engleski

Histopathological analysis of therapy-resistant periapical lesions

The intra- and extraradicular infections, foreign body reaction and genuine cysts are often associated with a failure of endodontic therapy. The purpose of this study was to evaluate the histopathological and microbial properties of therapy-resistant periapical lesions that persisted after properly performed endodontic procedures. Periapical lesions were removed as block biopsies during aseptic surgical treatment of the affected teeth, and were immediately immersed in 10% neutral buffered formalin. The fixed specimens were routinely processed, paraplast embedded, sectioned at 3 *m and stained with haematoxylin and eosin, PAS, and Gram stain to recognize the presence and location of microorganisms and inflamatory cells. The demineralization was performed using the standard decalcifier (Shandon Scientific, Runcorn, UK) for 8 days, daily incubated for 6 h at 60oC. The specimens were examined by light microscopy. The histopathological evaluation of 35 specimens revealed four radicular cysts, nine cystic apical granulomas, and periapical tissue in different stages of chronic inflammation. Seven samples showed foreign body fragments, and three showed haemosiderin granules. Four samples showed thermal injury, probably caused by overheating during apicectomy. In two cases staining revealed the presence of fungi and in two others Gram-negative cocci were found.

periapical lesions; histhopathology

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