Comparative regenerative effects of human dental pulp and periodontal ligament stem cells delivered on collagen–hydroxyapatite scaffolds in rabbit dental defects: An in vivo study

Abstract

Objective: This study aimed to compare the regenerative ability of human dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) when transplanted on collagen–hydroxyapatite (CHA) scaffolds into experimental defects created in the dentition of rabbits.

Methods: A total of 24 male and female white rabbits were divided into four groups (n = 6) of white rabbits: scaffold plus DPSCs, scaffold plus PDLSCs, scaffold alone, and empty-defect control. Before seeding with scaffolds, the human DPSCs and PDLSCs were expanded and characterised using mesenchymal and haematopoietic surface markers. The regeneration was assessed histologically by immunohistochemistry for dentin sialophosphoprotein and vascular endothelial growth factor, and micro computed tomography. One-way analysis of variance was used to test the differences between groups at p < 0.05.

Results: DPSC-treated defects had organised pulp-like tissue, vascular structures, odontoblast-like cells and higher levels of dentin sialophosphoprotein and vascular endothelial growth factor expression than controls. The defects treated with PDLSC showed periodontal ligament fibre organisation, the formation of new cementum, and increased alveolar bone formation. Micro-computed tomography revealed a significant increase in bone volume in the PDLSC group compared with the control group (p < 0.05). The overall regenerative outcomes were better in the cell-seeded scaffold groups as compared to the scaffold-only and empty-defect groups.

Conclusion: In the context of this preclinical study, collagen–hydroxyapatite scaffolds seeded with DPSCs or PDLSCs showed tissue-specific improvement in pulp and periodontal regeneration, respectively. There is a need for quantitative and longer-term studies before clinical application.