EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The additive manufacturing technologies have created huge growth for frontiers research allowing breakthroughs in multidisciplinary sciences connected to bone tissue engineering and bioapplications.1 All technologies must challenge the features demanding by the natural biomimicking of the bone as ceramic composite materials. One of the potent forming technologies include melted material extrusion techniques known as FDM, FFF or FDC. In addition various concepts for production of applicable scaffolds can be found in the literature: i) scaffolds based on pure biocompatible polymers such as PLA (Polylactic acid) or high performance polymer PEEK (Polyether ether ketone) ii) composite scaffolds with biocompatible inorganic phase such as Hydroxyapatite (HAp), calcium phosphates (CaP) or biocompatible glass (BCG).2 After an optimisation study, we have recently developed a HAp highly loaded filament applicable for FDM 3D printers which is planned for iii) production of ceramic HAp scaffolds after debinding of polymeric matrix and sintering HAp to desired density.3 However, from the literature it is known that bone healing occurs if there is a correct anatomical reduction of the fracture ends and a stable fixation. In contact healing, the gap between bone ends is less than 10 µm and interfragmentary strain is less than 2 %. The bone gap healing occurs only if the gap is less than 800 μm to 1 mm, therefore, the accuracy of the 3D printing of bone scaffolds is very important for close match of the defect shape.4 From these reasons we have investigated the dimensions of HAp scaffolds produced from filament containing 50 % wt./wt. of HAp printed with 400 µm nozzle and layer height 300 µm.

ACKNOWLEDGMENT
The financial support of the Slovak Grant Agency for Science VEGA grant No. 1/0342/21 and Slovak Research and Development Agency APVV-16-0341 are greatly appreciated.