Accuracy of Three-Dimensional (3D) Printed Dental Digital Models Generated with Three Types of Resin Polymers by Extra-Oral Optical Scanning

Abstract

Digital impression devices are used alternatively to conventional impression techniques and materials. The aim of this study was to evaluate the precision of extraoral digitalization of three types of photosensitive resin polymers used for 3D printing with the aid of a digital extraoral optical scanner. The alignment of the scans was performed by a standard best-fit alignment. Trueness and precision were used to evaluate the models. The trueness was evaluated by using bias as a measure and the standard deviation was used to evaluate the precision. After assessing the normality of the distributions, an independent Kruskal–Wallis test was used to compare the trueness and precision across the material groups. The Mann–Whitney test was used as a post-hoc test for significant differences. The result of the analysis showed significant differences (U = 66, z = −2.337, p = 0.019) in trueness of mesiodistal distances. Upon visual inspection of the models, defects were noticed on two out of nine of the models printed with a photosensitive polymer. The defects were presented as cavities caused by air bubbles and were also reflected in the scans. Mean precision did not vary too much between these three photosensitive polymer resins, therefore, the selection of 3D printing materials should be based on the trueness and the required precision of the clinical purpose of the model.

Spatial Trueness Evaluation of 3D-Printed Dental Model Made of Photopolymer Resin: Use of Special Structurized Dental Model

“…However, all models were assessed one month after printing in a study by Mangano et al, leading to dimensional changes caused by aging [ 49 ]. Furthermore, the information on the printing material used was not clearly identified in either study [ 50 ]. The DLP 800d printer was assessed first, to our knowledge, and its overall 3D deviation was slightly lower than the Perfactory printer.…”

The Effect of Stacking on the Accuracy of 3D-Printed Full-Arch Dental Models

“…Dimensional accuracy for diagnostic use and treatment planning [40], and procedures such as the fitting of indirect restorations to prepared tooth structures [21] is of paramount clinical importance. Accordingly, the stacked models are deemed unsuitable for high precision, full arch applications, irrespective of the model's sequence within the stack.…”

3D printing of bone and cartilage with polymer materials

“…The molecules are scattered and cross-linked together like a fence. When the photosensitive resin is irradiated by ultraviolet light, the photo-initiator absorbs energy, forms excited molecules, and decomposes active groups ( Bud et al, 2021 ). Moreover, it is manifested as the transformation of colloidal resin into a solid object.…”