Figure 1. In (A) photomicrograph showing all root canals of the upper first molar in transversal cross-section. In (B) treated mesial buccal root canal showing formation of loosen connective tissue without presence of odontoblasts. In (C) non-instrumented root canal showing vital pulp characterized by the presence of the layer of odontoblasts. Hematoxylin & eosin (HE)-stained.
