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 Histopathological Evaluation of the Periodontal Ligament Subjected to Laser Ablation. (NCT06173648), a na na study. The primary outcome is Cell Count of Inflammatory Infiltrate Per Cross-Sectional Area at 400X Magnification.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06173648 |
| Phase | NA |
| Condition | Pulp Necroses |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | CAO Group, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned mandibular incisor teeth from people whose teeth were to be extracted for other reasons. The registry lists enrollment of 10. The primary outcome description refers to teeth, while the brief summary describes tissue examination after treatment; the record does not give further details about the number of teeth contributing to each outcome.
Intervention
The intervention was laser ablation using an 810nm diode laser with an indocyanine green (ICG) solution. The registry describes the intervention as laser and ICG solution. The brief summary explains that ICG absorbs laser energy and describes the study as examining possible effects on structures outside the tooth root.
Comparator
The registry describes control teeth not exposed to laser and ICG solution, and the brief summary refers to non-treated controls. The record does not describe a randomized allocation: allocation is listed as NA, and the study is classified as a single-group model. The registry cautions that the arms are not a like-for-like control comparison.
Primary question
The primary outcome was the cell count of inflammatory infiltrate per cross-sectional area at 400X magnification, with the measurement expressed as cells per 0.1 mm^2. It was assessed 28 days after intervention. The question was whether the amount of inflammatory infiltrate in treated tissue differed from that in control tissue. Numerical outcome results are not reported in the registry record.
3. Trial Design
This completed study examined histological and morphological changes in extracted teeth after laser ablation with ICG. The registry lists the design model as single group, allocation as NA, and masking as NONE. Although control teeth are also described, the registry explicitly cautions that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The record therefore should not be read as a conventional randomized, parallel-arm trial.
Enrollment is listed as 10. The study population is described as mandibular incisor teeth that required extraction for other reasons. The arm description says that study participants' teeth were accessed, filed, subject to pulp extirpation, and treated with endodontic solutions before some teeth received the study intervention. The registry record does not report the full procedural details for each tooth or how teeth were assigned to exposure or control conditions.
The intervention is identified as a device, named as laser and ICG solution. The brief summary specifies an 810nm diode laser and says the study aimed to observe possible changes in periodontal ligament and cementum outside the root. The primary outcome timeframe was 28 days after intervention. The registry lists the study as completed, with a start date of 2023-08-01 and a primary completion date of 2023-10-23.
The listed phase is NA. The record does not report a sample-size justification, a detailed statistical analysis plan, or the method used to handle the nonrandomized comparison. These omissions limit assessment of how the study was planned and how strongly the findings can support comparisons between treated and control teeth.
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: There were no issues with participant wash-out after initial acceptance into the study.
Overall Study
| Stage | Teeth Exposed to Laser and ICG Solution. |
|---|---|
| STARTED | 10 |
| COMPLETED | 10 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Mandibular incisor teeth
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: A total of 10 participants were involved in the study. All 10 participants contributed 1 tooth to the interventional group. Additionally, 2 of the participants contributed an additional tooth that was subject to the control treatment conditions.
| Characteristic | Unit | Teeth Exposed to Laser and ICG Solution. |
|---|---|---|
| Participants analysed | 10 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 10 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 4 |
| Region of Enrollment: Brazil | participants | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Cell Count of Inflammatory Infiltrate Per Cross-Sectional Area at 400X Magnification, measured over 28 days after intervention..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Cells / 0.1 mm^2 |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the cell count of inflammatory infiltrate within a cross-sectional area viewed at 400X magnification. The unit is cells per 0.1 mm^2, and the assessment was scheduled for 28 days after intervention. Inflammatory cells are a histological sign of tissue response to injury; counting them provides a way to describe and compare the amount of inflammatory infiltration in examined tissue. The registry frames the measurement as a comparison between cells reacting to injury after the investigational treatment and cells reacting to the control treatment.
The endpoint is a count measured within a defined area, rather than a clinical symptom or a direct measure of treatment benefit. The registry identifies the measure as a mean with standard deviation as its dispersion summary. A mean describes the average count across the observations included in an analysis, while the standard deviation describes how dispersed those observations are around the mean. These summaries would help readers understand both the overall level and variability of the measured cell counts.
However, the numerical mean and standard deviation for this endpoint are not reported in the registry record. Nor are the group sizes contributing to the endpoint, a between-group estimate, or a confidence interval. The brief summary reports a qualitative finding of no difference in examined structures compared with non-treated controls, but it does not provide the cell-count values needed to assess the primary endpoint's magnitude or precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry's brief summary states that histological and morphological examination of extracted cementum, ligament, and collagen after exposure showed no difference in these structures compared with non-treated controls. This is a qualitative statement. It does not report numerical measurements for the primary endpoint, the cell count of inflammatory infiltrate per cross-sectional area at 400X magnification. It also does not provide a statistical estimate of the difference between treated and control teeth.
Because the cell-count means and standard deviations are not reported in the registry record, readers cannot determine the observed scale or variability of that outcome. A confidence interval, p-value, or other inferential result for the primary endpoint is also not reported in the registry record. Without an estimate and a measure of precision, the qualitative phrase “no difference” cannot establish how closely the results align with no difference, or how much uncertainty remains around the comparison. It should not be interpreted as evidence that the groups were equivalent.
The study's comparison also needs caution because the registry describes a single-group model, lists allocation as NA, and flags the arms as not a like-for-like control comparison. The control teeth were not described as a randomized comparison group. Differences in how teeth entered the exposed and control groups could therefore complicate interpretation of any contrast, even if numerical results were available. The registry does not report enough information to assess whether, or how, such differences were addressed.
The adverse-event listing gives a separate descriptive snapshot: the exposed group has 10 at risk and the control group has 2 at risk, with zero serious events, zero other events, and zero deaths listed in each group. These figures concern safety listings, not the primary histological endpoint. They should not be used to infer the number of teeth included in the primary endpoint analysis.
The posted summary may be informative as a description of what the investigators observed in this extracted-tooth setting. It does not provide the numerical results or methodological detail needed to judge the size and precision of the primary comparison. The findings are also limited to the tissue examination described in the registry; they do not establish effects on clinical outcomes.
9. Statistical Methods Explained
The registry identifies the primary measure as a mean of a continuous measure, with standard deviation as the dispersion summary. Although the underlying observation is a cell count, the registered summary parameter is the mean. A mean describes the average observed count in the analyzed tissue samples. A standard deviation describes the spread of observations around that average. Together, these summaries can show whether counts are generally low or high and whether they vary substantially across observations. In this record, the numerical mean and standard deviation are not reported in the registry record.
What does a confidence interval add?
General statistical context: a confidence interval expresses uncertainty around an estimate. It gives a range of values that are compatible with the data under the statistical method used. The estimate alone describes the observed contrast; the interval helps readers assess its precision. A narrow interval indicates greater precision than a wide interval, while an interval spanning a broad range leaves more uncertainty about the size and direction of the contrast. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be assessed from the posted results.
How should a test result be read?
General statistical context: a p-value, when reported, describes how unusual data at least as inconsistent with a specified null model would be, assuming that model and the analysis assumptions hold. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. A p-value should be interpreted alongside an effect estimate and its uncertainty. The registry record does not report a p-value or a statistical test for the primary endpoint. The qualitative summary of “no difference” should therefore not be treated as a reported test result.
Why do the design details matter?
General statistical context: random allocation can help balance measured and unmeasured characteristics between comparison groups, on average. When allocation is not randomized, differences between groups may reflect their selection or other features as well as the intervention. Here, the registry lists allocation as NA and identifies a single-group model, while also describing treated and control teeth. It explicitly warns that the arms are not a like-for-like control comparison. Since the record does not report a method for addressing group differences, the design limits causal interpretation of any observed contrast.
The measurement also has a nested structure in principle: cell counts are observed in tissue cross-sections, and teeth are associated with study participants. General statistical context: observations from the same person or specimen may be related, so treating every observation as independent can make uncertainty estimates misleading. The registry record does not report the number of samples or sections contributing to the analysis, whether multiple measurements came from a tooth, or whether the analysis accounted for any clustering. It is therefore not possible to assess this issue from the posted information.
What can be inferred from planning illustrations?
The registry record does not report the trial's own sample-size justification. Any planning illustrations accompanying the posted analysis are not the study's observed power and should not be read as a retrospective test of whether the study succeeded. The stated illustration assumptions use a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is defined as a stated fraction of the observed effect. Those assumptions describe a planning exercise, not necessarily the study's actual design or analysis. The registry's allocation field is NA, and the study is described as a single-group model, so equal allocation in a planning illustration should not be mistaken for the actual allocation process. Numerical primary outcome estimates are not reported in the registry record, which further limits interpretation of any effect-based planning scenario.
General statistical context: cell counts can have distributions that differ from the symmetric distributions often assumed by simple methods, especially when counts are uneven or highly variable. Over-dispersion means that variability is greater than a model expects; if ignored, standard errors and uncertainty intervals may be too small. A count-based model may be considered in some settings, but the appropriate approach depends on the data structure and assumptions. The registry record does not report the distribution of cell counts, a model specification, or diagnostic checks. No particular analysis method can therefore be attributed to this study.
The record lists no analyses. That absence, together with the lack of numerical results, prevents reconstruction of the primary comparison or independent checking of its statistical uncertainty. The general concepts above explain how such an analysis might be evaluated; they are not a description of an analysis confirmed by the registry.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures and identifies the cell count of inflammatory infiltrate as the primary outcome. A secondary outcome is the gap distance of inflammatory resorption between cementum and alveolar bone. The registry record does not describe the remaining outcome measures in the information available for this analysis. It lists no analyses, so it is not possible to determine which outcomes were analyzed, how many comparisons were made, or whether any outcomes were omitted from the posted results.
When a study assesses multiple outcomes or makes multiple statistical comparisons, the chance of at least one apparently notable result can increase. General statistical context: multiplicity procedures can address this issue, but their appropriateness depends on which outcomes and comparisons were planned and which claims are intended to be confirmatory. The registry record does not report a multiplicity strategy or identify a hierarchy of analyses beyond naming the primary outcome. It is therefore not possible to assess how multiplicity was handled.
Missing-data handling is also not reported in the registry record. There is no description of whether observations were unavailable, why they might be missing, or how missing outcome values were treated. The number of teeth contributing to the primary endpoint analysis and the analysis population are not reported in the registry record. No intention-to-treat, per-protocol, or other analysis population is specified. These omissions make it difficult to judge whether the reported qualitative summary represents all enrolled teeth or a subset, and whether the analyzed observations correspond to the intended study population.
These uncertainties matter because outcome selection, missing observations, and analysis-population decisions can affect how a result should be interpreted. The record does not provide enough detail to resolve them.
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 |
|---|---|---|---|
| Teeth Exposed to Laser and ICG Solution. | 0 | 10 | 0.0% |
| Control Teeth Not Exposed to Laser and ICG Solution. | 0 | 2 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Teeth Exposed to Laser and ICG Solution. | 0 of 12 |
| Control Teeth Not Exposed to Laser and ICG Solution. | 0 of 2 |
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 |
|---|---|
| Teeth Exposed to Laser and ICG Solution. | 0 of 10 |
| Control Teeth Not Exposed to Laser and ICG Solution. | 0 of 2 |
The registry lists adverse events separately for teeth exposed to laser and ICG solution and control teeth not exposed to laser and ICG solution. For the exposed group, 10 are listed at risk for serious adverse events and 10 at risk for other adverse events; the listed counts affected are zero for both categories, and deaths are zero. For the control group, 2 are listed at risk for serious adverse events and 2 at risk for other adverse events; the listed counts affected are zero for both categories, and deaths are zero.
These are descriptive counts from the adverse-event listing. They do not provide a statistical comparison, and the registry does not list serious adverse-event terms. The at-risk counts should not be assumed to be the numbers contributing to the primary histological analysis; the record does not report that connection. The different listed at-risk counts also reinforce why the groups should not be treated as a balanced, randomized comparison.
General statistical context: observing no events in a group does not by itself establish that the underlying event risk is zero. With limited observations, uncommon events may not appear in the observed data. The registry provides no event-rate estimate or uncertainty interval, so the adverse-event counts should be read as the events listed for this record, not as proof that no risk exists.
12. What the Result Does, and Does Not, Mean
The record's main qualitative statement is that histological and morphological examination of cementum, ligament, and collagen after exposure showed no difference in those structures compared with non-treated controls. This statement describes the reported tissue observations. It does not supply numerical results for the primary cell-count endpoint, and it does not establish that the treatment and control conditions were equivalent.
The primary endpoint is a tissue-level measure of inflammatory infiltrate in a defined cross-sectional area at 400X magnification, assessed 28 days after intervention. Numerical means, standard deviations, group sizes for that outcome, and an estimate of the between-group contrast are not reported in the registry record. Consequently, the direction, magnitude, and precision of the primary endpoint comparison cannot be independently evaluated from the posted results. The qualitative summary should not be expanded into a claim about a particular cell-count difference or the absence of a meaningful difference.
The study was conducted in extracted mandibular incisors scheduled for extraction for other reasons. Its results therefore concern the histological examination described in the record. They do not establish what would happen in other teeth, in other settings, or for clinical outcomes not measured in this record. The comparison is also nonrandomized according to the registry, which limits the ability to attribute any observed difference or similarity specifically to laser and ICG exposure.
General statistical context: absence of a statistically significant result, if one had been reported, would not alone prove equivalence; an equivalence conclusion requires a suitable design and a prespecified margin, among other details. The registry does not report such a margin or an equivalence analysis. The most defensible reading is therefore limited: the brief summary reports no difference in the examined structures, while the numerical primary endpoint results and the precision of the comparison remain unavailable in the registry record.
13. Why This Trial Matters Statistically
This study illustrates why design labels and comparison details both matter. The registry classifies the model as single group and allocation as NA, yet it also describes exposed teeth and control teeth. It explicitly warns that the comparison is not randomized and that the arms are not a like-for-like control comparison. Readers should retain both pieces of information rather than interpreting the control description as evidence of a balanced trial design.
The record also demonstrates the distinction between a qualitative conclusion and a quantitatively interpretable result. Its brief summary says that histological and morphological examination showed no difference in specified structures, but numerical results for the primary inflammatory-cell count are not reported. Without an estimate and its uncertainty, the size and precision of the comparison cannot be judged. A concise statement of no difference does not substitute for those statistics.
General statistical context: transparent reporting of group sizes, outcome summaries, uncertainty, analysis methods, and missing-data handling lets readers assess how results were obtained and how much confidence to place in a comparison. Their absence does not prove that no analysis was conducted, but it limits what can be evaluated from the registry. The record lists 4 outcome measures and no analyses, and it does not report a trial-specific sample-size justification.
The adverse-event listing supplies counts for exposed and control teeth, but those counts should be kept distinct from the primary endpoint and from questions of tissue response. The study is statistically instructive because it requires careful separation of design, measurement, qualitative findings, safety listings, and unreported quantitative results. That separation prevents a narrow histological observation from being overstated as a broader conclusion.
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 most immediate limitation is that numerical results for the primary endpoint are not reported in the registry record. The mean, standard deviation, group sizes contributing to the endpoint, comparison estimate, and precision measure are unavailable. The qualitative summary of no difference in examined structures cannot replace those data.
The registry identifies a single-group model, allocation as NA, and masking as NONE. It also cautions that the exposed and control arms are not a like-for-like control comparison. The record does not report a method for accounting for differences between these groups, so causal interpretation is limited. Enrollment is listed as 10, but the number of teeth or tissue samples included in each outcome analysis is not reported in the registry record.
The primary outcome was assessed 28 days after intervention. This registry entry therefore does not establish longer-term tissue findings. The study population is described as mandibular incisor teeth requiring extraction for other reasons, which limits how broadly its histological observations can be applied. The registry does not report whether multiple tissue sections or observations from the same tooth or participant were analyzed together.
Important statistical details are also unavailable: the analysis method, handling of missing observations, analysis population, multiplicity approach, and sample-size justification are not reported in the registry record. The adverse-event listing has different at-risk counts for exposed and control groups and should not be taken as evidence of balanced comparison or as a denominator for the primary endpoint. These limitations make the record useful as a description of the study question and qualitative finding, but insufficient for a detailed assessment of the primary effect's magnitude and precision.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Histopathological Evaluation of the Periodontal Ligament Subjected to Laser Ablation. — NCT06173648.
- Registry record last updated 2024-02-29; status last verified 2024-02.
- Results first posted 2024-02-29.
- 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.
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18. Record Summary
The registry record describes a completed study of laser ablation with ICG in extracted mandibular incisors. The intervention used an 810nm diode laser and ICG solution. Enrollment is listed as 10; the study model is single group, allocation is NA, and masking is NONE. The primary outcome was inflammatory infiltrate cell count per cross-sectional area at 400X magnification, measured 28 days after intervention.
The brief summary reports no difference in histological and morphological examination of cementum, ligament, and collagen compared with non-treated controls. Numerical results for the primary endpoint, confidence intervals, p-values, and a detailed analysis method are not reported in the registry record. The registry cautions that the exposed and control arms are not a like-for-like randomized comparison. Its adverse-event listing reports zero serious events, zero other events, and zero deaths in both listed groups.