Digital analysis of internal fit variation of additively manufactured crown patterns

Abstract

Aim: The purpose of this study was to digitally quantify the consistency and variation of printed resin crown patterns produced by different 3D printers, aiming to evaluate their clinical relevance and accuracy. This was accomplished by evaluating patterns manufactured using three different 3D printers and resin materials, assessing their fit and adaptation through digital scanning and analysis. The objective was to determine the internal and marginal variations of printed crown resin patterns and to identify the printer and material combinations that produce the most consistent and clinically acceptable results. Methods: A prefabricated typodont tooth was prepared for a crown and scanned using an intraoral scanner. From this scan, a crown was designed and the resulting STL file was exported. This 3D file was manufactured using resins indicated for castable patterns on 3 different printers: FotoDent® Cast with the Carbon M2 printer, Form 3 Castable with the Form 2 printer, and Siraya Tech Cast with the ELEGOO Mars 2 Pro 3D printer. Finally, the crown resin patterns were scanned using an intraoral digital scanner (3Shape TRIOS 3) scanner, and crown adaptation was digitally quantified in GeoMagic software. Clinically relevant significance was determined (marginal gap < 50 µm) between resin patterns printed on different printers. Results: Form 3 Castable/Form 2 printer had the lowest mean internal variation at all measurement areas, 21.07 μm at the occlusal, 104.23 μm at the margin, and 37.98 μm at the axial. FotoDent® Cast/Carbon M2 had the largest marginal variation while Siraya Tech Cast/ELEGOO Mars 2 Pro had the largest occlusal variation. Within each material, the largest internal variation was at the marginal area while the lowest value was in the occlusal area. Conclusions: All printed crowns displayed clinically acceptable ranges, but there was a statistically significant difference in the fit between all printers.