3D-Printed Hydroxyapatite and Tricalcium Phosphates-Based Scaffolds for Alveolar Bone Regeneration in Animal Models: A Scoping Review

Abstract

Three-dimensional-printed scaffolds have received greater attention as an attractive option compared to the conventional bone grafts for regeneration of alveolar bone defects. Hydroxyapatite and tricalcium phosphates have been used as biomaterials in the fabrication of 3D-printed scaffolds. This scoping review aimed to evaluate the potential of 3D-printed HA and calcium phosphates-based scaffolds on alveolar bone regeneration in animal models. The systematic search was conducted across four electronic databases: Ovid, Web of Science, PubMed and EBSCOHOST, based on PRISMA-ScR guidelines until November 2021. The inclusion criteria were: (i) animal models undergoing alveolar bone regenerative surgery, (ii) the intervention to regenerate or augment bone using 3D-printed hydroxyapatite or other calcium phosphate scaffolds and (iii) histological and microcomputed tomographic analyses of new bone formation and biological properties of 3D-printed hydroxyapatite or calcium phosphates. A total of ten studies were included in the review. All the studies showed promising results on new bone formation without any inflammatory reactions, regardless of the animal species. In conclusion, hydroxyapatite and tricalcium phosphates are feasible materials for 3D-printed scaffolds for alveolar bone regeneration and demonstrated bone regenerative potential in the oral cavity. However, further research is warranted to determine the scaffold material which mimics the gold standard of care for bone regeneration in the load-bearing areas, including the masticatory load of the oral cavity.

Keywords: 3D printing; biomaterial; bone regeneration; hydroxyapatite; in vivo; tricalcium phosphates.

Figure 1

PRISMA flow diagram depicting the results of the search strategy.

Figure 2

Histomorphometric evaluation at 4 and 8 weeks. The 3DS group showed a higher value of total amount of bone than PS and NS groups at 4 weeks. At 8 weeks, the greatest total amount of bone was in the 3DS group, followed by the PS and NS groups. 3DS: 3D-printed HA/TCP; PS: Particle-type substitute (OSTEON 3, Genoss^®, Suwon, Korea); NS: Untreated defect [43].

Figure 3

Radiological evaluation at 4 and 8 weeks. The 3DS and PS groups showed greater values of the total amount of bone than the NS group at 4 weeks. There were no significant differences in the amounts of new bone at 8 weeks among all the groups. The three groups from the highest to least relative total amounts of bone were: 3DS, PS and NS. 3DS: 3D-printed HA/TCP; PS: Particle-type substitute (OSTEON 3, Genoss^®, Suwon, Korea); NS: Untreated defect [43].