RESUMO
In this paper, we present an alternative technique for the removal of Brilliant Green dye (BG) in aqueous solutions based on the application of molecularly imprinted polymer (MIP) as a selective adsorbent for BG. The MIP was prepared by bulk radical polymerization using BG as the template; methacrylic acid (MAA) as the functional monomer, selected via computer simulations; ethylene glycol dimethacrylate (EGDMA) as cross-linker; and 2,2'-azobis(2-methylpropionitrile) (AIBN) as the radical initiator. Scanning electron microscopy (SEM) analyses of the MIP and non-molecularly imprinted polymer (NIP)-used as the control material-showed that the two polymers exhibited similar morphology in terms of shape and size; however, N2 sorption studies showed that the MIP displayed a much higher BET surface (three times bigger) compared to the NIP, which is clearly indicative of the adequate formation of porosity in the former. The data obtained from FTIR analysis indicated the successful formation of imprinted polymer based on the experimental procedure applied. Kinetic adsorption studies revealed that the data fitted quite well with a pseudo-second order kinetic model. The BG adsorption isotherm was effectively described by the Langmuir isotherm model. The proposed MIP exhibited high selectivity toward BG in the presence of other interfering dyes due to the presence of specific recognition sites (IF = 2.53) on its high specific surface area (112 m2/g). The imprinted polymer also displayed a great potential when applied for the selective removal of BG in real river water samples, with recovery ranging from 99 to 101%.
RESUMO
Increasing prevalence of erosive tooth wear (ETW) is notable mainly due to current knowledge and its early diagnosis. Once teeth are functionally and/or esthetically affected, dental restorations may become necessary. Materials capable of interacting with the eroded dental tissue allied to their resistance to subsequent continuous erosive challenges are desirable. Giomer technology based on S-PRG (surface pre-reactive glass) filler has been launching to provide benefits for the dental treatment due to its innovative multi-ionic release system, which involves fluoride. This case report describes the employment of preventive and restorative materials based on this technology for a patient under frequent erosive challenges and complaining about dental sensitivity. Patient reported immediate reduction on this sensitivity and the restorations has been followed up for 2 years, presenting satisfactory performance. S-PRG-based systems seem to be promissory for preventive and therapeutic management of ETW used simultaneously with the patient compliance. (AU)
O aumento da prevalência do desgaste dentário erosivo (DDE) é notável especialmente devido ao conhecimento atual e seu diagnóstico precoce. Uma vez que os dentes são afetados funcional e/ou esteticamente, restaurações dentárias se tornam necessárias. Materiais focados na habilidade de interagir com o tecido dentário erodido associados com sua resistência aos desafios erosivos contínuos subsequentes são desejáveis. A tecnologia Giomer baseada em partículas S-PRG (superfície de vidro pré-reativo) foi lançada no mercado para oferecer benefícios para o tratamento odontológico devido ao seu sistema inovador de liberação multi-iônica, que envolve o flúor. Esse caso clínico descreve o uso de materiais preventivo e restaurador baseados nessa tecnologia em um paciente em desafio erosivo e com queixa de sensibilidade. O paciente relatou redução imediata da sensibilidade e as restaurações foram acompanhadas por 2 anos apresentando desempenho satisfatório. Sistemas baseados em S-PRG se mostram promissores para manejo preventivo e terapêutico do DDE empregados simultaneamente à colaboração do paciente.(AU)