Evaluation of total prostheses produced by additive and subtractive methods in terms of geometric precision

Aim: 3D printing technologies, which are frequently used in dental applications today, are of great importance in precision and accuracy in production processes. This study evaluated prosthetic bases produced at different angles and orientations with engraving technology, DLP (Digital Light Processing), and LCD (Liquid Crystal Display) technologies in terms of geometric precision, weight, residual amount, and production time. The compatibility of the produced models with the reference design was evaluated, and the effects of production technology and printing parameters on accuracy were compared. In this way, it is aimed to reveal the advantages and limitations of different production methods and to provide better tissue compatibility in clinical applications. Materials and Methods: In this study, prosthetic bases were fabricated using three different methods: digital light processing (DLP), liquid crystal display (LCD), and engraving. Photopolymerized resin and PMMA disk materials were used in the production. The production was done by creating designs according to specific angles and orientations, and the appropriate orientations were determined for each sample. The fabricated base materials were scanned with an extraoral scanner, and their geometric accuracy was evaluated by comparing the scan data with the reference design. In the engraving method production, 5-axis machine processing was performed using PMMA disks. Material quantities were determined by pre- and post-production weight measurements, and post-production cleaning, polishing, and post-curing processes were performed. The amount of material used and production times were recorded and compared in all processes. Results: The geometric precision of the manufactured prosthesis bases was found to show a statistically significant difference according to the manufacturing technology. Engraving technology was found to have the highest geometric accuracy. When additive manufacturing techniques were compared, it was found that the geometric accuracy of prosthetic pedestals produced with DLP technology was higher than those produced with LCD technology. There were statistically significant differences in pedestal weights, production times, and residual amount according to the production technologies. Pedestals produced by the engraving method showed the lowest pedestal weight and the highest residual amount, while DLP technology was observed to have the shortest production time. Keywords: 3D Technology, Denture base, Additive production, Subtractive production, Geometric precision