Search PubMed⌕ Search

Biomedical subjects

A Braun

Publications and source records attributed to A Braun.

219 records · Page 13Linked to original sources
PubMedDate not supplied

Evaluation of selective caries removal by a fluorescence feedback-controlled Er:YAG laser in vitro.

AIM: To establish a fluorescence threshold level that could guide a therapeutic Er:YAG laser through a caries lesion to determine a therapeutic endpoint of caries removal. MATERIALS AND METHODS: A total of 65 extracted human teeth, 35 with dentine caries and 30 healthy, were used for this study. An Er:YAG laser system that emitted at a wavelength of 2.94 microm was used. The laser was equipped with a laser fluorescence feedback system, excitation wavelength 655 nm, to control the irradiation by the Er:YAG laser. The evaluated threshold levels of the fluorescence feedback system were 3, 7, 8, 10, 12, 15 and 20. After treatment the teeth were prepared for histological staining according to the method of Brown and Brenn for the identification of bacteria. The specimens were subjected to a quantitative evaluation of residual bacteria on the treated dentine surface. In addition, the internal fluorescence of dentine and potential fluorescence changes of dentine after laser irradiation were evaluated. RESULTS: About 80% of the irradiated dentine surface showed residual bacteria with threshold levels of 20, 15, 12, and 10. Residual bacteria were not found with threshold levels of 7 and 3. The study revealed a significant increase in dentine fluorescence after laser irradiation. CONCLUSION: The results of the present in vitro study indicate that a fluorescence threshold level of 7 or 8 units can guide an Er:YAG laser to a complete removal of carious dentine.

Aluminum↗
PubMedDate not supplied

Meningioma metastatic to thyroid gland.

OBJECTIVE: To describe the first reported case of meningioma metastasizing to and completely infiltrating the thyroid gland. METHODS: We present a detailed case report, including radiographic, histologic, and immunostaining findings, in a patient with an atypical meningioma who had a progressively enlarging thyroid mass that proved to be a metastatic meningioma. RESULTS: A 49-year-old man had a meningioma in the parieto-occipital region that had spread locally to the scalp and bone by the time of surgical resection. Local recurrence during the following year prompted repeated surgical resection, tumor embolization, radiotherapy, and chemotherapy. Despite aggressive therapy, the tumor progressed. A thyroid mass was first noted 2 years after the meningioma was diagnosed. Enlargement of the mass caused airway obstruction, necessitating an emergency thyroidectomy. Histologic examination of the thyroidectomy specimen showed that the thyroid gland had been extensively replaced by metastatic meningioma. CONCLUSION: To our knowledge, this is the first reported case of metastatic meningioma extensively infiltrating the thyroid gland. This case report expands the spectrum of tumors that metastasize to the thyroid gland.

Antineoplastic Agents↗