Weight-loss and surface roughness of enamel after microabrasion procedure with different agents / Perda de peso e rugosidade da superfície do esmalte após procedimento de microabrasão com diferentes agentes

Introduction: Enamel microabrasion is achieved by abrasion of the enamel surface and it is a quick, practical and efficient procedure. Objective It was assessed the weight loss and surface aspect of enamel after microabrasion procedures with commercial and mixtures made in-office. Material and method Eighty bovine incisors were divided into four groups (n=10): OpalustreTM (6.6% HCl + silicon carbide); Whiteness RMTM (6% HCl + silicon carbide); 37% H3PO4 + pumice and 10% HCl + pumice. Treatment was performed by 15 applications of 10s duration. The enamel weight loss was determined by the difference in weight before and after the microabrasion. The surfaces were analyzed by a surface roughness equipment and scanning electron microscopy. Data were submitted to paired-T test, one-way ANOVA and Tukey tests (α=0.05). Result It was observed significantly weight loss for all groups. The difference in weight loss ranged from 0.037±0.012 for group 37% H3PO4 and from 0.054±0.009 for group 6,6% HCl. There was a significant increase in surface roughness for all groups and 10% HCl group showed the lower results (0.65±0.09). It was observed different patterns of enamel morphology by SEM images. Conclusion The in-office mixtures resulted in the lowest enamel structure loss (37% H3PO4) and the lowest surface roughness (10% HCl).

Introdução: A microabrasão do esmalte é realizada através da abrasão da superfície do mesmo, apresentando-se como um procedimento rápido, prático e eficiente. Objetivo Avaliar a perda de peso e o aspecto superficial do esmalte após procedimentos de microabrasão com agentes comerciais e não comerciais. Material e método Oitenta incisivos bovinos foram divididos em quatro grupos (n = 10): OpalustreTM (6,6% HCl + carboneto de silício); Whiteness RMTM (6% HCl + carboneto de silício); 37% H3PO4 + pedra-pomes e 10% HCl + pedra-pomes. O tratamento foi realizado em 15 aplicações de 10s de duração. A perda de peso do esmalte foi determinada pela diferença de peso antes e depois da microabrasão. As superfícies foram analisadas por equipamento de rugosidade superficial e microscopia eletrônica de varredura. Os dados foram submetidos ao teste T-pareado, ANOVA one-way e teste de Tukey (α = 0,05). Resultado Foi observada perda de peso significativa para todos os grupos, a diferença na perda de peso variou de -0,037±0,012 para o grupo 37% H3PO4 a -0.054±0.009 para o grupo 6.6% HCl. Houve um aumento significativo na rugosidade da superfície para todos os grupos e o grupo 10%HCl apresentou os resultados mais baixos (0,65±0,09). Foram observados diferentes padrões de morfologia do esmalte por meio de imagens MEV. Conclusão Os agentes não comerciais resultaram na menor perda de estrutura do esmalte (37% H3PO4) e na rugosidade superficial (10% HCl).

Polymer-based surface plasmon resonance biochip: construction and experimental aspects

Abstract Introduction: Surface plasmon resonance biosensors are high sensitive analytical instruments that normally employ glass materials at the optical substrate layer. However, the use of polymer-based substrates is increasing in the last years due to favorable features, like: disposability, ease to construction and low-cost design. Review Recently, a polymer-based SPR biochip was proposed by using monochromatic and polychromatic input sources. Its construction and experimental considerations are detailed here. Experimental considerations and results, aspects from performance characteristics (resonance parameters, sensitivity and full width at half maximum – FWHM – calculations) are presented for hydrophilic and hydrophobic solutions. It is included also a brief description of the state of the art of polymer-based SPR biosensors.