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 Effect of GaAlAs 940 Laser on Pain and Wound Healing After Free Gingival Graft (NCT07308912), a randomized na study. The primary outcome is Postoperative Pain.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT07308912 |
| Phase | NA |
| Condition | Low Level Laser Therapy, Healthy, Postoperative Pain Management |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 34 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Medicine and Pharmacy at Ho Chi Minh City |
| Results posted | Yes |
2. Clinical Question
The clinical question is whether adjunctive photobiomodulation immediately after free gingival graft harvesting is associated with different postoperative pain and palatal donor-site healing outcomes than sham irradiation. The registered comparison is between a laser group and a control group receiving sham laser irradiation without therapeutic laser energy delivery.
Population
Adult patients undergoing free gingival graft surgery. The registry reports enrollment of 34 participants; the primary pain analysis included 33 participants after one participant in the laser group was excluded.
Intervention
A single application of 940-nm GaAlAs diode laser irradiation to the palatal donor site after suturing at the recipient site. The record describes 0.1-W power, energy density of 4 J/cm², continuous-wave mode, and exposure time of 40 s per field.
Comparator
Sham laser irradiation using the same procedure without therapeutic laser energy delivery. The control-group description also states that a palatal stent was subsequently placed.
Primary question
How do postoperative pain scores, measured at 2 hours, 3 days, and 7 days after surgery, compare between the laser and control groups? The registry also lists analgesic consumption and epithelialization outcomes.
The pain scale ranges from zero, equivalent to no pain, to 10, indicating the worst possible pain. The record identifies wound healing as another area of interest, including epithelialization and wound-size reduction in its trial description. However, numerical group results for pain, analgesic consumption, or healing are not reported in the registry record. The study question can therefore be described, but the posted record does not establish the direction, magnitude, or precision of any treatment-group difference.
3. Trial Design
The registry describes a randomized, triple-masked, parallel-group clinical trial. Participants were assigned to a laser group or a control group. The total enrollment was 34, and the study status is recorded as completed. The sponsor is the University of Medicine and Pharmacy at Ho Chi Minh City. The recorded study start was 2024-10-01, and the primary completion date was 2025-10-01.
The intervention was a single application of a 940-nm GaAlAs diode laser immediately after free gingival graft surgery. According to the arm description, irradiation occurred after suturing was completed at the recipient site. The settings listed are 0.1-W power, an energy density of 4 J/cm², continuous-wave mode, and an exposure time of 40 s per field. The control procedure used sham irradiation without therapeutic laser energy delivery; the control description also notes placement of a palatal stent.
The primary outcome was postoperative pain, expressed as a mean score on a scale, with standard error specified as the measure of dispersion. The recorded assessment times were 2 hours, 3 days, and 7 days after surgery. Secondary outcomes listed in the record include post-surgical analgesic consumption and epithelialization at D7 and D14. The trial description also mentions bleeding tendency, epithelialization, and wound-size reduction as healing-related measures.
One participant in the laser group was excluded from the primary pain analysis. The analysis included 16 participants in the laser group and 17 in the control group. The reason for exclusion, the randomization sequence and allocation-concealment procedures, and the operational details of masking are not reported in the registry record. Although the registry identifies the design as triple-masked, it does not specify which roles were masked. Numerical outcome results and analysis details are also 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 | Control Group | Laser Group |
|---|---|---|
| STARTED | 17 | 17 |
| COMPLETED | 17 | 16 |
| NOT COMPLETED | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: One participant in the laser group was excluded from the analysis; therefore, 33 participants (16 in the laser group and 17 in the control group) were included in the 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: Baseline characteristics are reported for the 33 participants included in the analysis. One participant assigned to the laser group was excluded from the analysis; therefore, the baseline analysis population comprised 16 participants in the laser group and 17 participants in the control group.
| Characteristic | Unit | Laser Group | Control Group | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 17 | 33 | |
| Age, Continuous | Years | 33 (23 to 43.25) | 34 (24 to 53) | 34 (23.5 to 48) |
| Sex: Female, Male: Female | Participants | 9 | 9 | 18 |
| Sex: Female, Male: Male | Participants | 7 | 8 | 15 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: Vietnam | Participants | 16 | 17 | 33 |
| Palatal donor site wound area | mm² | 152.28 (SD 93.23) | 166.24 (SD 55.94) | 160.33 (SD 75.18) |
6. Primary Endpoint
The registry lists the primary outcome as Postoperative Pain, measured over 2 hours, 3 days, and 7 days after surgery.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | scores on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is postoperative pain measured on a scale from zero, meaning no pain, to 10, meaning the worst possible pain. Pain was assessed at 2 hours, 3 days, and 7 days after surgery. The registry identifies the endpoint as a continuous measure summarized using a mean, with standard error listed as the dispersion measure.
Pain scores are used in clinical research to represent participants’ reported pain intensity at specified assessment times. A mean gives a group-level summary, while the underlying individual scores may vary. The standard error describes the precision of an estimated mean; it is not the same as the spread of scores among participants. A mean alone does not show how much participant responses differ from one another, and a standard error alone does not provide the full range of plausible treatment-group differences.
Repeated assessments can describe pain at different stages after surgery, but interpreting them requires the numerical results and clarity about how the observations were analyzed. The registry record does not report the group means, standard errors, treatment contrast, confidence intervals, or statistical tests for any assessment time. It therefore does not show whether pain scores differed between groups, how large any difference was, or how precisely a difference was estimated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes that the study was designed to compare a single 940-nm GaAlAs laser application with sham irradiation after free gingival graft harvesting. It also identifies postoperative pain at 2 hours, 3 days, and 7 days as the primary outcome and lists other outcomes related to analgesic use and epithelialization. These details describe the research question and planned measurements, not the trial’s findings.
Numerical results for the primary pain outcome are not reported in the registry record. There are no posted group means or standard errors, and no treatment-group contrast, confidence interval, or p-value is reported. Consequently, the record does not indicate whether the observed pain scores were higher or lower in either group, nor does it quantify the size or precision of a possible difference. The same limitation applies to the listed secondary outcomes: numerical results are not reported in the registry record.
The analysis population is described for the primary outcome: one participant in the laser group was excluded, leaving 16 participants in the laser group and 17 in the control group. This information clarifies who contributed to that analysis, but it does not explain why the participant was excluded or how the exclusion was handled in the analysis. The record does not identify the analysis population as intention-to-treat or per-protocol, and does not report how missing measurements were handled.
Completed status does not itself establish that results are available or that a particular effect was observed. Likewise, the absence of reported serious adverse events in the registry’s group figures is a description of those entries, not proof that no adverse events occurred or that every possible safety outcome was fully captured. The completeness and method of safety ascertainment are not reported in the registry record.
Any statistical interpretation should therefore remain limited to the design, analysis counts, and recorded safety figures. Without outcome estimates and their uncertainty, the registry record cannot support a conclusion about the size, direction, or statistical compatibility of treatment-group differences. A planning illustration based on an observed effect, if considered separately, is not a substitute for reported trial results and is not observed power.
9. Statistical Methods Explained
General statistical explanation: a randomized parallel-group design compares outcomes between groups assigned to different study procedures. Random allocation is intended to reduce systematic differences between groups at the start of a trial, on average. It does not guarantee that every participant characteristic will be balanced in a particular trial. The registry identifies this study as randomized, but the sequence-generation and allocation-concealment methods are not reported in the registry record.
What does a mean pain score represent?
General statistical explanation: a mean is a summary of the observed scores in a group. It can be useful for describing the average reported pain level, but it does not show the full pattern of individual responses. The registry states that pain was recorded on a scale whose endpoints are zero for no pain and 10 for the worst possible pain. It specifies a mean and standard error, but does not report the numerical group estimates.
A standard error describes uncertainty in an estimated mean due to sampling variation. It should not be read as the typical distance between individual participants’ scores. A measure of within-group variability, such as a standard deviation, would address a different question. The record specifies standard error as the dispersion measure but does not report the values needed to assess either group-level precision or participant-level variation.
How should a treatment contrast be interpreted?
General statistical explanation: a treatment contrast compares the outcome between intervention groups. The estimate describes the direction and magnitude of the observed difference, while a confidence interval expresses the uncertainty around that estimate under the statistical model. A confidence interval is not a guarantee that the true value lies within its limits; it is a method for showing the range of estimates compatible with the data and assumptions. No treatment contrast or confidence interval for pain is reported in the registry record.
A p-value, when reported, measures how incompatible the observed data are with a specified null model, under the assumptions of the analysis. It does not measure the probability that the null hypothesis is true, and it does not convey the clinical size of an effect. No p-value or statistical test result for the primary pain outcome is reported in the registry record. Without an estimate and its uncertainty, significance language would not be warranted.
Why do the assessment times matter?
General statistical explanation: measurements taken from the same participant over time are related. A participant’s score at one assessment may be associated with that participant’s score at another assessment. An analysis that accounts for this within-participant dependence can differ from an analysis that treats every measurement as unrelated. The registry lists pain assessment at 2 hours, 3 days, and 7 days after surgery, but does not report the statistical method used to analyze repeated measurements or whether each time point was analyzed separately.
Multiple outcomes and repeated assessment times also raise the general issue of multiplicity. When many comparisons are examined, the chance of obtaining at least one apparently unusual result can increase. A statistical plan may address this by identifying a primary comparison, adjusting inference, or treating some results as exploratory. The registry record identifies a primary outcome and lists secondary outcomes, but detailed multiplicity procedures are not reported in the registry record.
What can planning calculations tell readers?
General statistical explanation: sample-size planning uses assumptions about the effect to be detected, variability, significance level, and allocation. The planning illustration associated with this trial is described as based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It describes participants per arm for 80% power, and the stated planning approach uses fractions of the observed effect. Such calculations are illustrations, not evidence that the trial was designed around those assumptions, and not observed power. The registry does not report its own sample-size justification.
Over-dispersion is a general concern when outcomes vary more than a statistical model assumes. If a model understates variability, its uncertainty estimates can be too narrow and its inference too optimistic. This concept may be relevant to some types of outcomes, but the registry’s primary endpoint is a continuous pain score and no fitted model or variance diagnostics are reported. The registry record does not report enough analysis detail to assess model assumptions or their adequacy.
For this trial, the record reports the endpoint definition, the analysis counts, and the planned comparison context, but not the numerical outcome results or statistical analyses. The registered design therefore supports a description of what was studied, while the inferential results remain unavailable in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The trial includes pain assessments at 2 hours, 3 days, and 7 days after surgery, as well as listed secondary outcomes involving analgesic consumption and epithelialization at D7 and D14. Considering multiple outcomes or time points can make interpretation more complicated because repeated testing may increase the chance of an apparently notable result. General statistical approaches include defining a primary comparison in advance, adjusting for multiple tests, or treating secondary analyses as exploratory. The registry identifies postoperative pain as the primary outcome, but specific multiplicity procedures are not reported in the registry record.
The record states that one participant in the laser group was excluded from the primary pain analysis, leaving 16 participants in that group and 17 in the control group. The reason for exclusion and the handling of any missing outcome measurements are not reported in the registry record. The record does not say whether analyses followed intention-to-treat, per-protocol, or another population definition. Imputation methods, sensitivity analyses, and the amount or pattern of missing data are also not reported in the registry record.
The registry identifies the study as triple-masked but does not specify which participants or study personnel were masked, or how masking was maintained and assessed. It also does not report a detailed statistical analysis plan, interim analyses, or a sample-size justification. The planning illustration is not evidence of the trial’s own design assumptions and should not be interpreted as observed power. These omissions limit assessment of how the registered outcomes were analyzed and how robust any eventual findings would be.
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 |
|---|---|---|---|
| Control Group | 0 | 17 | 0.0% |
| Laser Group | 0 | 16 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Control Group | 0 of 17 |
| Laser Group | 0 of 16 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Control Group | 0 of 17 |
| Laser Group | 0 of 16 |
The registry’s adverse-event figures list zero serious adverse events, zero other adverse events, and zero deaths for the control group, with 17 participants at risk. The corresponding laser-group figures list zero serious adverse events, zero other adverse events, and zero deaths, with 16 participants at risk. These are the posted counts and denominators; they do not describe the nature or duration of safety monitoring.
Zero events in these entries means that no events are recorded in those categories for the listed groups. It does not establish that every possible event was sought, that all participants completed safety follow-up, or that the intervention cannot be associated with harm. The definitions used for serious and other events, the ascertainment procedures, the completeness of follow-up, and any assessment of causal relationship are not reported in the registry record.
The safety figures should therefore be read as registry entries rather than as a comprehensive estimate of risk. They do not replace detailed reporting of event types, timing, severity, and follow-up, none of which is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The trial record describes a randomized comparison of immediate 940-nm GaAlAs diode laser irradiation with sham irradiation after free gingival graft harvesting. It specifies a primary pain outcome measured at 2 hours, 3 days, and 7 days after surgery and lists additional outcomes related to analgesic use and epithelialization. This information establishes what the trial set out to examine.
The registry record does not report numerical results for pain or the listed secondary outcomes. It therefore does not show whether the groups had similar or different outcome values, what direction any difference took, or how precise an estimate might be. No conclusion about the magnitude or statistical uncertainty of a treatment effect can be drawn from the registered design and analysis counts alone.
The record reports that one laser-group participant was excluded from the primary pain analysis, with 16 laser-group and 17 control-group participants included. It does not provide the reason for that exclusion or enough detail to judge whether the analysis represents all randomized participants. The completion status and the recorded safety counts add information about the trial record but do not fill the gap in outcome results.
General statistical explanation: a study’s design and its results answer different questions. Randomization and masking describe how a comparison was intended to reduce bias, while estimates and uncertainty describe what the collected data indicate. Without the latter, it is not possible to assess whether an observed difference is small or large, or whether the data are compatible with a range of possible effects.
Any sample-size planning illustration should also be kept distinct from the trial’s observed outcomes. A calculation based on an observed effect is a planning exercise, not a result, and does not establish that the trial had adequate precision. The appropriate reading is limited: the registry describes the comparison and analysis population, but numerical clinical findings are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically relevant because it uses a randomized, masked comparison to study a focused procedural question: whether a single application of 940-nm GaAlAs laser irradiation after free gingival graft harvesting is associated with different postoperative pain and healing outcomes than sham irradiation. The design makes clear that the comparison concerns an adjunctive procedure at the palatal donor site, with pain assessed at specified postoperative times.
The endpoint also illustrates the distinction between a measurement schedule and a statistical result. Pain is recorded on a defined scale at 2 hours, 3 days, and 7 days after surgery. Those repeated assessments could describe how reported pain changes over time, but they require numerical outcome data and an analysis that accounts for the study structure. Neither the group results nor the analysis methods are reported in the registry record.
The record makes the analysis population visible: one participant in the laser group was excluded, leaving 16 participants in that group and 17 in the control group. This prompts questions about exclusion reasons, missing observations, and the population used for inference. Those details matter because interpretation depends not only on allocation but also on how participants and measurements contribute to the analysis.
The trial also highlights the role of complete reporting. A registered question, an identified primary outcome, and a completed status do not by themselves communicate an estimated effect. Reporting group estimates, between-group contrasts, uncertainty, and analysis decisions would be needed for readers to evaluate precision and interpret the findings. Without those results, the record supports discussion of trial design and reporting completeness, not conclusions about clinical effects.
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.
A central limitation of the available record is that numerical results are not reported for the primary pain outcome or the listed secondary outcomes. Group means, standard errors, treatment contrasts, confidence intervals, and p-values are not reported in the registry record. The direction, magnitude, and precision of any observed differences therefore cannot be assessed.
The primary pain analysis excluded one participant in the laser group. The reason for exclusion is not reported in the registry record, and the record does not describe whether the participant had missing measurements, withdrew, or was excluded for another reason. It also does not report how missing measurements were handled, whether sensitivity analyses were performed, or whether the analysis included all randomized participants.
Important design and analysis details are not reported in the registry record. These include the randomization sequence and allocation concealment, which roles were masked, the statistical methods used for pain assessments over time, procedures for multiplicity, interim analyses, and the trial’s own sample-size justification. The record specifies standard error for the primary endpoint but provides no numerical estimates or further account of the outcome distribution.
The registry lists secondary outcomes and describes healing measures, but does not provide their numerical results or detailed operational definitions in the record. Safety figures record zero serious and other adverse events and zero deaths in each listed group, but event definitions and safety-monitoring completeness are not reported in the registry record. These limitations constrain both efficacy interpretation and safety interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effect of GaAlAs 940 Laser on Pain and Wound Healing After Free Gingival Graft — NCT07308912.
- Registry record last updated 2026-10-08; status last verified 2026-09.
- Results first posted 2026-10-08.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed, randomized, triple-masked, parallel-group trial sponsored by the University of Medicine and Pharmacy at Ho Chi Minh City. Enrollment was 34. The trial compared a single 940-nm GaAlAs diode laser application after free gingival graft harvesting with sham laser irradiation.
The primary outcome was postoperative pain on a scale from zero for no pain to 10 for the worst possible pain, assessed at 2 hours, 3 days, and 7 days after surgery. The primary analysis excluded one participant in the laser group and included 16 laser-group and 17 control-group participants. Listed secondary outcomes include post-surgical analgesic consumption and epithelialization at D7 and D14.
Numerical outcome results and detailed statistical analyses are not reported in the registry record. The adverse-event entries list zero serious events, zero other events, and zero deaths in both groups.