Additive vs Subtractive Manufacturing for Endocrown Fabrication: A 24-Month RCT (ENDO-3D)

June 4, 2026 updated by: Dina Ezz, Cairo University

Additive Versus Subtractive Manufacturing for Endocrown Fabrication: A Clinical Comparison of 3D-Printed Ceramic-Filled Photopolymer Resin and CAD/CAM Milled Resin Nano-Ceramics Endocrowns in Posterior Teeth - A 24-Month Randomized Controlled Trial

This randomized controlled trial (RCT) compares the 24-month clinical performance of endocrown restorations fabricated by two digital manufacturing pathways: additive manufacturing using 3D-printed ceramic-filled photopolymer resin (VarseoSmile TriniQ, BEGO) versus subtractive computer-aided design/computer-aided manufacturing (CAD/CAM) milling from hybrid nano-ceramic blocks (HC Hard Block, Shofu). Sixty endocrowns will be placed in endodontically treated posterior molars and evaluated using modified United States Public Health Service (USPHS) criteria at 6, 12, and 24 months. The trial is conducted at the Conservative Dentistry Department, Faculty of Dentistry, Cairo University.

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

Post-endodontic rehabilitation of extensively damaged posterior molars using endocrowns represents a minimally invasive alternative to conventional crown-plus-post-and-core approaches. Digital fabrication has advanced both the precision and reproducibility of endocrown manufacture. While computer-aided design/computer-aided manufacturing (CAD/CAM) milled hybrid ceramic endocrowns are well-validated clinically, prospective clinical data comparing 3D-printed definitive restorations to milled counterparts are absent. This trial employs a parallel-group, 1:1 randomized design with triple blinding of participants, outcome assessors, and statistician. All restorations are delivered using Beautilink SA self-adhesive dual-cure resin cement. The primary outcome is fracture resistance at 24 months; secondary outcomes include retention, marginal adaptation, marginal discoloration, surface texture, anatomic form, color match, secondary caries, fabrication time, and patient satisfaction assessed by Visual Analogue Scale (VAS).

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.
60

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 25-45 years, male or female
  • Endodontically treated molar tooth with radiographically confirmed treatment success and no clinical signs of failure
  • Sufficient remaining coronal structure for endocrown preparation: minimum three walls, wall thickness 1.5 mm or greater, pulp chamber depth 3 mm or greater, supragingival preparation margins
  • Completely erupted tooth with intact periodontal support
  • Minimum of 20 occluding teeth
  • Satisfactory oral hygiene status
  • Capable of providing written informed consent and committed to scheduled follow-up visits

Exclusion Criteria:

  • Diagnosed parafunctional habit or nocturnal bruxism
  • Uncontrolled systemic illness or physical disability precluding safe participation
  • Heavy tobacco use
  • Current or suspected pregnancy
  • Periapical disease or radiographic signs of endodontic failure
  • Evidence of pathological tooth wear or occlusal erosion
  • Moderate-to-severe periodontitis or tooth with hopeless prognosis
  • Radiographic or clinical evidence of vertical root fracture
  • Impaired decision-making capacity or anticipated non-compliance

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: Double

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.
Active Comparator: CAD/CAM Milled Endocrown
Endocrown restoration fabricated by subtractive CAD/CAM milling from HC Hard Block hybrid nano-ceramic (Shofu Inc., Japan), designed using ExoCAD software and milled on a five-axis wet-milling unit. Adhesively cemented using Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
Device: CAD/CAM Milled HC Hard Block Endocrown
Endocrown restoration milled from HC Hard Block hybrid nano-ceramic (Shofu Inc., Japan) using a five-axis wet-milling CAD/CAM unit. Restoration designed with ExoCAD software, finished and glazed per manufacturer protocol, and cemented with Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
Other Names:
  • CAD/CAM Milled Endocrown
Experimental: 3D-Printed Endocrown
Endocrown restoration fabricated by additive manufacturing using VarseoSmile TriniQ ceramic-filled photopolymer resin (BEGO GmbH & Co. KG, Germany), printed on a 4K LCD printer at 30-45 degree build angle, post-cured under nitrogen atmosphere. Adhesively cemented using Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
Device: 3D-Printed VarseoSmile TriniQ Endocrown
Endocrown restoration 3D-printed using VarseoSmile TriniQ ceramic-filled photopolymer resin (BEGO GmbH & Co. KG, Germany) on a 4K LCD printer at 30-45 degree build angle. Post-cured under nitrogen atmosphere, surface glazed, and cemented with Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
Other Names:
  • 3D-Printed Endocrown

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
Restoration Fracture Resistance
Time Frame: 24 months
Assessed using modified USPHS criteria: Alpha = absence of fracture; Bravo = minor chip amenable to repair; Charlie = catastrophic fracture, unrestorable
24 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
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = in situ; Bravo = partial displacement; Charlie = complete loss
6, 12, and 24 months
Marginal Discoloration
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = absent; Bravo = superficial; Charlie = penetrating
6, 12, and 24 months
Surface Texture
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = smooth; Bravo = minor irregularities; Charlie = extensive breakdown
6, 12, and 24 months
Anatomic Form
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = conforms to natural contour; Bravo = discrepancy present, dentin intact; Charlie = dentin or base exposed
6, 12, and 24 months
Color Match
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = indistinguishable from adjacent tooth; Bravo = minor deviation, clinically acceptable; Charlie = obvious mismatch; Delta = gross color failure
6, 12, and 24 months
Secondary Caries
Time Frame: 6, 12, and 24 months
Modified USPHS: Alpha = absent; Charlie = present
6, 12, and 24 months
Fabrication Time
Time Frame: Periprocedural
Time in minutes from CAD design completion to restoration readiness for cementation
Periprocedural
Patient Satisfaction
Time Frame: 6, 12, and 24 months
Visual Analogue Scale 0-100 mm; 0 = entirely dissatisfied, 100 = entirely satisfied
6, 12, and 24 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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • Abou-Steit S, Ibrahim SH, Salem M. Three years clinical evaluation of lithium disilicate and hybrid nano-ceramic CAD/CAM endocrowns (randomized clinical trial). Egyptian Dental Journal 2024;70:551-561.

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.
June 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.
June 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.
September 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).
May 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.
June 4, 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 8, 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 8, 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 4, 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

Additional Relevant MeSH Terms

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.
  • /4/26 3D-Printed vs CAD/CAM

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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