3D printed long-term structurally stable bioceramic dome scaffolds with controllable biodegradation favorable for guided bone regeneration

Alveolar bone loss and insufficient bone mass are major obstacles to the oral implant treatment. Guided bone regeneration (GBR) is an effective and widely used method to solve this problem. Titanium mesh with good 3D space maintenance ability shows excellent effect in the assistance of GBR. Unfortunately, such metal mesh needs to be removed by secondary operation, and the exposure after operation can’t be completely avoided. Thus, it is a big challenge to repair the alveolar bone defects with different shapes and sizes by customization. Herein, the wollastonite bioceramics without and with 6% magnesium doping (CSi, CSi-Mg6) were prepared to fabricate the macroporous dome-like meshes with different CSi/CSi-Mg6 mass ratio (0:100, 16:84, 32:68) via digital light processing-based 3D printing (DLP) technique. The mechanical parameters, biodegradable rate and osteogenic stem cell viability in vitro of the bioceramic scaffolds with different morphologies were also evaluated systematically. The macroporous bioceramic dome- or titanium mesh-assisted osteogenic potentials in the calcined bone granules were evaluated in the rabbit calvarial bone defect models. The experimental results showed that the scaffolds with 16%CSi exhibited satisfactory mechanical properties and promoted the proliferation and differentiation of osteogenic stem cells. The bioactive domes displayed significantly higher osteostimulate activity than the metal mesh in the calcined bone mineral granule systems. The appreciable CSi-Mg6 content (≥84%) in the dome scaffolds could maintain the porous structures after 16 weeks of implantation, and especially the presence of 16% CSi in the bioceramic dome may greatly balance the scaffold biodegradation and restoration treatment. Totally, the 3D printed nonstoichiometric wollastonite-based scaffolds are expected to be the promising candidates to replace titanium mesh in GBR.