Ex Vivo Assessment of Photodynamic Therapy in Achieving Microbial Reduction.

The study was to assess the effects of photodynamic therapy (PDT) on root canals contaminated by Enterococcus faecalis (E. faecalis). PDT was performed with 0.005% methylene blue dye and with a low-intensity red emission laser. Microbiological samples were collected before, immediately and 72 hours after instrumentation. Although PDT performed with the chosen light parameters promoted additional microbial reduction, this therapy did not achieve a statistically significant reduction of E. faecalis.

Cell proliferation and apoptosis in keratocystic odontogenic tumors

Objectives: Keratocystic odontogenic tumors (KOTs), also known as odontogenic keratocysts, were recently classifiedas a benign neoplasia due to the aggressive clinical behavior. Although several studies have shown the high proliferativeactivity of the epithelial lining, few studies have evaluated apoptosis in KOTs. Therefore, the aim of this study isto evaluate and compare the proliferation index (PI) and the apoptotic index (AI) of the epithelial lining in sporadicKOTs, KOTs associated with the Nevoid Basal Cell Carcinoma Syndrome (NBCCS KOTs), and dentigerous cysts.Material and methods: A total of 11 sporadic KOTs, 15 NBCCS KOTs, and 11 dentigerous cysts were evaluated. ThePI was assessed by immunohistochemical detection of the cell proliferation marker Ki-67. The AI was assessed bymorphological evaluation of sections stained by methyl green-pyronin. The TUNEL assay was used to confirm theoccurrence of apoptosis. Differences in the PI and the AI between sporadic KOTs, NBCCS KOTs, and dentigerouscysts were analyzed using the Kruskal-Wallis test. Differences in the PI and the AI between the epithelial layers ofeach lesion were analyzed using the Wilcoxon test.Results: The PI and AI were higher in sporadic and NBCCS KOTs than in dentigerous cysts. No difference in theseindexes was observed between sporadic and NBCCS KOTs. In dentigerous cysts, the PI was higher in the basal layer.In sporadic and NBCCS KOTs, the PI was higher in suprabasal layer. No difference in the AI was observed betweenthe basal layer and the suprabasal layer in the three lesions. The AI was higher in the superficial layer of sporadicand NBCCS KOTs.Conclusions: The present study demonstrates that the epithelial lining of KOTs shows a distinct pattern of cell proliferationand apoptosis, reflecting its high cell turnover and reinforcing its classification as an odontogenic tumor (AU)

Advanced osteosarcoma of the maxilla: A case report

No disponible

Osteosarcomas are primary malignant bone tumours in which mesenchymal cells produce osteoid. It is generallythe most common malignant bone neoplasm, although lesions of the jaw are uncommon. Osteosarcoma of the jaw(JOS) presents a lower incidence of metastasis and a better prognosis than osteosarcoma of the long bones. However, patients with JOS can exhibit advanced tumours, mainly when early diagnosis is not performed. This article reports on a case of an advanced osteosarcoma of the maxilla. A 38-year-old woman was referred for evaluation and treatment of recurrent fibrous dysplasia of the facial bones. The patient related that she had been diagnosed with fibrous dysplasia four years earlier and, since the first diagnosis, she was submitted to four surgical interventions, all followed by recurrences. The main clinical findings were redness and swelling of the facial skin, upper lip ulceration,and hard palate swelling. Computed tomography showed a large hyperdense mass in right maxilla extending to rightorbit and left maxillary sinus. An incisional biopsy was performed and microscopic examination showed areas ofosteoid and chondroid formation surrounded by a cellular stroma. The diagnosis of osteosarcoma was establishedand the patient was recommended for oncologic treatment. Unfortunately, she died six months after the diagnosisdue to uncontrollable local spread (AU)