Localized Cutaneous Argyria Mimicking Blue Nevus after Wearing Earrings

Localized cutaneous argyria is a rare condition in which the skin changes into blue-grey spots due to the absorption of silver. The lesions need to be differentiated from other pigmentary disorders and require radiographic and histological examination for more accurate diagnosis. Scanning electron microscopy and energy dispersive x-ray spectroscopy can be a confirmatory tool in the evaluation of silver elements in biopsy tissue. This report shows the localized cutaneous argyria in earlobe of a 21-year-old woman who wears silver earrings for 10 years.

Molecular and morphological surface analysis: effect of filling pastes and cleaning agents on root dentin

Abstract The quality of the dentin root is the most important factor for restoration resin sealing and drives the outcome of endodontic treatment. Objective This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman), micro energy-dispersive X-ray fluorescence (µ-EDXRF) and scanning electron microscopic (SEM) analysis. Material and Methods Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP), Calen®+zinc oxide (CZ), Calcipex II® (CII), Vitapex® (V). After seven days, filling paste groups were distributed to 4 subgroups according to cleaning agents (n=5): Control-no cleaning (C), Ethanol (E), Tergenform® (T), 35% Phosphoric acid (PA). Then, the roots were sectioned and the dentin root sections were internally evaluated by FT-Raman, µ-EDXRF and SEM. Data was submitted to two-way ANOVA and Tukey tests (α=0.05). Results Regarding filling pastes, there was no significant difference in organic content. CP provided the lowest calcium values and, calcium/phosphoric ratio (Ca/P), and the highest phosphoric values. For cleaning agents there was no difference in organic content when compared to the C; however, T showed significantly higher calcium and Ca/P than PA. All groups showed similar results for phosphorus. The dentin smear layer was present after use of the cleaning agents, except PA. Conclusion The filling pastes changed the inorganic content, however they did not change the organic content. Cleaning agents did not alter the inorganic and organic content. PA cleaned and opened dentin tubules.

In Vitro Microstructural Analysis of Dental Implants Subjected to Insertion Torque and Pullout Test

The change in the implant microstructure during handling may reduce the potential of surface treatment on the osteoinduction and, therefore, on the osseointegration. The aim of this study was to evaluate by energy-dispersive X-ray spectroscopy (EDX) the effect of insertion torque and pullout test on the microstructure of dental implants with different shapes. Four shapes of implants (n=8) were selected: conical with surface treatment (COTS), cylindrical with surface treatment (CTS), cylindrical with double surface treatment (CTSD) and cylindrical with machined surface (CSU). Before and after performing the mechanical tests, the screw surfaces were subjected to analysis of chemical composition by EDX. The results obtained by the microstructural analysis showed presence of three main chemical elements: Ti, C and O. There was a significant change in the concentration of Ti and C. The implant with double surface treatment (CTSD) showed the greatest Ti reduction and the greatest C increase. It may be concluded that the mechanical manipulation may alter the implant surfaces as regards their microstructure. Therefore, surgical planning should take into consideration the choice of surface treatment because the characteristics of the implants may be modified as they are inserted and removed from the bone site.

A alteração da microestrutura do implante durante seu manuseio pode reduzir o potencial do tratamento superfícial na osteoindução e consequentemente na osseointegração. O objetivo deste estudo foi avaliar o efeito do torque de inserção e do ensaio de arrancamento, na microestrutura de implantes odontológicos de diferentes formatos, por meio de espectometria de energia dispersiva de raios-X (EDS). Para a realização do estudo foram selecionados quatro modelos de implantes Conexão(r) (n=8): Cônico com tratamento de superfície (COTS), Cilíndrico com tratamento de superfície (CTS), Cilíndrico com duplo tratamento de superfície (CTSD) e Cilíndrico com superfície usinada (CSU). Antes e após a realização dos ensaios mecânicos, os parafusos foram submetidos à análise da composição química de suas superfícies, por meio de EDS. Os resultados obtidos com a análise microestrutural demonstraram a presença de três elementos químicos principais: Ti, C e O. Foi verificada alteração estatisticamente significante na concentração dos elementos Ti e C. O implante com duplo tratamento de superfície (CTSD) foi o que apresentou a maior redução do Ti e maior aumento do C. A partir dos dados obtidos foi possível concluir que a manipulação mecânica pode alterar a superfície dos implantes quanto à sua microestrutura. Sendo assim, o planejamento cirúrgico deve levar em conta a escolha do tratamento de superfície, pois uma vez que o implante é inserido e removido do leito ósseo suas características podem ser alteradas.