Accuracy of occlusal relationships in 3D-printed dental casts: A comparative in vitro study.

Purpose: This in vitro study aimed to evaluate the accuracy of occlusal relationships in 3D-printed dental casts, comparing two mounting methodologies.

Materials and methods: Maxillary and mandibular dental casts were scanned and digitized for virtual digital design as reference models. A total of 30 pairs of casts were printed using a digital light synthesis (DLS) 3D printer and mounted either based on hand articulation (Group HA) or using computer-aided design (CAD)-generated articulation pins (Group CAP). Accuracy was assessed by using the root mean square (RMS) values and linear measurements against the reference models.

Results: Group HA demonstrated mean RMS values of 147.9, 133.9, and 166.5 for the canine, second premolar, and second molar regions, respectively, with a mean RMS value of 149.4. Group CAP had RMS values of 398.2, 298.9, and 301.4 for the same regions, respectively, averaging at 332.8. Statistically significant differences were observed between the two groups across all sites. Linear measurements also showed notable discrepancies, especially in Group CAP, with significant differences in vertical dimension when compared to the master standard tessellation language (STL) models.

Conclusions: The mounting methodology influences the accuracy of occlusal relationships in 3D-printed dental casts. Group HA demonstrated greater accuracy and consistency in replicating occlusal relationships compared to Group CAP. These findings underscore the importance of selecting an appropriate mounting methodology for precise replication of occlusal relationships in prosthodontic treatments within digital workflows.