Comparison of dimensional accuracy of diagnostic trial restoration transfer with four different methods: a randomized clinical trial

Abstract

Background/Objective: Diagnostic trial restorations play a crucial role in restorative dentistry by allowing clinicians to evaluate aesthetics, function, and phonetics before finalizing definitive restorations. These restorations facilitate communication between patients, clinicians, and dental technicians, ensuring treatment alignment and predictable outcomes. The accuracy of transferring diagnostic trial restorations to the oral cavity is essential to maintain the integrity of the planned design. Various fabrication techniques, including conventional silicone matrices and computer-aided design/computer-aided manufacturing (CAD-CAM)-based methods, have been developed to improve transfer precision. However, there is limited evidence directly comparing their dimensional accuracy. This randomized in vivo study aimed to evaluate and compare the accuracy of four commonly used techniques—condensation silicone, addition PVS silicone, transparent PVS silicone, and CAD-CAM combination matrices—by assessing their linear and volumetric discrepancies. Methods: Twenty patients requiring aesthetic rehabilitation of their anterior maxillary teeth participated. The sequence of matrix usage was determined through randomization. Four techniques for transferring diagnostic trial restorations were evaluated: (1) condensation silicone matrix, (2) addition polyvinyl siloxane (PVS) silicone matrix, (3) transparent PVS silicone matrix, and (4) CAD-CAM combination matrix. Dimensional accuracy was assessed by comparing intraoral scans (IOSs) of the transferred restorations to the original diagnostic wax-up. Linear discrepancies were measured at four buccal landmarks (cervical, medial, lower medial, and incisal), and volumetric deviation was evaluated using reverse engineering alignment software. Results: Significant differences were observed among the groups in both linear and volumetric discrepancies (p < 0.05). The CAD-CAM combination matrix showed superior volumetric accuracy, with minimal deviations from the diagnostic wax-up. The addition PVS silicone matrix demonstrated consistent linear accuracy, particularly at the cervical and medial landmarks. The condensation silicone matrix exhibited moderate performance across both linear and volumetric accuracy. The transparent PVS silicone matrix showed the highest variability, with greater volumetric deviations. Conclusions: The study highlights that the choice of matrix material and technique significantly impacts the dimensional accuracy of diagnostic trial restoration transfers. The CAD-CAM combination matrix and the addition PVS silicone matrix demonstrated superior advantages compared to the other techniques. Clinicians should consider the specific requirements of each case, including accuracy and ease of use, when selecting a transfer technique for aesthetic rehabilitations.