The Effect of Decoupling With Time Technique on the Clinical Performance of Proximal Posterior Composite Restorations (DWT)

October 30, 2026 updated by: Mahetab Mahmoud, Cairo University

The Effect of Decoupling With Time Technique on the Clinical Performance of Proximal Posterior Composite Restorations: An 18-Month Randomized Clinical Trial

This randomized clinical trial will evaluate whether the decoupling with time technique improves the clinical performance of Class II posterior composite restorations compared with conventional composite restoration techniques. The study will also assess postoperative hypersensitivity and the additional operative time required to perform the decoupling with time technique. Participants will receive a posterior composite restoration and will be followed for 18 months. Clinical performance will be evaluated using the Modified United States Public Health Service (USPHS) criteria, and postoperative hypersensitivity will be assessed before treatment, 1 week after restoration placement, and at 6, 12, and 18 months. The study will help determine whether the additional time required for the decoupling with time technique is associated with improved clinical outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This randomized clinical trial will evaluate the effect of the decoupling with time technique on the clinical performance of posterior composite restorations in Class II cavities.

The study will include eligible participants requiring posterior Class II composite restorations. Participants will be randomly allocated to either the decoupling with time group or the conventional restoration group.

In the decoupling with time group, following cavity preparation, immediate dentin sealing will be performed using a universal adhesive system applied with a selective enamel-etching strategy. A conventional flowable resin composite will then be applied as an initial stress-reducing layer with a thickness of approximately 0.5-1.0 mm. A 5-minute waiting period will be allowed before completion of the composite restoration. Deep margin elevation will not be performed as part of the study protocol.

The control group will receive a conventional posterior composite restoration according to the standardized restorative protocol without the decoupling with time waiting period.

The primary outcome will be postoperative hypersensitivity, assessed using the Modified United States Public Health Service (USPHS) criteria. Hypersensitivity will be assessed pre-operatively, at 1 week after restoration placement, and at 6, 12, and 18 months after restoration placement.

The clinical performance of the restorations will be evaluated using the Modified USPHS criteria immediately after restoration placement and at 6, 12, and 18 months. The evaluated clinical parameters will include marginal integrity, fracture and retention, marginal discoloration, anatomic form, proximal contact, surface texture, radiographic evaluation, and secondary caries.

The total operative time required to complete each restoration will also be recorded in minutes using a digital stopwatch, starting from the beginning of the restorative procedure and ending upon completion of the restoration. This will allow assessment of whether the additional operative time associated with the decoupling with time technique is associated with improved clinical outcomes.

Participants will be followed for 18 months to evaluate the clinical performance of the restorations and postoperative hypersensitivity over time.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 40 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients aged between 20 and 40 years.
  • Patients with posterior carious Class II lesions.
  • Good oral hygiene.
  • Favorable occlusion.
  • Absence of deleterious oral habits.

Exclusion Criteria:

  • Teeth showing signs of irreversible pulpitis.
  • Teeth with secondary caries.
  • Teeth with old restorations.
  • Endodontically treated teeth.
  • Patients with a history of adverse reactions to the test material.
  • Patients with poor oral hygiene.
  • Patients with systemic disease.
  • Patients with severe periodontal disease.
  • Uncooperative patients.
  • Patients unable to attend the scheduled recall visits.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Decoupling With Time Group

Participants assigned to this group will receive a Class II posterior composite restoration using the decoupling with time technique. Immediate dentin sealing will be performed using a universal adhesive system with a selective enamel-etching strategy, followed by application of a 0.5-1.0 mm layer of conventional flowable resin composite. A 5-minute waiting period will be allowed before completion of the composite restoration.
Procedure: Decoupling With Time Technique

Immediate dentin sealing using a universal adhesive system with a selective enamel-etching strategy, followed by application of a 0.5-1.0 mm layer of conventional flowable resin composite and a 5-minute waiting period before completion of the posterior composite restoration.
Active Comparator: Conventional Composite Group

Participants assigned to this group will receive a conventional Class II posterior composite restoration without the decoupling with time procedure or the additional 5-minute waiting period.
Procedure: Conventional Composite Restoration

Conventional Class II posterior composite restoration without the decoupling with time procedure.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Postoperative Hypersensitivity
Time Frame: Pre-operatively, 1 week, 6 months, 12 months, and 18 months after restoration placement.

Postoperative hypersensitivity will be assessed clinically using the Modified United States Public Health Service (USPHS) criteria. The assessment will be performed before the restorative procedure and at the specified follow-up visits after restoration placement.
Pre-operatively, 1 week, 6 months, 12 months, and 18 months after restoration placement.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Clinical Performance of Posterior Composite Restorations
Time Frame: Immediately after restoration placement, 6 months, 12 months, and 18 months after restoration placement.

Clinical performance of the restorations will be evaluated using the Modified United States Public Health Service (USPHS) criteria. The evaluated parameters will include marginal integrity, fracture and retention, marginal discoloration, anatomic form, proximal contact, surface texture, radiographic evaluation, and secondary caries.
Immediately after restoration placement, 6 months, 12 months, and 18 months after restoration placement.
Total Operative Time
Time Frame: During the restorative procedure.

The total time required to complete each restorative procedure will be measured in minutes using a digital stopwatch, starting from the beginning of the restorative procedure and ending upon completion of the restoration.
During the restorative procedure.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cairo University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 30, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 30, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 4, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 30, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Cons-DWT-C.Perf-2026

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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