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Publication
Caracterização química de um sistema adesivo universal "lowcost"
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Advisor(s)
Abstract(s)
Objetivos: Avaliar a composição química, as proporções dos principais componentes e a taxa de conversão de um sistema adesivo universal lowcost, através de espectroscopia de infravermelho transformada de Fourier (ATR-FTIR), comparando-o com o adesivo ScotchbondTM Universal® Plus.
Materiais e métodos: Foram selecionados dois sistemas adesivos universais: ScotchbondTM Universal® Plus e o Maxima Natural Elegance 7 Universal. A composição química foi avaliada através dos espectros obtidos por espectroscopia de ATR-FTIR em tempo real antes, durante e depois da fotopolimerização. Para cada adesivo foram realizadas 3 leituras (n = 3). As proporções dos componentes foram modeladas usando espectros de dois solventes (água e etanol), monómeros de metacrilato (HEMA, Bis-GMA, TEGMA, UDMA, 10-MDP e GPDM) e cargas. A carga e os espectros da mesma foram obtidos após a sua separação dos adesivos através de análise gravimétrica (n = 3). O ATR-FTIR foi utilizado para avaliar as taxas de conversão dos sistemas universais a 37 ºC com fotopolimerização de 20 s. A análise dos espectros resultantes e os respetivos cálculos dos parâmetros cinéticos foi realizado com recurso ao software Spectrum TimeBase v. 3.1.4. O tratamento estatístico dos dados foi realizado no programa SPSS (nível de significância de 5 %).
Resultados: A composição química do Maxima Natural Elegance 7 Universal difere do ScotchbondTM Universal® Plus, sendo que o adesivo lowcost apresenta 40 % de UDMA em vez de Bis-GMA. Ambos apresentam TEGMA, HEMA, 10-MDP, água e etanol. Relativamente à percentagem de partículas de carga e a taxa de conversão não se verificaram diferenças (t-test, p > 0,05). A taxa de conversão do ScotchbondTM Universal® Plus é de 67 % e do adesivo lowcost 48 %.
Conclusões: O sistema adesivo universal lowcost difere do ScotchbondTM Universal® Plus, no entanto apresenta monómeros funcionais e pode vir a ter aplicabilidade clínica.
Objectives: Evaluate the chemical composition, ratios of main components and degree of conversion of a lowcost universal adhesive system, using Attenuated Total Reflectance Fourier Transform Infra-red Spectroscopy (ATR-FTIR), comparing it with ScotchbondTM Universal® Plus. Materials and methods: Two universal adhesive systems were tested: ScotchbondTM Universal® Plus (SBU) and Maxima Natural Elegance 7 Universal (NEU). The chemical composition was evaluated using the spectra obtained by real-time ATR-FTIR spectroscopy before, during and after photopolymerization. For each sticker, 3 readings were taken (n = 3). Component proportions were modeled using spectra of two solvents (water and ethanol), methacrylate monomers (HEMA, Bis-GMA, TEGMA, UDMA, 10-MDP and GPDM) and fillers. Its charge and spectra were obtained after separation from the adhesives using gravimetric analysis (n = 3). ATR-FTIR was used to evaluate the rates of universal systems at 37 ºC with 20 s photopolymerization. The analysis of the resulting spectra and the respective calculations of kinetic parameters were performed using the Spectrum TimeBase v software. 3.1.4. The statistical treatment of the data was carried out using the SPSS program (significance level of 5 %). Results: The chemical composition of Maxima Natural Elegance 7 Universal differs from ScotchbondTM Universal® Plus, with the lowcost adhesive containing 40 % UDMA instead of Bis-GMA. Both feature TEGMA, HEMA, 10-MDP, water and ethanol. Regarding the percentage of filler particles and the conversion rate, there were no differences (t-test, p > 0.05). The conversion rate for the ScotchbondTM Universal® Plus is 67 % and for the lowcost adhesive is 48 %. Conclusions: The low-cost universal adhesive system differs from ScotchbondTM Universal® Plus, but it has functional monomers and may have clinical applicability.
Objectives: Evaluate the chemical composition, ratios of main components and degree of conversion of a lowcost universal adhesive system, using Attenuated Total Reflectance Fourier Transform Infra-red Spectroscopy (ATR-FTIR), comparing it with ScotchbondTM Universal® Plus. Materials and methods: Two universal adhesive systems were tested: ScotchbondTM Universal® Plus (SBU) and Maxima Natural Elegance 7 Universal (NEU). The chemical composition was evaluated using the spectra obtained by real-time ATR-FTIR spectroscopy before, during and after photopolymerization. For each sticker, 3 readings were taken (n = 3). Component proportions were modeled using spectra of two solvents (water and ethanol), methacrylate monomers (HEMA, Bis-GMA, TEGMA, UDMA, 10-MDP and GPDM) and fillers. Its charge and spectra were obtained after separation from the adhesives using gravimetric analysis (n = 3). ATR-FTIR was used to evaluate the rates of universal systems at 37 ºC with 20 s photopolymerization. The analysis of the resulting spectra and the respective calculations of kinetic parameters were performed using the Spectrum TimeBase v software. 3.1.4. The statistical treatment of the data was carried out using the SPSS program (significance level of 5 %). Results: The chemical composition of Maxima Natural Elegance 7 Universal differs from ScotchbondTM Universal® Plus, with the lowcost adhesive containing 40 % UDMA instead of Bis-GMA. Both feature TEGMA, HEMA, 10-MDP, water and ethanol. Regarding the percentage of filler particles and the conversion rate, there were no differences (t-test, p > 0.05). The conversion rate for the ScotchbondTM Universal® Plus is 67 % and for the lowcost adhesive is 48 %. Conclusions: The low-cost universal adhesive system differs from ScotchbondTM Universal® Plus, but it has functional monomers and may have clinical applicability.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Adesão Monómeros funcionais FTIR Composição química