predentin

noun
pre·​den·​tin | \ -ˈdent-ᵊn How to pronounce predentin (audio) \
variants: or predentine \ -​ˈden-​ˌtēn, -​den-​ˈ How to pronounce predentine (audio) \

Medical Definition of predentin

: immature uncalcified dentin consisting chiefly of fibrils