Fissure Caries Inhibition Study With Solea CO2-9.3μm Short-pulsed Laser: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Fissure Caries Inhibition Study With Solea CO2-9.3μm Short-pulsed Laser (NCT02357979), a randomized na study. The primary outcome is International Caries Detection and Assessment System (ICDAS II) - Number of Molars With ICDAS Score of 3 or More - ICDAS Score 3, Cavity -.

2. Clinical Question

The question is about the additional contribution of laser treatment when both sides receive fluoride varnish. It is not a comparison of laser treatment alone with no treatment. The within-mouth comparison is intended to account for characteristics shared by the two teeth in the same participant. Whether the reported results preserve that matched comparison in the analysis is not clear from the registry record: it reports arm-level counts but no analysis. The record also does not report details of the randomization procedure, the masking procedure, or the exact criteria for inclusion. Consequently, the clinical question can be described from the registered objective and treatment descriptions, but the posted information does not establish how every design feature was implemented.

3. Trial Design

The registry describes a randomized, single-blind, prospective, split-mouth controlled clinical trial with a stated duration of 12 months. The study is listed as completed, with enrollment of 60. Its start date is 2018-02-08 and its primary completion date is 2020-01-31. The sponsor is University of California, San Francisco. The phase is listed as not applicable.

In the registered split-mouth description, a molar on one side of the mouth received laser treatment plus fluoride varnish, and the contralateral tooth in the same jaw received fluoride varnish alone. The latter served as the control. This structure gives each participant teeth assigned to both treatment conditions, so the observations are naturally matched within a participant. The record identifies randomization, but does not report which aspect was randomized, how the sequence was generated, or how allocation was concealed.

There is a design-label ambiguity: the trial description and arm descriptions identify a split-mouth comparison, while the registry’s model classification is parallel. Those descriptions do not by themselves establish the analytic structure used for the posted outcome. The masking entry says single, but who was masked and how masking was maintained are not reported in the registry record.

The primary outcome is a count of molars with an ICDAS score of 3 or more, with a stated timeframe of 1 year. The registry’s outcome description refers to changes from baseline to 6 months and from baseline to 12 months. It also lists Change in SOPROlife Scores as a secondary outcome. Although the registry lists 3 outcome measures, the available record does not give full descriptions for all of them. It does not report the protocol’s sample-size justification, planned interim analyses, or a detailed statistical analysis plan.

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.

Population: Each participant had to provide a cavity free pair of second molars (right and left second molar in one jaw (upper or lower jaw) - only ICDAS scores 0, 1 and 2 were allowed at baseline for these teeth.

6. Primary Endpoint

The registry lists the primary outcome as International Caries Detection and Assessment System (ICDAS II) - Number of Molars With ICDAS Score of 3 or More - ICDAS Score 3, Cavity -, measured over 1 year.

The primary endpoint is the number of molars with an International Caries Detection and Assessment System (ICDAS II) score of 3 or more. The unit is a right or left second molar, and the registry gives a timeframe of 1 year. ICDAS is a visual assessment of caries. Its scores range from 0, meaning no demineralization, to 6, meaning a huge cavity. A score of 3 signifies a first physical loss of enamel and is described in the outcome title as a cavity.

The endpoint is intended to capture whether lesions change to the specified threshold over follow-up. The registry’s outcome description says the comparison concerns differences in lesion changes between matched case and control teeth from baseline to 6 months and from baseline to 12 months. This threshold-based count is clinically interpretable as a tally of molars reaching a defined level of visual caries severity, rather than a continuous measurement of lesion size.

The posted primary outcome gives arm-level values of 0 for Laser & Fluoride and 13 for Fluoride Alone, with 55 in each arm. The record does not post baseline and follow-up values separately, nor does it provide a paired analysis of the stated changes. Therefore, the counts alone do not show how many individual matched teeth changed from baseline, or how the changes were distributed within participants. The registry record does not report additional endpoint validation or adjudication details.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

How should a split-mouth comparison be understood?

In general, a split-mouth design assigns treatment conditions to different sides or teeth in the same participant. The registered description identifies one treated molar and its contralateral control tooth in the same jaw. Because both teeth come from the same person, their results may be related. A statistical analysis can account for this relationship by comparing matched observations rather than treating every tooth as unrelated to every other tooth. This can be important for estimating uncertainty as well as the treatment contrast.

The registry says the trial was randomized, but does not report the randomization procedure or the unit randomized. It also labels the model parallel, despite describing a split-mouth design. These details leave uncertainty about the exact planned and implemented analysis structure. The posted arm counts do not identify which outcomes belong to matched pairs, and the record reports no analysis that resolves this issue.

What does an endpoint count convey?

In general, a count records how many units meet a defined condition. Here, the condition is an ICDAS II score of 3 or more, and the unit is a right or left second molar. Counts are not the same as a measure of how severe every lesion is: a molar below the threshold and a molar with a much higher score both fall outside or inside the count according to the threshold. The endpoint description makes score 3 the threshold of interest because it represents first physical loss of enamel.

Count data can be analyzed with methods suited to counts and, when relevant, with methods that recognize matching or repeated observations. In general, over-dispersion occurs when count variability exceeds what a simple count model assumes; accounting for it can affect uncertainty estimates. The registry does not report a model, an over-dispersion assessment, or another statistical method for this outcome. This is a general methodological consideration, not a description of an analysis used in this trial.

Why is the paired structure relevant to precision?

In general, confidence intervals describe a range of estimates compatible with the data and the statistical model, and their width reflects precision. For matched observations, uncertainty depends not only on the arm totals but also on how outcomes co-occur within pairs. The two reported counts, 0 and 13, do not contain the pair-level information required to reconstruct that relationship. No confidence interval is posted, so the precision of the trial’s primary comparison cannot be evaluated from the registry counts alone.

Randomization can support a fair comparison when it is carried out as planned, but the word “randomized” does not itself describe the sequence generation, concealment, implementation, or analysis. Those details are not reported in the registry record. Single masking is recorded, but the identity of the masked party and the success of masking are also not reported.

What can be said about the registered analysis?

The record lists no analyses for the primary outcome. It posts endpoint values by arm, but gives no inferential result, adjustment, model specification, or treatment-effect estimate. The outcome description calls for comparison of lesion changes at baseline-to-6-month and baseline-to-12-month intervals; the posted arm values do not provide a separate analysis for those intervals. It is not appropriate to infer a p-value or uncertainty range from the arm counts alone, particularly when the matched data are unavailable.

The registry includes planning notes describing an illustration based on the observed effect, a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The notes say the effect to detect is a stated fraction of the observed effect, and distinguish total events for time-to-event outcomes from participants per arm for other outcomes. These are planning assumptions, not a report of the trial’s original design or a measure of observed power. The registry record does not report the trial’s own sample-size justification or provide planning illustration values for this endpoint. Planning calculations cannot replace an analysis of the observed data.

In general, a complete interpretation of a clinical trial endpoint needs the outcome definition, analysis population, treatment contrast, method for handling the design, and an estimate of uncertainty. The registry supplies an endpoint definition and arm-level counts, but does not report the analysis needed to connect those counts to a precise treatment-effect estimate. The appropriate statistical reading is therefore descriptive and limited to the entries actually posted.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 3 outcome measures and names Change in SOPROlife Scores as a secondary outcome. The primary outcome description refers to lesion changes from baseline to 6 months and from baseline to 12 months. These multiple outcomes and time comparisons can raise multiplicity questions: in general, testing several outcomes or time points can increase the chance of at least one apparently notable result. A statistical plan may specify which comparisons are primary and how multiplicity is handled. The registry record does not report a multiplicity procedure, and the full descriptions of all outcome measures are not available.

The record lists no analyses. It therefore does not report a formal primary-outcome test or secondary-outcome results in the entries. No adjustment, hierarchy of tests, or prespecified selection among time points is described. The absence of a reported analysis does not establish that no analysis was conducted; it means the registry record does not provide one to assess.

The endpoint arm sizes are 55 and 55, while enrollment is 60. The registry does not explain this difference or report how missing observations were handled. It does not state whether the analysis used all randomized participants, only participants with observed outcomes, or another population. It also does not describe imputation, exclusions, or the handling of incomplete follow-up. The safety groups list 60 at risk in each arm, but those entries do not define the population used for the primary endpoint. In general, missing-data methods rely on assumptions about why observations are missing; those assumptions and methods are not reported in the registry record. Accordingly, the posted counts should not be interpreted as evidence about the handling or impact of missing 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 0% reporting threshold.

The adverse-event entries list 60 participants at risk in each group. For Laser & Fluoride, the record lists 0 serious adverse events, 0 other adverse events, and 0 deaths. For Fluoride Alone, it also lists 0 serious adverse events, 0 other adverse events, and 0 deaths. No top serious-event terms are listed.

These entries mean that the registry reports zero events in the categories recorded for the listed groups. They do not establish that no event of any kind occurred, because the record distinguishes serious from other adverse events and does not provide further event definitions, collection procedures, or narrative detail. The entries also do not indicate whether events were independently adjudicated or how long safety follow-up lasted; those details are not reported in the registry record.

The safety counts should be read separately from the primary endpoint counts. The record lists 60 at risk for safety in each group, while the primary endpoint arm sizes are 55 and 55. It does not explain the different counts. Zero posted events in these categories is a descriptive registry result, not a complete assessment of risk and not evidence that one treatment condition is safer than the other.

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

The posted result is a pair of descriptive arm-level counts for the primary ICDAS II endpoint: 0 molars in the Laser & Fluoride arm and 13 in the Fluoride Alone arm, with 55 in each arm. The endpoint is defined as the number of molars with an ICDAS score of 3 or more, with a stated timeframe of 1 year. These entries convey what the registry reports for the two arms, but they do not include an estimate of the matched treatment contrast or its uncertainty.

The result does not show how many participant-level pairs had a change in one direction, the other direction, or no change. Nor does it supply baseline counts or separate results for the stated baseline-to-6-month and baseline-to-12-month comparisons. Since the design description is split-mouth, this missing paired information matters for interpretation. The arm totals alone do not reveal how strongly the two teeth within a participant were related or how a paired analysis would characterize the data.

The counts also do not establish statistical significance, precision, or the likelihood that any difference would recur in another study. No p-value, confidence interval, or primary analysis is reported in the registry record. The posted information cannot determine whether the arm-size difference from reported enrollment reflects missing outcomes, a different analysis population, or another reason; that reason is not reported in the registry record.

More broadly, the record describes a study asking whether laser treatment adds to fluoride varnish in a split-mouth comparison. Its posted primary values are descriptive evidence from this registered trial, not a complete inferential result. They do not demonstrate that a treatment works or does not work, and they do not provide a basis for medical advice. Interpreting the comparison would require the matched outcome data, a clearly specified analysis, and information about follow-up and missing observations. Those items are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically interesting because its clinical question is framed as a within-participant comparison. Each participant’s treated side is compared with a contralateral control tooth in the same jaw. That design can reduce the influence of characteristics shared by teeth in the same person, but it also makes the paired structure central to the analysis. Arm-level counts without pair-level results do not show how the matched observations contribute to the comparison.

The registry’s description also illustrates why design labels and outcome definitions need to be read together. It describes a randomized, single-blind, prospective, split-mouth trial, while the model classification is parallel. The treatment descriptions clarify the intended within-mouth control, but the record does not explain the apparent classification difference or specify the statistical model. A study’s label alone is not enough to determine whether its reported analysis accounts for the design.

The endpoint uses a defined ICDAS threshold, which makes the outcome a count of molars reaching a specified score rather than a full description of every lesion’s score or course. The registry explains the score scale and the meaning of score 3, but the posted arm totals do not reveal changes at the stated time points or matched transitions. This distinction is important when judging what a count can and cannot communicate.

Finally, the record separates descriptive outcome values from statistical evidence. It reports arm counts but no analysis, effect estimate, or measure of precision. The example underscores that a result’s interpretation depends not only on the observed totals, but also on the design, analysis population, handling of missing observations, and uncertainty estimate. Those elements are not reported in the registry record, so the appropriate reading remains cautious and descriptive.

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 leaves important details about the primary comparison unspecified. Although the study is described as split-mouth, the model classification is parallel, and no analysis is posted to show how the matched teeth were handled. The record does not report which unit was randomized, the randomization procedure, allocation concealment, who was masked, or how masking was maintained. These omissions limit assessment of implementation and potential bias.

The primary endpoint is described as changes between baseline and follow-up, including baseline to 6 months and baseline to 12 months, but the posted outcome is a single set of arm-level counts with a timeframe of 1 year. Baseline values, separate time-point results, and paired transitions are not reported. No treatment-effect estimate, confidence interval, p-value, or statistical model is available. Thus, the magnitude and precision of the comparison cannot be assessed from the posted values.

Enrollment is 60, while each primary endpoint arm lists 55. The registry does not explain this difference or specify the analysis population, missing-data approach, exclusions, or completeness of follow-up. The safety record lists 60 at risk per group, but it does not resolve the primary-outcome population question. The record also lists 3 outcome measures but provides only one named secondary outcome, Change in SOPROlife Scores; fuller outcome descriptions and multiplicity procedures are not reported.

Finally, the registry does not report the protocol’s sample-size justification or detailed statistical analysis plan. The planning note describes an illustration based on the observed effect, but that does not establish the study’s original design assumptions. These limitations concern the information available in the registry record; they do not establish that the unreported procedures or analyses were not performed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Fissure Caries Inhibition Study With Solea CO2-9.3μm Short-pulsed Laser — NCT02357979.
• Registry record last updated 2021-01-28; status last verified 2021-01.
• Results first posted 2021-01-07.
• 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

NCT02357979 is a completed randomized, single-blind clinical trial sponsored by University of California, San Francisco. Enrollment was 60. The record gives a start date of 2018-02-08 and a primary completion date of 2020-01-31. Its title and treatment descriptions identify a prospective split-mouth comparison over 12 months, while the model classification is parallel.

The experimental condition was laser treatment plus fluoride varnish, compared with fluoride varnish alone on the contralateral tooth. The primary outcome is the count of molars with an ICDAS II score of 3 or more, with a timeframe of 1 year. The posted arm values are 0 and 13, with 55 in each arm. The registry also names Change in SOPROlife Scores as a secondary outcome.

No analysis is posted for the primary endpoint. The record does not report an effect estimate, uncertainty interval, missing-data method, or detailed statistical plan. Safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each group, with 60 at risk per group.