Dimensional Accuracy of Dental Casts Fabricated Using Digital Light Processing, Liquid Crystal Display and Fused Deposition Modelling: A Clinical Observational Study

Abstract

Aim. To evaluate and compare the dimensional accuracy of dental casts fabricated using digital light processing (DLP), liquid crystal display (LCD), and fused deposition modelling (FDM) three-dimensional (3D) printing technologies.
Materials And Methods. A clinical observational study was conducted on 14 participants meeting predefined inclusion criteria. Maxillary arches were scanned using an intraoral scanner to obtain STL datasets, which served as the digital reference. Each STL file was used to fabricate three printed casts using DLP, LCD, and FDM technologies, producing a total of 42 printed models. Linear dimensional accuracy was assessed by measuring intermolar width (IMW), intercanine width (ICW), and dental arch length (AL) using an optical multisensory coordinate measuring machine (O-INSPECT CMM, Zeiss). Measurements were repeated three times by the same operator, and the mean values were analysed. Data normality was assessed using the Shapiro–Wilk test, followed by one-way analysis of variance. Effect sizes were calculated to determine the magnitude of intergroup differences.
Results. All three printing technologies produced casts with dimensional deviations that remained within clinically acceptable limits. DLP demonstrated the least numerical deviation from the reference STL dataset across the evaluated parameters, followed by LCD and FDM. Although FDM exhibited comparatively greater deviation, particularly for arch length, no statistically significant differences were observed among the printing technologies for intermolar width (P = 0.657), intercanine width (P = 0.861), or arch length (P = 0.976). Effect size analysis demonstrated minimal influence of fabrication technique on dimensional variability.
Conclusion. Among the investigated systems, DLP demonstrated the highest dimensional accuracy and may be preferred for procedures requiring maximum precision, whereas LCD and FDM provide acceptable alternatives for diagnostic, educational and routine clinical applications.