An In Vitro Pilot Study on the Effects of Silver Diamine Fluoride on Periodontal Pathogens and Three-Dimensional Scaffolds of Human Fibroblasts and Epithelial Cells

Figure 5

TUNEL staining for apoptotic cells. The following annotation abbreviations are used: acellular collagen (AC), cellular collagen (CC), connective tissue (CT), basal layer (B), spinosum (S), granular (G), keratin (K). Apoptosis of keratinocytes and fibroblasts in HSE was assessed with TUNEL staining—apoptotic cells nuclei will stain with dark (a) Control untreated construct shows minimal apoptosis occurring among fibroblasts in the most superficial region of the connective tissue; no epithelial cells stained for apoptosis. (b) 12 hours: Apoptotic cells noted throughout all nucleated layers of the epithelium and within the underlying connective tissue. (c) 24 hours: Missing epithelial layer lost during processing, but fibroblasts staining for apoptosis are limited to first few layers of connective tissue. (d) 3 days: Basal and suprabasal layers of epithelium are adherent to keratinized layer above and all stain dark for apoptosis along with superficial layer of connective tissue. (e) 5 days: Fibroblasts stain for apoptosis throughout all regions of connective tissue (f) 10 days: Fewer apoptotic cells that are limited to the first few cell layers of connective tissues. (Scale bar = 50 μm).