Regenerative Strategies for Enamel Defects via In Vitro and In Vivo Approaches

Abstract

Enamel loss affects approximately 90% of individuals during their lifetime and is irreversible due to the loss of enamel-producing ameloblast cells after tooth eruption. Current treatments are limited to restorative interventions, highlighting the need for regenerative approaches. Amelogenesis is a tightly regulated developmental process; disruptions in these pathways can result in disorders such as Amelogenesis Imperfecta (AI). Building upon our previous work demonstrating differentiation and maturation of ameloblasts from human induced pluripotent stem cells (hiPSCs), we generated disease-relevant hiPSC-derived organoid models of AI through CRISPR-Cas9-mediated knockout of AMELX and DLX3. These models were used to investigate the roles of key enamel-associated genes during human ameloblast differentiation. To advance these findings toward the clinic, we established a novel orthotopic implantation model for enamel-producing organoids within the murine oral cavity, an environment that remains largely unexplored for regenerative dentistry approaches. This platform provides a foundation for future in vivo evaluation of organoids. These studies establish complementary in vitro and in vivo platforms for investigating enamel development and amelogenesis imperfecta and provide a foundation for the future development of regenerative therapies for irreversible enamel defects.