Iodine penetration and glycogen distribution in vital staining of oral mucosa with iodine solution

Objective To assess and compare iodine penetration and glycogen distribution in a vital staining of oral mucosa with iodine solution. Study Design Twenty samples were obtained including both iodine-stained and -unstained mucosa. Intraepithelial iodine was examined using frozen sections. Glycogen distribution was assessed by periodic acid–Schiff staining and transmission electron microscopy. Results Iodine accumulation was observed mainly superficially and in the upper and middle thirds of prickle cell layers, with glycogen in almost the whole epithelium except for the para- and basal cell layers. The pattern of iodine and glycogen distribution was classified into 3 types (full-, surround-, and scatter-type). The iodine color was mainly derived from the cells with full- and surround-type distributed glycogen in the upper half of the oral epithelium. Conclusions The results of this study suggested that iodine penetrated into nonkeratinized oral epithelium and reacted mainly with intraepithelial glycogen homogeneously distributed in the cytoplasm.