Clinical Performance of 3D-Printed Resin and Zirconia Implant Restorations

This study was designed as a parallel-arm randomized controlled clinical trial to compare the clinical performance of implant-supported restorations fabricated using a novel 3D-printed resin material (CROWNTEC) with that of conventionally milled monolithic zirconia. The investigation focused on single crowns and short-span fixed partial dentures (FPDs) in the mandibular anterior region, where functional and esthetic demands are critical.

Participants meeting predefined inclusion criteria were randomly assigned into two intervention groups: a 3D-printed resin group and a zirconia group. All restorations were produced using a fully digital workflow, including intraoral scanning, CAD design, and standardized manufacturing protocols. Prostheses were delivered as either screw-retained or cement-retained restorations, with careful control of occlusion and prosthetic design parameters.

Patients were followed at baseline, 3, 6, and 12 months, with extended follow-up planned up to 24 months. The primary outcome measure was restoration survival, defined as the absence of failure requiring replacement. Secondary outcomes included technical complications such as fracture, chipping, and screw loosening; biological parameters including plaque index, bleeding on probing, and probing depth; and radiographic assessment of marginal bone level changes. Patient-reported outcomes were also evaluated using a visual analog scale to assess satisfaction with esthetics, comfort, and masticatory function.

By directly comparing a novel additive manufacturing material with an established reference standard, this study addresses a critical gap in the literature regarding the clinical applicability of 3D-printed definitive restorations in implant dentistry. The findings are expected to contribute valuable evidence on the performance, limitations, and potential role of 3D-printed resin materials in modern prosthodontic practice.

Inclusion criteria

• Participants must meet all of the following:
• Age ≥18 years.
• Have one or two osseointegrated dental implants requiring prosthetic restoration.
• Demonstrate stable peri-implant tissues with no signs of inflammation or implant mobility.
• Maintain good oral hygiene and controlled periodontal status.
• Require either:
• A single implant-supported crown, or
• A short-span (maximum 3-unit) implant-supported fixed partial denture (FPD) supported by two implants in the mandibular anterior region.

Exclusion criteria

• Participants are excluded if they have any of the following:
• Severe parafunctional habits (e.g., bruxism).
• Uncontrolled systemic diseases affecting bone metabolism or healing.
• Peri-implantitis or compromised implant stability.
• Requirement for cantilever prostheses or long-span restorations, or FPDs in areas other than the mandibular anterior region.