Influência de diferentes bebidas sobre a rugosidade superficial de resina acrílica termoativada reforçada por nanopartículas
Carregando...
Data
2018-07-27
Autores
Siviero, Yasmin Christi [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Uma estratégia para melhorar as propriedades das resinas acrílicas é o uso da nanotecnologia. Esta abordagem tem atraído grande interesse tanto acadêmico como industrial, devido ao notável incremento de propriedades mecânicas. Neste contexto, as nanopartículas possuem o potencial para modificar significativamente as propriedades de uma matriz polimérica. Esse potencial depende fortemente da natureza física de cada tipo de partícula. Partículas inorgânicas, como montmorilonita, sílica coloidal e partículas de óxido metálico afetam fortemente as propriedades mecânicas, físicas e biológicas. A rugosidade de um material é importante para os fenômenos de superfície como atrito, resistência à fadiga e ao desgaste, propriedades óticas, escoamento de fluidos e adesão, provocando um aumento de superfície e retenção mecânica de pigmentos e biofilme dental. Substâncias de trânsito bucal podem alterar de forma significativa a lisura superficial de resinas acrílicas. Com base nessas considerações, o propósito deste estudo foi verificar o efeito de substâncias de trânsito (saliva artificial, cerveja, café, refrigerante de cola e suco de uva) sobre a rugosidade superficial de resina acrílica ativada termicamente (Clássico®) reforçada por nanopartículas. Para tanto, a partir de matriz metálica de dimensões 15mm x 15mm (raio x altura) foram confeccionados 70 discos de silicone laboratorial polimerizada por condensação (Zetalabor, Zhermack, Itália) os quais foram incluídos (n=10) em 10 muflas metálicas utilizando gesso pedra tipo IV (Durone®, Dentsply Ind. Com., Rio de. Janeiro, Brasil), espatulado manualmente de acordo com a relação água/pó recomendada pelo fabricante e vazado no interior de mufla. Na sequência aguardou-se 30 minutos para a presa do gesso, obtendo-se, dessa forma, o molde para a confecção dos corpos-de-prova de resina acrílica com as mesmas dimensões dos discos de silicone por condensação. Os moldes foram preenchidos com resina acrílica termoativada Clássico® (Artigos Odontológicos Clássico, São Paulo, Brasil) de forma a se preencher cinco muflas com resina não-reforçada (Grupo A) e as outras cinco com resina reforçada (Grupo B). Para reforço foram incorporadas nanopartículas de anatase de óxido de titânio (Sigma Aldrich do Brasil) na concentração de 2% em massa. As muflas foram levadas à polimerização obedecendo o ciclo recomendado pelo fabricante. Após a polimerização e resfriamento da mufla os corpos-de-prova foram desincluídos, submetidos ao acabamento e polimento e a rugosidade superficial mensurada. Os espécimes dos grupos A e B foram divididos aleatoriamente em cinco grupos(n=10): G1-Controle (saliva artificial); GII (cerveja) ; GIII (café); GIV(refrigerante de cola) e GV (suco de uva). Os espécimes foram imersos nas suas respectivas soluções cinco vezes ao dia, por cinco minutos, por 30 dias. Após o período de imersão todos os espécimes foram imersos em saliva artificial por 7 dias, quando então a rugosidade superficial foi novamente mensurada. Os resultados, submetidos a tratamento estatístico, mostraram que, quando o grupo não reforçada cerveja foi comparado aos grupos reforçada saliva artificial e reforçada café, diferenças significativas foram encontradas apontando os melhores resultados para os grupos reforçada saliva artificial e reforçada café. Quando o grupo não reforçada café foi comparado aos grupos reforçada saliva artificial e reforçada café, diferenças significativas também foram encontradas apontando os melhores resultados para os grupos reforçada saliva artificial e reforçada café. Observemos que a substância café provocou menores alterações de rugosidade na resina reforçada. O grupo não reforçada refrigerante de cola teve os piores resultados (maior rugosidade superficial) que todos os grupos reforçados, exceto para o grupo reforçado refrigerante de cola. Assim, a substância refrigerante de cola não produziu alterações estatisticamente significativas nos dois tipos de resina acrílica. Por fim, o grupo não reforçado suco de uva mostrou maiores valores de rugosidade artificial que o grupo reforçado café. Concluiu-se que: a) não houve diferença para as bebidas dentro de uma mesma resina acrílica; para uma mesma bebida; b) a condição reforçada foi melhor que a condição não reforçada quando comparada a influência da bebida café.
One strategy to improve the properties of acrylic resins is the use of nanotechnology. This approach has attracted great interest, both academic and industrial, due to the remarkable increase in mechanical properties. In this context, the nanoparticles have the potential to significantly modify the properties of a polymer matrix. This potential strongly depends on the physical nature of each type of particle. Inorganic particles such as montmorillonite, colloidal silica and metal oxide particles strongly affect the mechanical, physical and biological properties. The roughness of a material is important for surface phenomena such as friction, fatigue and wear resistance, optical properties, fluid flow and adhesion, causing a surface increase and mechanical retention of pigments and dental biofilm. Buccal transit substances can significantly alter the surface smoothness of acrylic resins. Based on these considerations, the purpose of this study was to verify the effect of traffic substances (artificial saliva, beer, coffee, cola and grape juice) on the surface roughness of thermally activated acrylic resin (Clássico®) reinforced by nanoparticles. To do so, 70 disks of condensation polymerized silicone (Zetalabor, Zhermack, Italy) were prepared from metal matrix of 15mm x 15mm (radius x height), which were included (n = 10) in 10 metal muffles using gypsum (Durone®, Dentsply Ind. Com., Rio de Janeiro, Brazil), manually spatulated according to the water / powder ratio recommended by the manufacturer and cast into the muffle. A further 30 minutes were then taken for the casting of the gypsum, thereby obtaining the mold for the preparation of the acrylic resin specimens having the same dimensions of the silicone discs by condensation. The molds were filled with Classical® thermoactivated acrylic resin (Classical Dental Articles, São Paulo, Brazil) in order to fill five muflas with non-reinforced resin (Group A) and the other five with reinforced resin (Group B). For reinforcement, nanoparticles of titanium oxide anatase (Sigma Aldrich do Brasil) were incorporated in the concentration of 2% by mass. The muffles were taken to the polymerization following the cycle recommended by the manufacturer. After the polymerization and cooling of the muffle, the specimens were disinfected, subjected to finishing and polishing and the surface roughness measured. Specimens of groups A and B were randomly divided into five groups (n = 10): G1-Control (artificial saliva); GII (beer); GIII (coffee); GIV (cola refrigerant) and GV (grape juice). The specimens were immersed in their respective solutions five times a day, for five minutes, for 30 days. After the immersion period all the specimens were immersed in artificial saliva for 7 days, when the surface roughness was again measured. The results, submitted to statistical treatment, showed that when the group not strengthened beer was compared to the groups enhanced artificial saliva and enhanced coffee, significant differences were found pointing the best results for the groups enhanced artificial saliva and enhanced coffee. When the non-enhanced coffee group was compared to the groups enhanced artificial saliva and enhanced coffee, significant differences were also found pointing the best results for the groups enhanced artificial saliva and enhanced coffee. We observed that the coffee substance caused minor changes of roughness in the reinforced resin. The unreinforced cola group had the worst results (greater surface roughness) than all the reinforced groups, except for the reinforced cola group. Thus, the glue-free substance did not produce statistically significant changes in the two types of acrylic resin. Finally, the unreinforced grape juice group showed higher values of artificial roughness than the reinforced coffee group. It was concluded that: a) there was no difference for the beverages within the same acrylic resin; for a same beverage, the enhanced condition was better than the non-enhanced condition when compared to the influence of the coffee beverage.
One strategy to improve the properties of acrylic resins is the use of nanotechnology. This approach has attracted great interest, both academic and industrial, due to the remarkable increase in mechanical properties. In this context, the nanoparticles have the potential to significantly modify the properties of a polymer matrix. This potential strongly depends on the physical nature of each type of particle. Inorganic particles such as montmorillonite, colloidal silica and metal oxide particles strongly affect the mechanical, physical and biological properties. The roughness of a material is important for surface phenomena such as friction, fatigue and wear resistance, optical properties, fluid flow and adhesion, causing a surface increase and mechanical retention of pigments and dental biofilm. Buccal transit substances can significantly alter the surface smoothness of acrylic resins. Based on these considerations, the purpose of this study was to verify the effect of traffic substances (artificial saliva, beer, coffee, cola and grape juice) on the surface roughness of thermally activated acrylic resin (Clássico®) reinforced by nanoparticles. To do so, 70 disks of condensation polymerized silicone (Zetalabor, Zhermack, Italy) were prepared from metal matrix of 15mm x 15mm (radius x height), which were included (n = 10) in 10 metal muffles using gypsum (Durone®, Dentsply Ind. Com., Rio de Janeiro, Brazil), manually spatulated according to the water / powder ratio recommended by the manufacturer and cast into the muffle. A further 30 minutes were then taken for the casting of the gypsum, thereby obtaining the mold for the preparation of the acrylic resin specimens having the same dimensions of the silicone discs by condensation. The molds were filled with Classical® thermoactivated acrylic resin (Classical Dental Articles, São Paulo, Brazil) in order to fill five muflas with non-reinforced resin (Group A) and the other five with reinforced resin (Group B). For reinforcement, nanoparticles of titanium oxide anatase (Sigma Aldrich do Brasil) were incorporated in the concentration of 2% by mass. The muffles were taken to the polymerization following the cycle recommended by the manufacturer. After the polymerization and cooling of the muffle, the specimens were disinfected, subjected to finishing and polishing and the surface roughness measured. Specimens of groups A and B were randomly divided into five groups (n = 10): G1-Control (artificial saliva); GII (beer); GIII (coffee); GIV (cola refrigerant) and GV (grape juice). The specimens were immersed in their respective solutions five times a day, for five minutes, for 30 days. After the immersion period all the specimens were immersed in artificial saliva for 7 days, when the surface roughness was again measured. The results, submitted to statistical treatment, showed that when the group not strengthened beer was compared to the groups enhanced artificial saliva and enhanced coffee, significant differences were found pointing the best results for the groups enhanced artificial saliva and enhanced coffee. When the non-enhanced coffee group was compared to the groups enhanced artificial saliva and enhanced coffee, significant differences were also found pointing the best results for the groups enhanced artificial saliva and enhanced coffee. We observed that the coffee substance caused minor changes of roughness in the reinforced resin. The unreinforced cola group had the worst results (greater surface roughness) than all the reinforced groups, except for the reinforced cola group. Thus, the glue-free substance did not produce statistically significant changes in the two types of acrylic resin. Finally, the unreinforced grape juice group showed higher values of artificial roughness than the reinforced coffee group. It was concluded that: a) there was no difference for the beverages within the same acrylic resin; for a same beverage, the enhanced condition was better than the non-enhanced condition when compared to the influence of the coffee beverage.
Descrição
Palavras-chave
Resinas acrílicas, Propriedades de superfície, Polimerização, Nanopartículas