Third Teeth The evidence record
T2

Bioengineered tooth germ (organ germ transplant)

Tsuji lab lineage (Ikeda et al., RIKEN / Tokyo University of Science) · whole-tooth · Animal result

Status

Fully functional whole-tooth replacement demonstrated in adult mice (2009). Human cell sourcing and developmental control remain major gaps; no human protocol has been proposed. A 2025 study by Kim et al. shows that lingual-buccal positional memory persists in dissociated and reaggregated mouse dental mesenchyme, adding a spatial-patterning requirement to reconstitution protocols. A 2024 chemically defined culture study by Zhang et al. supports mouse tooth reconstitution and BMP-driven enamel induction, and a 2025 study by Zhang and Yelick reports tooth-like mineralized tissues, including periodontal-ligament-like tissue with Sharpey's fibers, from recellularized decellularized porcine tooth bud scaffolds in adult minipigs. A 2025 study by Birjandi and Sharpe finds that the inductive tooth germ secretome and small extracellular vesicles shift epithelial signaling but are not sufficient to replace living mesenchyme for tooth induction in mice.

What would change this assessment

Independent replication of tooth formation in a large animal by a group with no commercial stake, or a credible human cell-sourcing plan.

Tier history

  • 2009-08-03 T2 A transplanted bioengineered tooth germ erupted, occluded, and responded to mechanical and pain stimuli in an adult mouse (Ikeda et al., PNAS).

Sources on file

  1. Ikeda E, Morita R, Nakao K, et al. (2009). Fully functional bioengineered tooth replacement as an organ replacement therapy. Proceedings of the National Academy of Sciences 106(32):13475-13480. doi:10.1073/pnas.0902944106
  2. Kim EJ, Kim HY, Lee S, et al. (2025). Prespecified dental mesenchymal cells for the making of a tooth. International Journal of Oral Science 17:67. doi:10.1038/s41368-025-00391-7
  3. Zhang Z, Hu H, Xu Z, et al. (2024). A chemically defined culture for tooth reconstitution. Advanced Science 12(3):e2404345. doi:10.1002/advs.202404345
  4. Zhang W, Yelick PC (2025). In vivo bioengineered tooth formation using decellularized tooth bud extracellular matrix scaffolds. Stem Cells Translational Medicine 14(2):szae076. doi:10.1093/stcltm/szae076
  5. Birjandi AA, Sharpe PT (2025). The Secretome of the Inductive Tooth Germ Exhibits Signals Required for Tooth Development. Bioengineering 12(2):96. doi:10.3390/bioengineering12020096

← All programs