Effect of Different Cavity Designs on the Clinical Performance of 3D- Printed Resin Composite Partial-Coverage Restorations in Vital Molars

June 19, 2026 updated by: Lilly Assem Mousa Ahmed, Cairo University

Effect of Different Cavity Designs on the Clinical Performance of 3D- Printed Resin Composite Partial-Coverage Restorations in Vital Molars With Complex Cavities: An 18 Month Randomized Clinical Trial

This randomized clinical trial aims to evaluate the effect of different cavity designs on the clinical performance of 3D-printed resin composite partial-coverage restorations in vital molars with complex cavities over an 18-month follow-up period.

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

Despite these material advancements, growing evidence indicates that cavity preparation design exerts a greater influence on the clinical performance of indirect restorations than material selection alone. However, current evidence regarding preparation design is predominantly derived from in vitro studies and remains inadequately validated under clinical conditions, particularly in vital molars. Although recent randomized clinical trials have begun to address this gap, available data remain limited and largely confined to endodontically treated teeth. Therefore, a rigorously designed randomized clinical trial is warranted to evaluate the influence of different cavity preparation designs on the clinical performance of indirect restorations in vital molars.

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

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adult patients aging 20-45 years.
  2. Healthy males and females
  3. Patients with good oral hygiene
  4. Patients presenting with at least one eligible permanent molar requiring a partial-coverage restoration.
  5. Patients willing and able to attend scheduled follow-up visits for 18 months.
  6. Permanent maxillary or mandibular molars.
  7. Vital teeth with a positive response to cold thermal testing.
  8. Complex Large or severely compromised cavities resulting from primary or secondary caries (ICDAS 5 or 6) and/or replacement of large defective restorations with at least 2 missing cavity walls requiring overlay restorations
  9. Well-formed and fully erupted in normal functional occlusion with natural antagonist and adjacent teeth.
  10. Absence of any radiographic, periodontal or periapical changes.

Exclusion Criteria:

  1. Participants with general/systemic illness.
  2. Pregnant or lactating females.
  3. Concomitant participation in another research study.
  4. Inability or unwillingness to comply with study visits and procedures.
  5. Heavy bruxism or other parafunctional habits
  6. Known allergic reactions against any components of the used materials
  7. Patients receiving orthodontic treatment.
  8. Poor oral hygiene or high caries activity.
  9. Non vital teeth.
  10. Hypersensitive teeth.
  11. Teeth with prior endodontic treatment.
  12. Teeth with spontaneous pain or signs/symptoms of irreversible pulpitis.
  13. Teeth with advanced periodontal disease or mobility.
  14. Teeth with a history of direct or indirect pulp capping procedure.
  15. Teeth with vertical root fractures or cracked tooth syndrome

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: Triple

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: Anatomical cavity design preparation
Following caries excavation and removal of defective restorations, cavity preparations will be carried out according to the accepted principles of adhesive overlays. The cavity walls will be prepared with 6-12° internal axial wall divergence using blue-coded tapered round-end diamond burs (Komet, USA) and subsequently finished using extra-fine yellow-coded tapered round-end diamond burs (#368EF, Komet, USA). The thickness of potentially maintainable cusps will be assessed using a dental caliper (Diamonds Surgical Instruments, Pakistan). Weakened or undermined cusps (less than 2 mm thickness) will be reduced using the same diamond burs to create an anatomical occlusal reduction following the natural tooth morphology, with a reduction of 2 mm.
Procedure: Anatomical cavity design preparation
Cavity preparation design for adhesive restoration
Active Comparator: Butt joint cavity design preparation
The cavity walls will be prepared with 6-12° internal axial wall divergence using blue-coded tapered round-end diamond burs (Komet, USA) and subsequently finished using extra-fine yellow-coded tapered round-end diamond burs (#368EF, Komet, USA). The thickness of potentially maintainable cusps will be assessed using a dental caliper (Diamonds Surgical Instruments, Pakistan). The occlusal reduction design, where weakened or undermined cusps will be reduced using a wheel stone (#909, Komet, USA) to create a flat butt-joint occlusal design with a uniform occlusal reduction of 2 mm. Additional reduction will be performed when necessary, and the available interocclusal clearance will be verified using a graduated periodontal probe in maximum intercuspation and eccentric movements.
Procedure: Butt joint cavity design preparation
Cavity preparation design for adhesive restoration

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
Fracture
Time Frame: 18 Months
Modified USPHS Ryge Criteria (Ordinal scoring system)
18 Months

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
Retention, marginal integrity, marginal discoloration, wear/anatomic form, secondary caries and surface texture
Time Frame: 18 Months
Modified USPHS Ryge Criteria (Ordinal scoring system)
18 Months

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.
July 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.
January 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.
January 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).
June 19, 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.
June 19, 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.
June 25, 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.
June 25, 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.
June 19, 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.
June 1, 2026

More Information

Terms related to this study

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.
  • Effect of Cavity Designs

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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