Comparison of the intaglio surface accuracy of occlusal veneers fabricated using two different techniques to restore severe occlusal tooth wear: An in vitro study

Abstract

Statement of problem: Intaglio surface accuracy is essential for the proper fit and clinical performance of occlusal veneers. Comparative data on subtractive and additive methods for occlusal veneers fabricated from patient-derived casts with severe tooth wear are limited. Purpose: The purpose of this in vitro study was to evaluate the trueness and precision of occlusal veneers fabricated by subtractive milling (Tetric CAD; Ivoclar AG) and additive manufacturing (Saremco print CROWNTEC; Saremco Dental AG) in a severely worn molar using a patient-derived cast under laboratory conditions. Material and methods: A digital scan of the mandibular first molar tooth of a patient with severe occlusal wear was obtained using an intraoral scanner. Occlusal veneers were digitally designed and fabricated by milling (n=20) or 3-dimensional printing (n=20). Intaglio surface scans were compared with the reference design in the Geomagic Control X software program to assess trueness; precision was determined by pairwise alignment within groups. Data normality was assessed with Kolmogorov-Smirnov and Shapiro-Wilk tests, and groups were compared with the Mann-Whitney U test (α=.05). Results: Trueness was significantly higher in the milling group (P<.05), while no significant difference in precision was observed (P>.05). Both materials showed trueness values within clinically acceptable limits (≤200 µm). Conclusions: Subtractive milling produced more accurate intaglio surfaces than additive manufacturing, though both methods demonstrated acceptable adaptation and similar reproducibility. Although both methods appear to be clinically applicable, subtractive manufacturing offers higher trueness, whereas additive manufacturing provides advantages in material and cost efficiency.