Dental Pulp Tissue Engineering in Full-length Human Root Canals

TLDR

The clinical translation of stem‑cell‑based dental pulp regeneration will require injectable scaffolds. The study tested whether stem cells from exfoliated deciduous teeth (SHED) can generate functional dental pulp when injected into full‑length root canals. SHED were mixed with Puramatrix™ or rhCollagen type I scaffolds, injected into full‑length human premolar root canals, and the constructs were implanted subcutaneously into immunodeficient CB‑17 SCID mice. SHED survived and expressed odontoblastic markers within 7–14 days in Puramatrix™ or rhCollagen, formed pulp‑like tissues with odontoblasts producing new tubular dentin throughout the canals, exhibited comparable cellularity and vascularization to native pulps, and overall demonstrate functional odontoblast differentiation, indicating this strategy could aid root completion in necrotic immature teeth.

Abstract

The clinical translation of stem-cell-based dental pulp regeneration will require the use of injectable scaffolds. Here, we tested the hypothesis that stem cells from exfoliated deciduous teeth (SHED) can generate a functional dental pulp when injected into full-length root canals. SHED survived and began to express putative markers of odontoblastic differentiation after 7 days when mixed with Puramatrix™ (peptide hydrogel), or after 14 days when mixed with recombinant human Collagen (rhCollagen) type I, and injected into the root canals of human premolars in vitro. Roots of human premolars injected with scaffolds (Puramatrix™ or rhCollagen) containing SHED were implanted subcutaneously into immunodeficient mice (CB-17 SCID). We observed pulp-like tissues with odontoblasts capable of generating new tubular dentin throughout the root canals. Notably, the pulp tissue engineered with SHED injected with either Puramatrix™ or rhCollagen type I presented similar cellularity and vascularization when compared with control human dental pulps. Analysis of these data, collectively, demonstrates that SHED injected into full-length human root canals differentiate into functional odontoblasts, and suggests that such a strategy might facilitate the completion of root formation in necrotic immature permanent teeth.