Microstructure and Surface Characteristics of Short- Fiber Reinforced CAD/CAM Composite Blocks

Objective: The aim was to investigate certain surface properties and microstructure of an experimental short fiber-reinforced CAD/CAM composite block (SFRC) in comparison with different CAD/CAM, 3D-printing and manually-made commercial composites (Cerasmart 270, GC Temp PRINT, Pro3dure GR-17, Essentia U, Gradia Plus and everX Flow).

Methods: A wear-test was performed using a chewing-simulator with 15000 cycles. Wear depth (n=6) was assessed by 3D optical-profilometer. Surface roughness (SR) before and after wearing-test was evaluated. A Vickers-indenter was utilized for evaluating surface microhardness (VH) and glossmeter was utilized to measure the surface gloss at 60°. The surface microstructure of each composite was investigated with SEM. Data were statistically analyzed with analysis of variance ANOVA (p=0.05).

Results: Significant differences in the surface properties were found according to the type of composite (p⟨0.05). Cerasmart 270 exhibited the highest VH (94.8 V) and lowest SR (0.18 Ra) values (p⟨0.05) among the composites tested. The lowest wear depth measurement was located for GC Temp PRINT (19.3 μm) which was not significantly different (p⟩0.05) from Cerasmart 270 (20.7 μm).

Conclusion: Incorporation of fibers to the composite of the CAD/CAM block did not negatively influence the surface characteristics of composite.