Marginal and internal discrepancies associated with carbon digital light synthesis additively manufactured interim crowns

• Published in: The Journal of prosthetic dentistry 2023-07, Vol.130 (1), p.108.e1-108.e6
• Main Authors: Khanlar, Leila Nasiry, Barmak, Abdul Basir, Oh, Youngju, Mendha, Umar, Yared, Sami, Zandinejad, Amirali
• Format: Article
• Language: English
• ISSN: 0022-3913; 1097-6841
• DOI: 10.1016/j.prosdent.2023.04.007

The carbon digital light synthesis (DLS) or continuous liquid interface production (CLIP) technology is an innovative additive manufacturing technology using oxygen-inhibited photopolymerization to create a continuous liquid interface of unpolymerized resin between the growing component and the exposure window. This interface eliminates the need for an incremental layer-by-layer approach, allowing for continuous creation and increased printing speed. However, the internal and marginal discrepancies associated with this new technology remain unclear. The purpose of this in vitro study was to evaluate the marginal and internal discrepancies by using the silicone replica technique of interim crowns fabricated by 3 different manufacturing technologies: direct light processing (DLP), DLS, and milling. A mandibular first molar was prepared, and a crown was designed with a computer-aided design (CAD) software program. The standard tessellation language (STL) file was used to create 30 crowns from the DLP, DLS, milling technologies (n=10). The gap discrepancy was determined using the silicone replica approach, with 50 measurements made with a ×70 microscope for each specimen for the marginal and internal gaps. The data were analyzed using 1-way ANOVA, followed by the Tukey HSD post hoc test (α=.05). The DLS group had the least marginal discrepancy compared with the DLP and milling groups (P.05). The manufacturing technique had a significant effect on both internal and marginal discrepancies. The DLS technology showed the smallest marginal discrepancies.