Fig. 2

Photomicrograph of H&E staining showing the subcutaneous tissue of control, ACTIVA, iRoot BP and MTA-HP after one- and two-weeks exposure. The 1st week, a control tube showing mild inflammatory reaction within and around the capsule, a1 the inset revealing thin capsule with minimal fibrinoid-like deposition infiltrated with few macrophages; b the opening of ACTIVA tube demonstrating moderate degree of inflammation (IR) with marked granulation tissue formation, b1 the inset showing infiltration of lymphocytes and macrophages and with marked fibroblastic activity (curved-arrow); c the iRoot BP tube showing intense inflammatory response, c1 the inset showing marked fibrosis and calcification within the inflammatory area (arrow); d MTA-HP tube showing moderate degree of inflammation, d1 the inset revealing mild inner necrosis associated with macrophages and lymphocytes infiltration. The 2nd week, e Control tube showing an obvious repair of the inflammatory capsule, e1 inset showing marked remodeling of the fibrous connective tissue (curved-arrow); f ACTIVA tube showing marked decrease of necrosis and inflammation f1 the inset showing ample amount of zigzag-like layers of elastic and collagen fibers (crossed-arrow); g iRoot BP tube showing thick capsule with still noticeable intense inflammation g1 the inset showing fibrosis, calcification (arrow) and multinuclear giant cells infiltration (arrowheads); h MTA HP tube showing relatively thick inflammatory capsule, h1 the inset showing leakage of some tube material associated with inflammatory cells infiltration with mild to moderate fibrosis and calcification (arrow). TO: Tube Opening, IR: Inflammatory Reaction, Bv: Blood vessel