Scanning and transmission electron microscopic studies of periapical lesions

Twenty chronic periapical granulomas and cysts and their corresponding teeth were examined using scanning and transmission electron microscopy, chronic periapical inflammation had caused root resorption which affected the cementum and dentin. However, root surface exposed to granulomas and cysts also indicated spontaneous cementum repair. At the periphery, cellular debris, fibroblasts, collagen fibrils, nerve bundles could be seen, which were continuations of the periodontal ligament. The surface topography of the superficial cells showed a reticular network of intercommunicating microridges surrounding micropits. Sometimes, they appeared disrupted with areas of exfoliation of the detached squamae. The transmission-electron microscopic findings revealed epithelial wide intercellular spaces, irregular base lamina, moderate numbers of inflammatory cells, increased rates of macrophages, edema, fibroblasts, enlarged and dilated blood vessels with extravasated RBCs and engulfed macrophages

Scanning electron microscopic study of visible light curing effects on the oral mucous membrane

The present investigation was undertaken on rats to demonstrate the structural changes that took place after the exposure of the gingiva to a dental visible light curing unit. Sixteen rats were irradiated and four were considered as controls. The mandibular right first molar was exposed to radiation for 40 seconds. The animals were classified into four groups [4 experimental and 1 control] and were sacrificed immediately, 2 days, 4 days and 2 weeks after exposure. Specimens were processed for ultrastructural and light microscopic investigations. The results indicate that emission from dental light curing units can affect the oral mucous membrane and may reduce its functional abilities

histologic and laboratory study of the oral mucosa under complete dentures using a modified acrylic resin

The present research was carried out to study the histologic as well as thehistochemical changes of the mucosa following the addition of polyvinylchloride to the heat cured acrylic resin denture bases. The amount ofchlorine release was also estimated. Biopsy specimens were taken from thecrest of the ridge from male patients just before and three months afterdenture insertion. The specimens were immediately fixed and processedaccordingly for histological and histochemical investigations. Changes in thedenture bearing oral mucosa following the addition of polyvinyl chloride tothe inserted dentures was of major interest, since mild to moderate cellularalterations occurred within the epithelium and underlying connective tissue. Traces of released chlorine from the dentures to the surrounding medium weredetected and estimated