Helal M A, Abdelrahim R A, Zeidan A A. Comparison of Dimensional Changes Between CAD-CAM Milled Complete Denture Bases and 3D Printed Complete Denture Bases: An In Vitro Study. J Prosthodont 2022; DOI: 10.1111/jopr.13538.

3D printing is quicker and more efficient.

The conventional laboratory construction method for complete dentures suffers polymerisation shrinkage of polymethylmethacrylate during processing. With the introduction of computer-aided design and manufacture, subtractive milling and additive 3D printing processes have been developed to overcome the problem of shrinkage.

Using a metal maxillary master cast with three fixed identification points (incisal papilla and left and right first molar region), 30 denture bases were manufactured, 10 by each method of conventional flasking and compression moulding, milling and 3D printing. Measurements showed that milling produced significantly less distortion in both antero-posterior and lateral dimensions. Surface scans of the bases superimposed on an inverted scan of the master model also showed that milled bases were adapted significantly better than either conventional or printed bases.

Milling has the disadvantage of large material losses during processing and the high cost of equipment. While 3D printing is quicker and more clinically efficient, in this study, it had the lowest dimensional accuracy of the three systems tested.