Dentin caries beneath enamel cavity(tg ●Z= destructive zone ●P= Penetrative zone ●D= Demineralizative zone ●T= Translucent zone ●R= Reparative dentin Department of Oral Pathology, Shandong University http://1.51.214.13Department of Oral Pathology, Shandong University 9 http://1.51.214.13 Z=destructive zone P= Penetrative zone D=Demineralizative zone T=Translucent zone R=Reparative dentin