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Análise microscópica da libertação de microplásticos por alinhadores ortodônticos transparentes
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Objetivos: Este estudo teve como objetivo analisar microscopicamente os microplásticos que foram libertados pelos aparelhos ortodônticos transparentes quando expostos a diferentes bebidas de consumo frequente. Pretendeu-se determinar se o pH e a composição química da bebida influenciam a degradação do polímero e a consequente libertação de partículas microscópicas.
Materiais e Métodos: Foram utilizados 12 pares de alinhadores ortodônticos transparentes clinicamente não utilizados, divididos em quatro grupos experimentais (n=3/bebida), em primeiro temos o grupo controlo (saliva artificial) e depois foram expostos a Água Monchique®, Chá Preto e Cerveja SuperBock®. A metodologia a aplicar no tratamento da amostra, consiste em ciclos diários com períodos de agitação constante de 2 horas (na presença do agente em estudo) e de repouso em saliva artificial (durante 22 horas) a 37ºC e durante 7 dias. As partículas libertadas durante o tratamento serão recuperadas por filtração a vácuo, utilizando membranas de acetato de celulose. Seguidamente será realizada uma análise por lupa estereoscópica e por microscopia de fluorescência que se pretende que inclua uma caracterização morfológica detalhada das partículas, bem como a sua quantificação.
Resultados: Verificou-se a libertação de partículas compatíveis com microplásticos em todas as condições. As contagens foram aumentando conforme a acidez da bebida e da sua complexidade química: Grupo controlo- 7 partículas; Água Monchique® - 10 partículas; Chá Preto - 21 partículas e Cerveja SuperBock®– 25 partículas. As partículas apresentavam bordos irregulares e superfícies rugosas, indicativas de fragmentação e degradação. As análises em FTIR confirmaram a presença de bandas características do material polimérico.
Conclusões: Os alinhadores ortodônticos transparentes libertam microplásticos após períodos de exposição. As bebidas ácidas, gaseificadas e alcoólicas intensificam a degradação do material enquanto meios alcalinos apesar de também haver degradação apresentam um efeito mais moderado. Estes resultados reforçam a importância de cumprir as recomendações clínicas que aconselham remover os alinhadores ao consumir bebidas, prevenindo a degradação do material e potenciais riscos biológicos.
Aims: This study aimed to microscopically analyze the microplastics released by clear orthodontic appliances when exposed to different frequently consumed beverages. The objective was to determine whether the pH and chemical composition of the beverage influence polymer degradation and the consequent release of microscopic particles. Materials and Methods: Twelve pairs of clinically unused clear orthodontic aligners were used, divided into four experimental groups (n=3/beverage). First, we had the control group (artificial saliva), and then they were exposed to Monchique® Water, Black Tea, and SuperBock® Beer. The methodology applied to the sample treatment consists of daily cycles with periods of constant agitation for 2 hours (in the presence of the agent under study) and rest in artificial saliva (for 22 hours) at 37ºC for 7 days. The particles released during treatment will be recovered by vacuum filtration using cellulose acetate membranes. This will be followed by analysis using a stereoscopic magnifying glass and fluorescence microscopy, which is intended to include a detailed morphological characterization of the particles, as well as their quantification. Results: The release of particles compatible with microplastics was verified under all conditions. The counts increased according to the acidity of the beverage and its chemical complexity: Control group - 7 particles; Monchique® Water - 10 particles; Black Tea - 21 particles; and SuperBock® Beer - 25 particles. The particles had irregular edges and rough surfaces, indicative of fragmentation and degradation. FTIR analyses confirmed the presence of bands characteristic of polymeric material. Conclusions: Clear orthodontic aligners release microplastics after periods of exposure. Acidic, carbonated, and alcoholic beverages intensify the degradation of the material, while alkaline media, although also causing degradation, have a more moderate effect. These results reinforce the importance of complying with clinical recommendations to remove aligners when consuming beverages, preventing material degradation and potential biological risks.
Aims: This study aimed to microscopically analyze the microplastics released by clear orthodontic appliances when exposed to different frequently consumed beverages. The objective was to determine whether the pH and chemical composition of the beverage influence polymer degradation and the consequent release of microscopic particles. Materials and Methods: Twelve pairs of clinically unused clear orthodontic aligners were used, divided into four experimental groups (n=3/beverage). First, we had the control group (artificial saliva), and then they were exposed to Monchique® Water, Black Tea, and SuperBock® Beer. The methodology applied to the sample treatment consists of daily cycles with periods of constant agitation for 2 hours (in the presence of the agent under study) and rest in artificial saliva (for 22 hours) at 37ºC for 7 days. The particles released during treatment will be recovered by vacuum filtration using cellulose acetate membranes. This will be followed by analysis using a stereoscopic magnifying glass and fluorescence microscopy, which is intended to include a detailed morphological characterization of the particles, as well as their quantification. Results: The release of particles compatible with microplastics was verified under all conditions. The counts increased according to the acidity of the beverage and its chemical complexity: Control group - 7 particles; Monchique® Water - 10 particles; Black Tea - 21 particles; and SuperBock® Beer - 25 particles. The particles had irregular edges and rough surfaces, indicative of fragmentation and degradation. FTIR analyses confirmed the presence of bands characteristic of polymeric material. Conclusions: Clear orthodontic aligners release microplastics after periods of exposure. Acidic, carbonated, and alcoholic beverages intensify the degradation of the material, while alkaline media, although also causing degradation, have a more moderate effect. These results reinforce the importance of complying with clinical recommendations to remove aligners when consuming beverages, preventing material degradation and potential biological risks.
Descrição
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Palavras-chave
Alinhadores transparentes Microplásticos Ortodontia Termoplástico