IN VITRO MECHANICAL ASSESSMENT OF 3D-DESIGNED PRINTED TEMPORARY BRIDGE CONNECTORS

Alexia-Ecaterina Cârstea, Robert-Cătălin Ciocoiu, Vlad-Gabriel Vasilescu, Corina Vâlcu, Lucian-Toma Ciocan, Silviu-Mirel Pițuru, Ana-Maria Cristina Țâncu, Marina Imre

ABSTRACT
Aim of the study This study aims to assess the clinical applicability of digital technologies in provisional prosthodontics and to evaluate the mechanical behavior of three-dimensionally printed provisional bridges, with emphasis on the influence of connector thickness and design.
Materials and methods A structured questionnaire was administered to prosthodontics residents from Romanian university centers to evaluate their level of experience and perception of digital workflows, including intraoral scanning, CAD/CAM design, and 3D printing. The experimental component involved the fabrication of four-unit provisional bridges using a fully digital workflow and 3D printing technology. Three connector thicknesses (2.0 mm, 2.5 mm, and 3.0 mm) were tested under static vertical loading using a universal testing machine, and mechanical parameters were recorded.
Results Questionnaire findings indicated limited practical experience with digital technologies among residents, particularly in CAD/CAM design and 3D printing, despite a consistently high interest in acquiring these competencies. Mechanical testing revealed that fracture resistance did not increase linearly with connector thickness. Bridges with 3.0 mm connectors demonstrated superior resistance when symmetrically designed, whereas 2.5 mm connectors exhibited inferior and less predictable mechanical behavior due to asymmetric material distribution. The 2.0 mm connectors showed consistent stiffness.
Conclusions Digital technologies play an increasingly important role in provisional prosthodontics. While current educational experience remains limited, the strong interest among residents highlights the need for structured digital training. Mechanically, connector geometry and balanced design are more critical than thickness alone for the performance of 3D-printed provisional bridges. With appropriate design and clinical indication, digitally fabricated provisional restorations represent a reliable option in modern prosthodontic practice.

DOI : 10.62610/RJOR.2025.4.17.8