Korean J Dent Mater.  2023 Sep;50(3):179-190. 10.14815/kjdm.2023.50.3.179.

Wear resistance of dental temporary restorations manufactured using different additive manufacturing technologies

• Choi MJ
• Kwon JS

• KMID: 2546961
• DOI: http://doi.org/10.14815/kjdm.2023.50.3.179

Abstract

Recently, the digital industry has established itself as a major technology in the field of dentistry, while additive manufacturing (AM), commonly known as 3D printing. Temporary dental restorations are being produced using various additive manufacturing technologies. Also, changes in eating habits expose these temporary restorations to various acidity. Thus, this study was to investigate that wear resistance of dental temporary restorations manufactured using different additive manufacturing technologies according to the acidity of artificial saliva. A total of 120 rectangular parallelepipeds specimens were prepared with three different types of printing method used for the dental resin crown production: Stereo Lithography Apparatus (SLA), Digital Light Processing (DLP), Fused Deposition Modelling (FDM). The antagonists were made of zirconia and cobalt–chrome alloy. Each specimen was then loaded at 5 kg for 20,000 cycle chewing simulations with 5 mm vertical descending movement and 2 mm horizontal movement. The wear resistance test through chewing simulator was conducted in two different pH of 4 and 6. The SLA and DLP group showed no significant difference, however, the FDM group showed significantly increased maximal depth loss and volume loss of wear compared to the other two samples (p<0.05). In the presence of pH 4.0, all specimens significantly showed the wear volume loss and maximal depth loss values were significantly increased (p<0.05), regardless of methods of producing them. There was no significant difference in volume loss between the abrader (p>0.05), but when looking at the specimens, volume loss and depth loss deviation were generally lower when zirconia was used than when the CoCr alloy was used as the abrader. In conclusion, despite the limitations with this in vitro experiment, the SLA and DLP group showed greater mechanical properties compared to the FDM group. The acidic pH environment resulted in more destructive and weak mechanical properties in all groups. When temporary restorations clinically used in additive manufacturing technology, it is believed that it is necessary to determine the method of additive manufacturing and pay attention to acidity.

Keyword

Additive manufacturing; Temporary restoration; Acidity; Wear resistance