3D-printed pre-tapped-hole scaffolds facilitate one-step surgery of predictable alveolar bone augmentation and simultaneous dental implantation

Despite the convenience of one-step surgery for alveolar bone augmentation and simultaneous dental implantation, achieving a suitable bone graft for predictable alveolar bone augmentation and stable dental implant placement via one-step surgery remains a huge challenge. Herein, a novel personalized scaffold with a pre-tapped-hole that could perfectly fit the dental implant was precisely fabricated by 3D printing technology. The biocompatible organic poly(lactic-co-glycolic acid) (PLGA) and osteoconductive inorganic materials (hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP)) were used as composite materials with an appropriate viscosity for pre-tapped-hole scaffold fabrication (PLGA/HA/beta-TCP, PHT). The PHT composite scaffold demonstrated a well-designed structure that could match perfectly with bone defect areas and the titanium screw, and proper mechanical property as high as 67.18 +/- 7.40 MPa in Young's modulus and 4.85 +/- 0.39 MPa in compression stress. Meanwhile, PHT scaffold exhibited excellent in vitro cellular biocompatibility and proper in vivo osteoconductivity in a rabbit bone augmentation model. In addition, results of micro-CT and histological analysis further confirmed that PHT scaffold was able to obtain adequate primary stability provided by the titanium screw, and offer adequate space maintenance ability for new bone formation. Therefore, this study provided a robust and effective strategy of precise 3D printing technology for one-step surgery of predictable alveolar bone augmentation and simultaneous dental implantation.