evaluation of the distribution patterns of silver grains , resulting from the incorporation of [ 3h ] -thymidine into newly synthesized dna within tooth organs in vitro , resulted in identification of two proliferation centers : ( 1 ) an inner center consisting of inner enamel epithelial cells ( i.e. , preameloblasts ) and predontoblasts ; and ( 2 ) an outer center consisting of outer enamel epithelium and adjacent mesenchyme .
C0040426
tooth
C0011350
enamel