Ahmad Tehrani Endo cases Long second premolar Crack pulpal floor Intracanal placing Tough molar Super erupted Molar Silver point Calcified molar Necrotic case Porcelain onlay Anterior MTA AP Case Part 1 AP Case Part 2 Mixing EDTA & NaOCL experiment Extensive carious lesion Gingival bleeding Full gold crowns Dens case Lower second molar TF retreatment Coronal extension 2 separate palatal canals Lower canine Necrotic case Curved distal root Failing MTA