The study was designed to evaluate the effects of a liquid-type scanning-aid material on the accuracy and time efficiency of intraoral digital impressions compared to those of two different types of powder scanning-aid material and the powder-free scanning method. Three reference models (inlay, onlay, and bridge) were fabricated by a 3D printer and scanned with a model scanner to make the reference datasets. Four experimental groups (application of ScanCure, VITA, IP, and no treatment) were established, and the scans were acquired (each n = 5) using the Trios 3® (3 Shape, Copenhagen, Denmark). All scan data were digitally superimposed with the reference data (trueness, n = 5), and group comparisons were performed for each group (precision, n = 10). Time efficiency was evaluated by comparing the working times for scanning the models. The liquid-type ScanCure group showed fewer errors than the IP and VITA groups in all three reference models. Particularly, in the inlay model, the ScanCure group showed high accuracy compared to the powder-type groups (IP and VITA) with statistical significance (p < 0.001). The working time of the no-treatment group was longer than that of the agent groups in all reference models (p < 0.001). Notably, in the bridge model, the working time of the ScanCure group was shorter than that of the IP and VITA groups. Unlike other spray-type scanning-aid materials, this liquid-type material has the advantage of being thinly and uniformly applied to the object surface at the time of use. These findings suggest that the liquid-type scanning-aid material would be more accurate in achieving shape reproducibility using an intraoral scanner than the other two spray-type groups.
Keywords: intraoral scanners; precision; root mean square (RMS); scanning-aid materials; trueness.