Advances in Digital Restorative Dentistry: Evaluation of Clinical Outcome Parameters of CAD/CAM and 3D-Printed Inlays, Onlays, and Veneers-Scoping Review.

Abstract

Background: Digital workflows have revolutionized restorative dentistry, computer-aided design and computer-aided manufacturing (CAD/CAM) milling, and three-dimensional (3D) printing provide alternatives to conventional methods of fabrication of inlays, onlays, and veneers. However, comparative evidence of their clinical performance remains scattered.

Aim: This scoping review aimed to map and synthesize current evidence on the clinical outcomes of CAD/CAM- and 3D-printed inlays, onlays, and veneers, focusing on adaptation, strength, esthetics, and workflow efficiency.

Methodology: This scoping review followed the methodological framework proposed by Arksey and O'Malley, with refinements suggested by Levac et al., and was reported in accordance with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews). A comprehensive search was performed in PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar for studies published from January 2000 to June 2025. Eligible studies included in vitro, clinical, and case-based reports that evaluated CAD/CAM or 3D-printed inlays, onlays, or veneers. Data were charted and analyzed thematically according to restoration type, fabrication method, material, and reported outcomes.

Result: Thirty studies were included, mainly in vitro. Inlays showed clinically acceptable adaptation, with 3D printing achieving accuracy comparable to milling, while ceramics offered superior hardness. Onlays yielded mixed outcomes: pressable ceramics had higher strength, but 3D-printed onlays often showed better adaptation. Veneers demonstrated the greatest potential for 3D printing, with printed zirconia and lithium disilicate performing well. CAD/CAM was faster and well established, whereas 3D printing provided greater customization but longer fabrication times.

Conclusion: In conclusion, both CAD/CAM and 3D printing are capable of producing inlays, onlays, and veneers with clinically acceptable accuracy and strength. CAD/CAM remains the most established and reliable technique, particularly for ceramics, whereas 3D printing shows potential to enhance adaptation and customizability, especially for veneers. Further clinical trials are essential to validate long-term outcomes.