ABSTRACT
This research aimed to obtain the depth dependence of polymerization contraction and microporosity from irradiated dental resin cements by X-ray computed microtomography (µCT). Samples (n = 5) of commercial Relyx U200 (RU) and AllCem Core (AC) dual-cure resin cements were injected in a cylindrical Teflon sampler (25 mm3 ) and separated according to polymerization mechanism: self-cured (not irradiated) and dual-cured (irradiated from the top surface with a LED device). The cement's volume was scanned with the µCT scanning conditions kept constant. To assess the depth dependence of polymerization contraction, it was measured the displacement of the cement mass from the sample holder at 30 vertical cuts (0.1 mm distant). To probe the microporosity, the percentage of area with presence of porosity by slice was obtained. All data were statistically treated. It was observed a positive linear correlation between depth and polymerization contraction in the irradiated groups. In the other hand, the concentration of micropores decreased with increasing depth. Furthermore, the composition of the resin cement was determinant for the correlation's coefficients of these physical properties with depth. The µCT technique showed to be useful to probe physical properties of dental restorative materials that influence in the clinical outcomes, revealing that, for thin specimens, when light cured the RU cement presented mechanical behavior more favorable for clinical applications.
Subject(s)
Polymerization , Resin Cements/analysis , X-Ray Microtomography , Hardness , Materials Testing , Porosity , Resin Cements/chemistry , Resin Cements/classificationABSTRACT
Metástases para o pâncreas são raras, podendo ocorrer a partir do carcinoma renal de células claras. Apresentamos um caso demetástase pancreática, envolvendo suprarrenal e hilo esplênico, em uma mulher de 49 anos, que teve carcinoma renal de células clarassete anos atrás. Em seguimento após nefrectomia, a paciente teve o diagnóstico de metástase em pâncreas, suprarrenal e hiloesplênico. Tratada com cirurgia e interferon. Imunohistoquímica para gp200 e CD-10, foi positiva. Tomografia computadorizada mostroumetástase para o estômago oito anos após a nefrectomia, estando a paciente em uso de interferon atualmente. Carcinoma de célulasrenais pode recidivar anos após a nefrectomia. Identificação e tratamento cirúrgico podem proporcionar suporte paliativo e sobrevidaem longo prazo.
Metastasis to the pancreas is uncommon; however, it may occur from clear renal cell carcinomas. We present a case of pancreaticmetastasis involving adrenal and splenic hilum in a 49 year-old woman that had clear renal cell carcinoma seven years ago. The patientin post nephrectomy follow-up presented a diagnosis of metastasis in the pancreas, adrenal and splenic hilus. The patients was treatedby surgery and interferon. Immunohistochemistry for gp200 and CD-10 was positive and computed tomography showed metastasis inthe stomach eight years after surgery. She is currently treated with interferon. Renal cell carcinoma can reappear years afternephrectomy, therefore, recognition and surgical treatment can provide palliation and long-term survival.
