Wear Resistance of 3D Printing Resin Material Opposing Zirconia and Metal Antagonists

Abstract

3D printing offers many advantages in dental prosthesis manufacturing. This study evaluated the wear resistance of 3D printing resin material compared with milling and conventional resin materials. Sixty substrate specimens were prepared with three types of resin materials: 3D printed resin, milled resin, and self-cured resin. The 3D printed specimens were printed at a build angle of 0° and 100 μm layer thickness by digital light processing 3D printing. Two kinds of abraders were made of zirconia and CoCr alloy. The specimens were loaded at 5 kg for 30,000 chewing cycles with vertical and horizontal movements under thermocycling condition. The 3D printed resin did not show significant difference in the maximal depth loss or the volume loss of wear compared to the milled and the self-cured resins. No significant difference was revealed depending on the abraders in the maximal depth loss or the volume loss of wear. In SEM views, the 3D printed resin showed cracks and separation of inter-layer bonds when opposing the metal abrader. The results suggest that the 3D printing using resin materials provides adequate wear resistance for dental use.

Keywords: 3D printing; CAD/CAM; metal; resin; wear; zirconia.

Figure 1

3D printed resin specimens were fabricated from a DLP 3D printer. (a) preprocessing before 3D printing; (b) printed specimens on build platform in the 3D printer; and (c) 3D printed specimens after primary wash.

Figure 2

The zirconia abraders were fabricated by milling, and the metal abrader was 3D printed, invested, and cast into a CoCr alloy. (a) computer assisted design for the abraders; (b) calculation and arrangement on CAM software (hyperDENT^® version 7.4, FOLLOW-ME! Technology GmbH, Munich, Germany) for the zirconia abrader; (c) the zirconia abrader inside a block after milling; (d) sacrifice patterns made of castable 3D printing resin for the metal abraders.

Figure 3

The wear volume loss of the materials against the zirconia and the metal abraders. The length of the box represents the interquartile ranges (IQRs) and the horizontal black line in the box stands for the median. The vertical lines extend to the maximum and minimum values.

Figure 4

The maximal wear depth loss of the materials against the zirconia and the metal abraders. The length of the box represents the IQRs and the horizontal black line in the box stands for the median. The vertical lines extend to the maximum and minimum values.

Figure 5

SEM images of the worn surfaces of the materials against the zirconia abrader. (a) 3D printed resin (original magnification ×50); (b) 3D printed resin (original magnification ×1000); (c) milled resin (original magnification ×50); (d) milled resin (original magnification ×1000); (e) self-cured resin (original magnification ×50); (f) self-cured resin (original magnification ×1000).

Figure 6

SEM images of the worn surfaces of the materials against the metal abrader. (a) 3D printed resin (original magnification ×50); (b) 3D printed resin (original magnification ×1000); (c) milled resin (original magnification ×50); (d) milled resin (original magnification ×1000); (e) self-cured resin (original magnification ×50); (f) self-cured resin (original magnification ×1000).