Amelogenin as a regenerative endodontic molecule for immature teeth with apical periodontitis. An experimental study

Vitality of the dentin-pulp complex depends on cell activity and signalling processes. Amelogenin protein regulates cell signalling pathways during tooth development by activating the Wnt/β-catenin intercellular signalling pathway. This study aimed to regenerate a vascularized pulp using recombinant amelogenin protein, in necrotic root canals by cell homing. Access opening was performed for a total of 120 root canals and were left open to become contaminated with oral microbes for 14 days then cleaned. Canals were divided into 2 groups; in the First group, the canals were filled with amelogenin, while in the 2nd group the canals were left empty. Samples were evaluated histologically and with immunodetection of Sox2, Oct4, Vascular endothelial growth factor (VEGF), Wnt1a, Wnt 3a, Wnt 10b, and Glial Fibrillary Acidic Proteins (GFAP). IC50 was used to determine the cytotoxicity of amelogenin. Regenerated dense cellular tissue was seen in the apical part of amelogenin-treated root canals, and regenerated delicate vascularized tissue was observed in the radicular and pulp chamber. Cells found in the regenerated soft tissue expressed Wnt family members that regulate stem cell pluripotency. Also, Sox2 and Oct4, Pluripotency markers, could be identified in the newly formed apical papilla and dental follicle. Furthermore, VEGF in the regenerated pulps indicated neovascularization. While the GFAP immune reactivity demonstrated that the neuro-sensory organ was being replicated in the regenerated dental pulps. Finally, IC50 test showed that recombinant amelogenin protein has a safe dose at high-level concentrations. Recombinant amelogenin protein induces pulp regeneration most likely from the Sox2 identified stem cells within the apical papilla and can enhance apex formation in non-vital immature teeth.