COR NA ODONTOLOGIA RESTAURADORA MODERNA: REVISÃO DE LITERATURA

A seleção de cor e a aparência dos dentes são fenômenos complexos, que exigem preparo e domínio do cirurgião-dentista e do técnico em prótese o qual realiza os trabalhos laboratoriais, como restaurações indiretas. Nesse momento qualquer interferência entre esses profissionais pode ocasionar em drástica diferença na tomada de cor e a interpretação pode ser altamente subjetiva e dependente de diversos fatores. A seleção da cor do dente artificial é um processo determinante para a aceitação do tratamento pelo paciente, pois a mídia exerce grande influência sobre a opinião da população, exibindo sorrisos extremamente brancos, o que interfere, muitas vezes, no padrão de estética/e ou beleza exigidos pelos pacientes. O objetivo deste estudo foi apresentar através de uma revisão de literatura, os aspectos que determinam a cor de um elemento dental e que estes simplifiquem e estabeleçam uma sintonia entre o consultório e o laboratório de prótese, pois a incompatibilidade de cor de uma restauração com o dente natural pode não contentar tanto o dentista quanto o  paciente, podendo levar à necessidade de substituição, o que demanda tempo e custo adicionais.PALAVRAS-CHAVE: Resina composta; Cerâmica odontológica; Estética

Direct Determination of Malachite Green and Leucomalachite Green in Natural Waters by Exploiting Solid-phase Sorption and Digital Image

Although malachite green (MG), a triphenylmethane dye, is banned for use in aquaculture in several countries, it is still widely employed to treat infections in fish and fish eggs. In living organisms, it is reduced to leucomalachite green (LMG) during physiological processes and can accumulate in adipose tissue. This work describes the development and verification of a simple and portable method, using preconcentration on an adsorbent surface and digital image analysis, for the determination of malachite green and leucomalachite green in natural waters. The optimum conditions of production and extraction in the film were evaluated univariate and the images were analyzed with the aid of Image J. The analytical curves were obtained from each color channel, using multiple linear regression (MLR) models for all parameters of the RGB system. Malachite green was adsorbed on a Florisil surface, followed by quantification using a calibration curve obtained with RGB image parameters, with the preconcentration factor was close to 10.  Accuracy was assessed using recovery tests on river natural waters samples, showing no significant matrix effect or additive error. The technique is suitable for environmental monitoring purposes. Simple method, practical and versatile. DOI: http://dx.doi.org/10.17807/orbital.v12i4.149

Direct Determination of Malachite Green and Leucomalachite Green in Natural Waters by Exploiting Solid-phase Sorption and Digital Image

Although malachite green (MG), a triphenylmethane dye, is banned for use in aquaculture in several countries, it is still widely employed to treat infections in fish and fish eggs. In living organisms, it is reduced to leucomalachite green (LMG) during physiological processes and can accumulate in adipose tissue. This work describes the development and verification of a simple and portable method, using preconcentration on an adsorbent surface and digital image analysis, for the determination of malachite green and leucomalachite green in natural waters. The optimum conditions of production and extraction in the film were evaluated univariate and the images were analyzed with the aid of Image J. The analytical curves were obtained from each color channel, using multiple linear regression (MLR) models for all parameters of the RGB system. Malachite green was adsorbed on a Florisil surface, followed by quantification using a calibration curve obtained with RGB image parameters, with the preconcentration factor was close to 10.  Accuracy was assessed using recovery tests on river natural waters samples, showing no significant matrix effect or additive error. The technique is suitable for environmental monitoring purposes. Simple method, practical and versatile. DOI: http://dx.doi.org/10.17807/orbital.v12i4.149