Analyzing the accuracy of a cross-mounting technique utilizing digitized interocclusal records.

Abstract

Purpose: To compare the accuracy of a partially digital cross-mounting workflow of direct scans of interocclusal records to a conventional workflow by analyzing the deviations of sequentially cross-mounted casts.

Materials and methods: A set of reference casts, comprising maxillary and mandibular full-arch prepared casts and interim prostheses, was articulated, mounted, and scanned to generate four reference casts for cross-mounting. In the conventional approach, 15 sets of these four casts were printed. Polyvinylsiloxane (PVS) records were made using the reference casts and utilized for sequential cross-mounting. In the partially digital group, the same PVS interocclusal records were scanned and used for digital cross-mounting via design software. The mean deviations of both groups from the reference cast were analyzed using a 3D inspection software program. Statistical tests, including paired t-test and analysis of variance (ANOVA), were conducted to compare the average discrepancies between the two groups and to evaluate discrepancies in the anterior and posterior regions (α = 0.05).

Results: The range of discrepancies was similar in both the conventional and partially digital groups. The final set of related casts had a mean deviation of 201.58 ± 136.98 mm in the conventional workflow and 248.69 ± 164.71 mm in the partially digital workflow. No statistically significant difference was found between conventional and partially digital groups (p = 0.091). Error propagation was examined by comparing discrepancies at each step within the cross-mounting process. In the conventional group, no significant difference was found (p = 0.148), but a significant difference was found among groups in the partially digital group at each step of sequential mounting (p < 0.001). A significant difference was observed between anterior and posterior deviations in the partially digital group (p < 0.001), but not in the conventional group (p = 0.143).

Conclusions: The study reveals that there is no statistically significant difference between conventional and partially digital cross-mounting workflows. However, within the partially digital group, a significant difference in deviation emerges across cross-mounting steps, with increased deviation in the anterior region.