Printable And Machinable Dental Restorative Composites For Cad/Cam Application-Comparison Of Mechanical Properties, Fractographic, Texture And Fractal Dimension Analysis

Thanks to the continuous development of light-curing resin composites it is now possible to print permanent single-tooth restorations. The purpose of this study was to compare resin composites for milling -Gandio Blocks (GR), Brilliant Crios (CR) and Enamic (EN) with resin composite for 3D printing-Varseo Smile Crown plus (VSC). Three-point bending was used to measure flexural strength (sigma(f)) and flexural modulus (E-f). The microhardness was measured using a Vickers method, while fractographic, microstructural, texture and fractal dimension (FD) analyses were performed using SEM, optical microscope and picture analysis methods. The values of sigma(f) ranged from 118.96 (+/- 2.81) MPa for EN to 186.02 (+/- 10.49) MPa for GR, and the values of E-f ranged from 4.37 (+/- 0.8) GPa for VSC to 28.55 (+/- 0.34) GPa for EN. HV01 ranged from 25.8 (+/- 0.7) for VSC to 273.42 (+/- 27.11) for EN. The filler content ranged from 19-24 vol. % for VSC to 70-80 vol. % for GR and EN. The observed fractures are typical for brittle materials. The correlation between FD of materials microstructure and E-f was observed. sigma(f) of the printed resin depends on layers orientation and is significantly lower than sigma(f) of GR and CR. E-f of the printed material is significantly lower than E-f of blocks for milling.