Fig. 5
Upper panel [A]: Representative sample for positive control group showing CBCT analysis and photomicrographs of dog’s positive control (intact tooth) sample (a) Digital radiograph showing intact tooth. (b) Coronal view of CBCT image showing pulp space with no calcific tissues and normal periapical area. (c) Sagittal view of CBCT image showing positive control tooth with normal periapical area. (d&d*) Horizontal cuts of CBCT image showing middle and apical thirds of the root, respectively. Notice the absence of calcific tissues in normal canal space. (e) Photomicrograph showing normal periapical area (f) Positive control sample showing layers of normal pulp tissue; odontoblastic layer, cell-free zone, cell -rich zone and core of the pulp. (g&h) Same sample at higher magnification showing odontoblastic layer “black arrows” and highly vascularized normal pulp tissue with numerous blood vessels “red arrows”. (H&E: e, f, g& h); (10x: e. 40x: f, 400x: g & h). Lower panel [B]: Representative sample for negative control group showing CBCT analysis and photomicrographs of dog’s negative control (infected tooth) sample (i) Digital radiograph showing infected tooth 3 months following the access opening. (j) Sagittal view of CBCT image showing negative control tooth with large periapical lesion. (k) Coronal view of CBCT image showing pulp space with no calcific tissues and large periapical lesion. (l&l*) Horizontal cuts of CBCT image showing middle and apical thirds of the root, respectively. Notice the absence of calcific tissues in the canal space. (m) Photomicrograph showing canal space with no de-novo tissue regeneration and signs of severe root resorption and periapical inflammation. (n) Degenerated pulp tissue “green arrow heads”, multiple resorptive lacunae “black arrow heads” and severe inflammation. (o) Numerous inflammatory cells at the periapical area. (H&E: m, n &o); (10x: m, 40x: n 400x: o)