97 research outputs found

    Group-IV graphene- and graphane-like nanosheets

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    We performed a first principles investigation on the structural and electronic properties of group-IV (C, SiC, Si, Ge, and Sn) graphene-like sheets in flat and buckled configurations and the respective hydrogenated or fluorinated graphane-like ones. The analysis on the energetics, associated with the formation of those structures, showed that fluorinated graphane-like sheets are very stable, and should be easily synthesized in laboratory. We also studied the changes on the properties of the graphene-like sheets, as result of hydrogenation or fluorination. The interatomic distances in those graphane-like sheets are consistent with the respective crystalline ones, a property that may facilitate integration of those sheets within three-dimensional nanodevices

    The importance of Cone-Beam computed tomography in diagnosis of associated mandibular osteonecrosis: case report / A importância da TCFC no diagnóstico e prognóstico da osteonecrose mandibular associada aos bisfosfonatos: relato de caso clínico

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    The Cone-Beam Computed Tomography (CBCT) is very useful in diagnosis and treatment planning, as well as in the prognosis of osteonecrosis of the jaws. This study reports a clinical case of Bisphosphonate-Associated Mandibular Osteonecrosis from the perspective of CBCT. The patient, female, 83 years old, presented painful symptoms in the posterior region of the right mandible and reported Bisphosphonate medication for more than five years to treat osteoporosis and osteopenia. Based on clinical and CBCT imaging characteristics, the patient was diagnosed with Bisphosphonate-Associated Mandibular Osteonecrosis. Initially, the treatment consisted of oral antibiotic therapy, pain control, hyperbaric oxygenation and oral hygiene (mouthwashes). After 11 months of clinical therapy, CBCT revealed bone reconstruction of the buccal cortex, but also a hypodense imaging in the lingual cortex compatible with bone lysis and bone sequestration. The patient was referred for bone debridement and sequestrectomy. The histopathological diagnosis consisted of osteonecrosis with secondary acute osteomyelitis. After 60 days of the surgical procedure and hyperbaric sessions/systemic antibiotic therapy, an oral healthy mucosa in the region of the right mandibular body was evidenced in the intraoral examination. Cortical bone regeneration was observed on CBCT. Concluded that the use of CBCT, in this case report, makes it possible to estimate the extent of the lesion and the post-treatment outcome, assessing bone density, the presence of bone sequestration and the involvement of the involved areas. In fact, early diagnosis is essential for the success of the therapeutic approach
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