3-D Printed Resin Composite Versus Milled Resin Composite and Hybrid Ceramic Onlays: 2-Year Clinical Performance, Microtensile Bond Strength, Marginal and Internal Adaptation

NCT07633717 | Active Not Recruiting

• 1 other identifier: Sally Nagy Zaki 1993
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

Study Protocol Background The use of partial coverage restorations had increased significantly as a conservative alternative to full-coverage crowns, particularly in cases where the coronal tooth structure was extensively damaged and insufficient dentin remained to support direct restorations. These restorations were designed to preserve sound tooth structure while reinforcing weakened teeth affected by caries or fracture. Depending on the extent of cuspal coverage, partial coverage restorations were classified into inlays, onlays, and overlays. With the advancement of digital dentistry, computer-aided design and computer-aided manufacturing (CAD/CAM) technologies had become widely adopted, enabling the fabrication of restorations with improved precision, mechanical performance, and esthetics. Various restorative materials were introduced, including glass ceramics, polycrystalline ceramics, and resin-matrix ceramics (hybrid ceramics). Hybrid ceramics, such as Vita Enamic, combined a ceramic network reinforced by a polymer phase, providing enhanced mechanical properties and favorable clinical behavior. More recently, additive manufacturing technologies such as 3D printing had been introduced for the fabrication of definitive single-tooth restorations. However, limited evidence was available regarding their long-term performance, particularly in comparison with subtractive CAD/CAM materials. Additionally, marginal adaptation and bond strength were critical factors influencing clinical success, as failures were often initiated at the tooth-restoration interface. Therefore, this study was designed to evaluate and compare the clinical and laboratory performance of 3D printed restorations, milled CAD/CAM hybrid ceramics, and indirect resin composite onlays. \- Aim of the Study The study aimed to evaluate and compare the following:

1. 1.The 2-year clinical performance of 3D printed, milled CAD/CAM hybrid ceramic, and indirect resin composite onlays.
2. 2.The marginal and internal adaptation of the tested restorative materials.
3. 3.The micro-tensile bond strength to dentin. - Clinical Part Summary A randomized controlled clinical trial was conducted following CONSORT guidelines. Patients were selected from the outpatient clinic of the Faculty of Dentistry, Mansoura University. Inclusion criteria required the presence of at least three posterior teeth with weakened cusps indicated for indirect onlay or overlay restorations, good oral hygiene, and healthy vital teeth with no symptoms. Patients with severe bruxism, systemic instability, or allergies to study materials were excluded.

Conditions

Dental Caries

Keywords

CAD/CAM restorations; 3D printed restorations; hybrid ceramic; resin composite onlay; marginal adaptation; microtensile bond strength

Outcome Measures

Primary Outcomes (1)

• Marginal and Internal adaptation assessed by SEM.Micro-tensile bond strength (μTBS) in MPa.Clinical performance using modified FDI criteria.

  Marginal and Internal adaptation was evaluated using scanning electron microscopy (SEM) by measuring the marginal gap between the restoration and tooth structure at standardized time intervals. Assessments were performed at baseline, 6, 12, 18, and 24 months. Micro-tensile bond strength was measured in megapascals (MPa) using a universal testing machine after sectioning restored teeth into beams with approximately 1 mm² cross-sectional area. Specimens were subjected to tensile loading until failure. Clinical performance was evaluated using modified FDI criteria assessing aesthetic, functional, and biological properties of restorations. Evaluations were performed at baseline, 1, 6, 12, 18, and 24 months by calibrated examiners-

  1. Marginal Adaptation Time Frame: Baseline, 6 months, 12 months, 18 months, 24 months - 2. Micro-tensile Bond Strength Time Frame: Immediately after specimen preparation (in vitro) - 3. Clinical Performance (FDI Criteria) Time Frame: Baseline, 1 month,

Study Arms (1)

Clinical Evaluation of 3D-Printed Resin Composite, Milled Resin Composite, and Hybrid Ceramic Onlays

OTHER

This study aims to clinically evaluate and compare the performance of three restorative materials: 3D-printed resin composite, milled resin composite, and hybrid ceramic used for onlays. A within-subject crossover design will be applied, where each participant receives all three materials under controlled clinical conditions. Outcomes such as clinical performance, adaptation, and survival will be assessed and compared within the same patient over the follow-up period.

Device: 3D printed CAD/CAM hybrid resin onlay.Milled CAD/CAM hybrid ceramic onlay (Vita Enamic)Indirect resin composite onlay.

Interventions

3D printed CAD/CAM hybrid resin onlay.Milled CAD/CAM hybrid ceramic onlay (Vita Enamic)Indirect resin composite onlay. DEVICE

Indirect posterior onlays fabricated using 3D printed CAD/CAM hybrid resin material. The restorations were digitally designed, additively manufactured, and cemented using resin cement following standard adhesive protocols. Indirect posterior onlays fabricated using milled CAD/CAM hybrid ceramic material (Vita Enamic). Restorations were digitally designed, produced by subtractive milling, finished, and cemented using resin cement according to manufacturer instructions.Indirect posterior onlays fabricated using laboratory-processed resin composite material. The restorations were conventionally fabricated by a dental technician, surface-treated, and cemented using resin cement under standardized clinical protocols.

Clinical Evaluation of 3D-Printed Resin Composite, Milled Resin Composite, and Hybrid Ceramic Onlays

Eligibility Criteria

• Age: 18 Months+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients aged 18 years or older with permanent dentition, presenting with at least three posterior teeth indicated for indirect onlay or overlay restorations, with favorable and stable occlusion. Patients should have good oral hygiene and vital, asymptomatic teeth with no sensitivity to percussion. Presence of antagonist teeth is required.

You may not qualify if:

• Patients with severe bruxism, unstable medical conditions, or known allergy to any study materials. Patients unable to attend follow-up visits, pregnant or lactating females, and cases with pulp exposure during caries excavation are excluded.

Sponsors & Collaborators

• Mansoura University: lead

Study Sites (1)

Faculty of Dentistry, Mansoura University

Al Mansurah, Dakhlia, 35516, Egypt

Location

Related Publications (1)

• No publication or citation is available yet for this study

  BACKGROUND

Related Links

• Related Info

MeSH Terms

Conditions

Dental Caries

Condition Hierarchy (Ancestors)

Tooth Demineralization; Tooth Diseases; Stomatognathic Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Masking Details: No masking was applied due to the nature of the restorative interventions. Both the operator and the participants were aware of the type of restorative material used (3D printed CAD/CAM hybrid resin, milled CAD/CAM hybrid ceramic, and indirect resin composite onlays). Outcome assessment was performed by independent examiners.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: A randomized split-mouth parallel design was used. Each patient received three different restorative treatments (3D printed CAD/CAM hybrid resin, milled CAD/CAM hybrid ceramic, and indirect resin composite onlays) allocated randomly to posterior teeth. Each tooth served as an independent experimental unit for comparison of the tested materials.

Study Record Dates

• First Submitted: June 2, 2026
• First Posted: June 8, 2026
• Study Start: September 1, 2024
• Primary Completion: March 1, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: June 12, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)