Clinical Performance and Fit of 3D-Printed Versus Milled Endocrowns: An 18-Month Trial

Summary

The goal of this clinical trial is to learn whether 3D-printed resin composite endocrowns perform as well as milled resin composite endocrowns in restoring endodontically treated teeth. It will also learn how well the restorations fit over time.

The main questions it aims to answer are:

Do 3D-printed endocrowns and milled endocrowns show different clinical performance? Do 3D-printed endocrowns and milled endocrowns differ in restoration fit over 18 months?

Researchers will compare two fabrication methods:

Additive manufacturing: 3D-printed resin composite endocrowns. Subtractive manufacturing: milled resin composite endocrowns.

Participants will:

Be recruited from the Conservative Dentistry Department, Faculty of Dentistry, October 6 University.

Receive tooth preparation after confirmation of satisfactory root canal treatment.

Have their teeth prepared using standardized endocrown guidelines by one calibrated operator.

Have digital scans taken of the prepared tooth, opposing arch, and bite registration.

Have restorations designed digitally and then assigned randomly to one of the two groups.

Receive a temporary restoration until the final endocrown is ready.

Have the final restoration tried in for fit, contacts, and occlusion before cementation.

Have a baseline post-cementation scan taken for fit assessment.

Return for follow-up visits at baseline, 6 months, 12 months, and 18 months.

Be evaluated at each visit using Modified FDI criteria and 3D digital superimposition for fit analysis.

Conditions

• Clinical Performance of Endodontically Treated Teeth Restored With Endocrowns
• Restoration Fit of Endodontically Treated Teeth With Endocrowns

Interventions

OTHER

Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.

Subtractive Manufacturing, the control group will utilize restorations fabricated via subtractive manufacturing, specifically by milling from industrially fabricated blocks of nanohybrid composite. This method is the established gold standard for producing CAD/CAM resin composite restorations. It is known for creating restorations with excellent mechanical properties, high density, and predictable clinical performance due to the optimized, industrial-grade polymerization of the blocks. These materials, which include polymer-infiltrated ceramic networks (PICNs) and resin nanoceramics, were developed to combine the favorable properties of both ceramics and resin composites, offering a biomimetic alternative to traditional glass-ceramics.

OTHER

Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturing

Additive Manufacturing, the intervention group will feature restorations fabricated via 3D printing. This technology is more time and cost-efficient, more accurate, and could provide a considerable alternative to the currently applied CNC milling, reduced material waste, and the ability to create complex geometries with high precision. Recent studies have shown that 3D-printed restorations can achieve promising results in terms of marginal and internal fit, which are critical for clinical longevity. This has spurred the development of novel, ceramic-filled hybrid materials specifically engineered for permanent 3D-printed restorations. Manufacturers of these materials claim high dimensional stability, flexural strength, and a modulus suitable for definitive restorations (e.g., Bego; VarseoSmile Triniq technical product data sheet). However, there is a lack of clinical data to support these claims.

Sponsors & Collaborators

• October 6 University

  lead OTHER

Principal Investigators

• Mohsen Hussein Abielhassan, • Professor, Conservative Dent · October 6 University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-11-01

Primary Completion

2028-11-01

Completion

2028-12-01

Countries

• Egypt

Study Locations