Wear Resistance of 3D-Printed Crown and Bridge Material

Objectives: 3D Printing is a rapidly growing technology in dentistry. Various dental applications have been developed and they can totally change dental work flow.
Temporary crown and bridge material can be used not only in short term but also in long term in the mouth as a provisional restoration. Therefore, sufficient wear resistance of restorative is required for clinical longevity and aesthetics. The purpose of this study was to evaluate the wear resistance of 3D-printed crown and bridge material.
Methods: GC Temp PRINT(GC), Nextdent C&B (3D systems) and FREEPRINT Temp (Detax) were examined. Specimens (n=4) for the three-body wear test were printed with Asiga 3D-printer and post-cured with the light curing device and settings recommended by the respective manufacturers. Subsequently, they were stored in 37 °C water for 24 hours. Specimens were subjected to 100,000 cycles at a load of 0.84 MPa in a wear simulator. An acrylic plate was used as antagonist, and a slurry of PMMA and glycerin as abrasive medium was applied to the contact area during test performance. Wear value was calculated as the difference in specimen height before and after the three-body wear. Results were analyzed by one-way ANOVA (p<0.05). Afterwards, the specimen surfaces were examined with a FE-SEM.
Results: Average wear value were as follows: GC Temp PRINT: 16.3±6.6 µm;, Nextdent C&B: 176.5±23.4 µm;, FREEPRINT Temp: 85.8±36.8 µm. GC Temp PRINT exhibited significantly lower wear value in comparison to the other materials. SEM images showed that GC Temp PRINT had a higher filler proportion.
Conclusions: GC Temp PRINT had higher wear resistance than the other 3D-printed materials thanks to its uniformly dispersed fillers and the proper silane treatment of the filler surface. This is an important feature for clinical longevity.