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Updated: Mar 13, 2026
Development of a Direct Pulp-capping Model for the Evaluation of Pulpal Wound Healing and Reparative Dentin Formation in Mice
Published on: January 12, 2017
Regenerative Dentistry: Animal Model for Regenerative Endodontology
Nisarat Ruangsawasdi1, Matthias Zehnder2, Raphael Patcas3
1Oral Biotechnology & Bioengineering, Cranio-Maxillofacial and Oral Surgery, Center for Dental Medicine, University of Zurich, Zurich, Switzerland; Department of Pharmacology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Background:
Ectopic tissue has been observed frequently in human root canal specimens when cell homing studies were performed at the dorsum of rodents. In contrast, pulp-like tissue formed when immature teeth were implanted on top of the rat calvaria. It was surmised, yet not tested, that the implantation site might affect tissue ingrowth.
Methods:
Four root sections from human immature molars cleaned with 5% sodium hypochlorite (NaOCl) followed by 17% ethylenediaminetetraacetic acid (EDTA) were implanted per rat (n = 5). Two specimens were placed at the dorsum (control), while the other two specimens were implanted at the calvaria. After 6 weeks, the specimens were investigated for histological structure, immunoreactivity to dentine sialoprotein (DSP) and bone sialoprotein (BSP), per-area percentage of tissue ingrowth, and gene expression (DSPP, COL1, NGF and VEGF). Data were statistically compared.
Results:
Tooth specimens placed at the calvaria generally showed pulp-like tissue and odontoblast-like cells at the dentinal wall where DSP and BSP immunoreactivity were intense. The area of tissue ingrowth was significantly larger in the specimens placed at the calvaria compared to those placed at the dorsum. DSPP was the only gene that was upregulated significantly when specimens were implanted at the calvaria.
Conclusion:
Our findings suggest that the calvarial site is superior to the dorsum to study pulp regeneration in human teeth in the rat.
