofen, 2.0 (95% confidence interval 1.57 to 3.0) for dexamethasone, and 5.0 (95% confidence interval 3.96 to 7.01) for placebo. These values let readers inspect the group-level summaries and their stated precision. They do not reveal the analysis model, whether any covariates were included, or how repeated observations were handled. Those methods are not reported in the registry record.

Why does the missing comparison matter?

A randomized design is intended to support comparisons between assigned groups, but the numerical group summaries alone are not the full inferential analysis. A comparative estimate would express how the groups differ under a defined method and quantify uncertainty in that contrast. The registry record says that values were missing or not estimable for a two-arm comparison of this continuous outcome. The posted information therefore supports describing each group's mean, but not presenting an official pairwise estimate or significance test.

This distinction also prevents overinterpretation of the observed numerical pattern. The two active-group means are both 2.0, and the placebo mean is 5.0. That is a description of the posted results, not a calculated treatment difference. No difference, ratio, or new summary should be inferred from those values in place of the absent comparative analysis. The sponsor's own analysis would take precedence if a discrepancy were reported; the registry record indicates no such discrepancy, but it does not supply an estimable comparison.

What is the role of the planning illustration?

The sample-size section uses the observed effect as a basis for planning illustrations. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. Such calculations ask what sample size a future study might require under the stated assumptions. They do not tell readers what power the completed trial actually had. Observed power is not an appropriate substitute for the uncertainty around an estimated effect, and the planning illustration is not the trial's own design justification.

The registry record does not report the trial's sample-size justification, the target effect used in the original design, or the procedure used to choose the planned enrollment. It also does not report whether the study included interim analyses or a prespecified stopping rule. Those omissions make it impossible to evaluate whether the original design had adequate planned precision from the registry information alone.

How should repeated measurements be understood?

The study summary describes pain assessments hourly for the first 8 hours after surgery and three times a day on the following 3 days. Repeated measurements from the same participant are generally related, rather than independent observations. As a general statistical matter, analyses of repeated measurements should account for that dependence when using more than one measurement per person. The registry record does not say whether the primary endpoint uses one scheduled score, a summary across observations, or a model of the repeated series. It also does not report any correlation structure or other modeling details. The 8 hours-time result should therefore be read as the posted endpoint summary, without assuming a particular repeated-measures method.

The study summary also says participants were instructed to use acetaminophen 1000 mg if necessary. Rescue medication can affect later pain scores, so its use and handling can be relevant to interpretation. This is a general consideration, not a claim about what occurred in this trial. The registry record does not report actual rescue-medication use or whether the primary analysis adjusted for it, treated it as part of the assigned protocol, or otherwise accounted for it.

The record lists two secondary measures: the 101-point Numerical Rate Scale for pain and the four-point Verbal Rating Scale for discomfort. The results for those measures are not reported in the registry record. Nor are detailed analysis methods, such as adjustment for multiple endpoints or a plan for missing measurements. These gaps limit assessment of how the primary result fits into the complete analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists the VAS as the primary outcome and also lists two secondary outcomes: pain measured by the 101-point Numerical Rate Scale and discomfort measured by the four-point Verbal Rating Scale. The results for those secondary outcomes are not reported in the registry record. The record does not report whether the analysis plan designated one primary comparison, how it handled the different treatment comparisons, or whether it adjusted for testing multiple outcomes. Without that information and the secondary results, readers cannot assess the role of multiplicity in the reported findings.

Multiplicity is a general statistical concern when several outcomes or comparisons are examined: the chance of seeing at least one apparently notable result can increase as the number of tests grows. Possible approaches include prespecifying a hierarchy or adjusting inference, but the registry record does not state whether any such approach was used. No particular method should be attributed to this trial.

The outcome counts shown with the primary results are 39 for ibuprofen, 43 for dexamethasone, and 35 for placebo, while each arm description states N=44. The registry record does not explain this difference or say whether missing outcome data, exclusions, or another reason accounts for it. It does not report the number or timing of missing primary measurements, reasons for missingness, or an imputation method. The analysis population is also not described: whether the results follow intention-to-treat, per-protocol, or another approach is not reported in the registry record.

These are not minor bookkeeping details. In general, missing observations and choices about which participants enter an analysis can affect both the estimate and its uncertainty. Without the trial's missing-data methods and analysis population, readers cannot determine how robust the posted summaries are to those choices. The registry record does not report a sensitivity analysis for missing outcome data.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 1% reporting threshold.

The posted safety figures show zero serious adverse events, zero other adverse events, and zero deaths in each outcome group. The counts at risk are 39 in the ibuprofen group, 43 in the dexamethasone group, and 35 in the placebo group. These are the groups and counts attached to the posted adverse-event results.

Read these figures as the events recorded in the registry results, not as proof that no adverse effects occurred. A zero count can reflect the events captured and reported under the registry's categories and observation period. The registry record does not report the safety follow-up period, event definitions, ascertainment procedures, or whether there were events that did not meet the listed categories. It also does not provide details about the severity or nature of non-serious symptoms beyond the zero counts.

The registry lists no top serious adverse-event terms. This means there are no such terms shown in the posted results; it does not independently establish the completeness of safety surveillance. The available figures are too limited to characterize the comparative safety profile of the protocols. In particular, they do not provide a formal between-group safety analysis or uncertainty estimates. They should be interpreted alongside the limited reporting context, rather than as a broad conclusion about safety.

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

The posted primary outcome gives a snapshot of group mean pain scores at the registry's 8 hours-time assessment. The mean is 2.0 for ibuprofen, 2.0 for dexamethasone, and 5.0 for placebo, with a 95% confidence interval reported for each group. Because lower VAS scores indicate less perceived pain, the group summaries show lower average scores in the two active-protocol groups than in the placebo group at this assessment. This statement describes the observed summaries; it is not a claim that either protocol caused a difference.

The registry record does not report an estimable two-arm comparison for the continuous endpoint. There is no posted comparative effect estimate, confidence interval for a contrast, or p-value for the primary result. Readers therefore cannot use this record alone to determine the statistical uncertainty around differences between the groups. Equal posted means for the active groups are not evidence of equivalence, and the different group means are not by themselves evidence of a statistically established effect.

The results also do not describe all the pain information collected. The summary describes repeated pain assessments across the first 8 hours and following 3 days, and the registry lists the NRS-101 and VRS-4 as secondary outcomes. Their results are not reported in the registry record. The primary endpoint's relationship to the broader time series is not clarified, and the record does not explain how rescue acetaminophen use was incorporated into analysis.

The available arm counts attached to the outcome differ from the N=44 shown in each arm description, and the record does not explain why. Missing-data handling and the analysis population are not reported. Those limitations constrain the interpretation of the posted averages, especially as a basis for comparing treatment groups.

The planning calculations elsewhere on the page are illustrations based on the observed effect and specified assumptions. They are not observed power, do not reconstruct the trial's original design rationale, and cannot substitute for the missing comparative analysis. The registry results support a careful description of the recorded means and intervals, but not a definitive comparative conclusion.

13. Why This Trial Matters Statistically

This trial illustrates why group summaries and treatment comparisons are not interchangeable. A registry can post a mean and confidence interval for each randomized group while not providing a direct estimate of the contrast that the clinical question asks about. The VAS results make the observed group averages visible, but the registry record says that values for a two-arm continuous comparison were missing or not estimable. That distinction is central to sound interpretation: descriptive patterns are informative, but they do not replace an inferential analysis.

It also highlights the importance of a clearly specified endpoint. The study summary describes pain assessment repeatedly over time, while the primary result is labeled 8 hours-time. When the relationship between the primary endpoint and the broader schedule is unclear, readers cannot tell whether the posted value corresponds to one observation or a summary of repeated measurements. Statistical methods should match the structure of the measurements, but the registry record does not report those methods.

The posted group counts and the counts in the arm descriptions also differ, without an explanation in the registry record. Transparent reporting of participant flow, analysis populations, and missing outcomes helps readers understand which data contribute to each result. Similarly, reporting rescue-medication use can clarify how pain measurements relate to the assigned protocols.

Finally, the sample-size section demonstrates the difference between planning and evaluation. Planning illustrations can explore the sample size needed under stated assumptions, but they are not evidence of the completed trial's power and do not substitute for a treatment estimate with uncertainty. The record's limits make this a useful example of how much statistical interpretation depends on complete reporting, beyond the headline means alone.

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 registry record does not report an estimable two-arm comparison for the primary continuous outcome. Although it posts group means and 95% confidence intervals, it provides no comparative estimate or p-value for the VAS result. This prevents assessment of the precision of a treatment contrast using the posted results.

The outcome counts are 39 for ibuprofen, 43 for dexamethasone, and 35 for placebo, whereas the arm descriptions state N=44 for each group. The reason for this difference is not reported in the registry record. Participant flow, the analysis population, and the handling of missing primary measurements are also not reported. These gaps make it difficult to establish how the posted summaries relate to all randomized participants.

The primary endpoint is labeled 8 hours-time, but the study summary describes repeated pain assessments hourly for the first 8 hours and three times a day on the following 3 days. The record does not clarify how the primary endpoint is derived from that schedule or report the method used to analyze repeated measurements. Use of rescue acetaminophen is described, but actual use and its role in the analysis are not reported.

There is also a difference in masking descriptions: the registry classification is triple, while the summary calls the study double-masked. The record does not reconcile these descriptions. The sample-size justification, detailed statistical analysis plan, interim analyses, missing-data sensitivity analyses, and multiplicity approach are not reported in the registry record. The secondary outcome results are also absent. Together, these reporting limits mean the posted results offer only a partial account of the study's statistical evidence.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Comparison Between Dexamethasone and Ibuprofen on Pain Prevention and Control Following Surgical Implant Placement — NCT02763059.
• Registry record last updated 2026-08-21; status last verified 2026-08.
• Results first posted 2025-10-29.
• 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.

18. Record Summary

The registry record describes a completed Phase 4 randomized, parallel-group, placebo-controlled trial comparing ibuprofen, dexamethasone, and placebo before surgical implant placement. Enrollment is listed as 132, and the study summary reports 117 dental implants placed. The primary endpoint is mean VAS pain score at the 8 hours-time assessment.

The posted means are 2.0 for ibuprofen, 2.0 for dexamethasone, and 5.0 for placebo, each with a 95% confidence interval. The registry record does not report an estimable two-arm comparison for this continuous outcome. The two listed secondary measures are NRS-101 pain and VRS-4 discomfort; their results are not reported in the registry record. The outcome counts differ from the counts in the arm descriptions, and the reason is not reported.

Interpretation is limited by the absent comparative analysis, unclear relationship between the primary assessment and the repeated measurement schedule, and unreported analysis population and missing-data methods. The posted safety results list zero serious adverse events, zero other adverse events, and zero deaths in each group, with limited context about ascertainment and follow-up.