Performance of Reinforced 3D-Printed Versus Direct Bulk-Filled Resin Composites for Restoring Extensive Class II Cavities in Vital Molars

Summary

Most published research on 3D-printed restorative materials is laboratory-based, focusing primarily on mechanical performance and material properties under controlled conditions. While such studies provide important foundational data, they do not fully replicate the complexity of the oral environment. Only a limited number of clinical investigations have directly compared 3D-printed restorations with conventional direct composite restorations in Class II cavities Furthermore, the integration of a digital workflow introduces additional costs and time requirements related to equipment, software, and training. These factors must be justified by demonstrable improvements in clinical outcomes or cost-effectiveness. By evaluating both clinical performance and economic impact, this trial aims to generate practical, real-world evidence that can guide clinicians in selecting appropriate restorative materials and techniques for routine dental practice.

Conditions

• Class II Lesions
• 3D Printing
• Bulk Fill
• Proximal Cavities of Posterior Teeth
• Composite Restorations

Interventions

OTHER

3D-printed Ceramic reinforced resin restoration

Tooth preparation for indirect inlay restorations follows conservative restorative principles, with the primary objective of eliminating carious tissue and unsupported enamel while preserving as much healthy tooth structure as possible. The preparation design emphasizes mechanical stability, stress distribution, and optimal seating of the final restoration. Cavity walls are shaped with a slight occlusal divergence of approximately 6-10°, facilitating proper insertion and seating of the inlay without compromising retention. The pulpal floor is prepared flat to enhance resistance form, and all internal line angles are rounded to minimize stress concentration within both the tooth and the restorative material. Cavosurface margins are ideally prepared as supragingival butt-joint margins whenever clinically feasible, promoting periodontal health, improved isolation, and easier finishing procedures. Cuspal coverage is generally avoided in inlay preparations to maintain maximum tooth integrit

OTHER

bulk fill composite

For restoration of Class II cavity preparations, a sectional metal matrix system (TOR VM, Russia) will be used to properly reestablish proximal anatomy and contact. The system includes a round separation ring and a pre-contoured metal band designed to reproduce natural proximal contours. A properly sized wedge is inserted to ensure optimal gingival adaptation of the matrix band and to prevent overhangs. The cavity is thoroughly rinsed with water before proceeding with adhesive procedures. Selective enamel etching is performed using 37% phosphoric acid gel applied to enamel margins for 15 seconds, followed by thorough rinsing and gentle air-drying. A universal adhesive system, Tetric N-Bond Universal (Ivoclar Vivadent AG), is then applied in two consecutive layers. Each layer is actively rubbed for 10 seconds, gently air-dried for 5 seconds, and light-cured for 20 seconds to ensure adequate polymerization and bond strength. Restoration is completed using Tetric N-Ceram Bulk Fill resin c

Sponsors & Collaborators

• Ahmed Reda Abd EL Rahman

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

22 Years

Max Age

45 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-02-20

Primary Completion

2027-09-01

Completion

2027-10-01