Estabilidade mecânica e atividade proteolítica de interfaces produzidas com a técnica de adesão seca à dentina biomodificada
Data
2019-03-01
Autores
Citta, Mariana
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Objetivo: Avaliar a estabilidade mecânica e a atividade proteolítica de interfaces produzidas pela apliação de um adesivo convencional simplificado sobre a dentina biomodificada e seca. Métodos: Superfícies planas de dentina coronária foram criadas em 64 molares hígidos. Os dentes foram divididos em 4 grupos de acordo com a solução aplicada sobre a dentina condicionada: extrato de semente de uva 5% (GSE), glutaraldeído 5% (GD), Gluma Desensitizer ou água (controle). As soluções foram aplicadas por 60s seguido de lavagem e secagem com papel absorvente. Os dentes foram então subdivididos em dois grupos, nos quais a dentina condicionada foi mantida úmida ou foi seca com ar por 60s. O adesivo Optibond foi aplicado e em seguida foi construído um cilindro de resina. Decorridas 24h, os dentes foram cortados em espécimes (0,81 mm2 ), submetidos ao ensaio de microtração imediatamente ou após 12 meses de envelhecimento. Os mesmos procedimentos adesivos foram realizados em 32 dentes adicionais. Esses dentes foram seccionados em fatias de 0,5 mm de espessura, preparadas para os ensaios de nanoinfiltração e zimografia in situ (EnzChek). Os dados de resistência de união foram submetidos aos testes de ANOVA e Tukey (p<0,05), e os ensaios de nanoinfiltração e zimografia in situ foram apresentados descritivamente. Resultados: Redução significante da resistência de união imediata (ca. 65%) e aumento da atividade proteolítica e nanoilfiltração foi observado em interfaces produzidas sobre a dentina seca, sem previa biomodificação. Diferentemente, os valores de resistência de união não diferiram dos obtidos para a dentina úmida quando o colágeno foi biomodificado antes da secagem com ar. Interfaces produzidas sobre a dentina úmida e seca foram estáveis após 12 meses apenas quando a dentina foi biomodificada por GSE, GD ou Gluma. Conclusão: Interfaces produzidas pela aplicação de um adesivo convencional simplificado sobre a dentina biomodificada e seca foram mecanicamente estáveis e apresentaram reduzida atividade proteolítica após um ano de envelhecimento.
Objective: To evaluate the mechanical stability and the proteolytic activity of bonds created by a one-step, etch-and-rinse adhesive applied to cross-linked and air-dried etched dentin. Methods: Flat coronal dentin surfaces were produced in 64 sound molars. The teeth were divided into 4 groups according to the solution applied on the etched dentin: 5% grape seed extract, 5% glutaraldehyde, Gluma Desensitizer or deionized water (control). Solutions were applied for 60s followed by rinse and blot drying. Then, the teeth were separated into two subgroups: the etched dentin was kept moist or air dried for 60s. Optibond was applied followed by a composite resin buildup. After 24h, the teeth were cut into beams (0.81 mm²) which were microtensile tested immediately or after 12mo of storage. Additional teeth (n=32) were bonded as described and cut into 0.5 mm-thick slabs. The slabs were prepared for nanoleakage and in situ zymography analyses (EnzChek). Bond strength data were submitted to ANOVA and Tukey tests (p<0.05) while nanoleakage and zymography data were descriptively reported. Results: Significant reduction in bond strength (ca. 65%) and increase of the proteolytic activity was seen when the etched dentin was air-dried without previous biomodification. Conversely, bond strengths did not differ from those produced on wet dentin when collagen was cross-linked before air-drying, irrespective of the solution. For both moist and air-dried etched dentin, collagen cross-linking resulted in mechanically stable bonds and reduced proteolytic activity. Conclusion: Bonds produced by the application of a one-step, etch-and-rinse adhesive to cross-linked, air-dried etched dentin became mechanically stable and revealed reduced proteolytic activity after one year of aging.
Objective: To evaluate the mechanical stability and the proteolytic activity of bonds created by a one-step, etch-and-rinse adhesive applied to cross-linked and air-dried etched dentin. Methods: Flat coronal dentin surfaces were produced in 64 sound molars. The teeth were divided into 4 groups according to the solution applied on the etched dentin: 5% grape seed extract, 5% glutaraldehyde, Gluma Desensitizer or deionized water (control). Solutions were applied for 60s followed by rinse and blot drying. Then, the teeth were separated into two subgroups: the etched dentin was kept moist or air dried for 60s. Optibond was applied followed by a composite resin buildup. After 24h, the teeth were cut into beams (0.81 mm²) which were microtensile tested immediately or after 12mo of storage. Additional teeth (n=32) were bonded as described and cut into 0.5 mm-thick slabs. The slabs were prepared for nanoleakage and in situ zymography analyses (EnzChek). Bond strength data were submitted to ANOVA and Tukey tests (p<0.05) while nanoleakage and zymography data were descriptively reported. Results: Significant reduction in bond strength (ca. 65%) and increase of the proteolytic activity was seen when the etched dentin was air-dried without previous biomodification. Conversely, bond strengths did not differ from those produced on wet dentin when collagen was cross-linked before air-drying, irrespective of the solution. For both moist and air-dried etched dentin, collagen cross-linking resulted in mechanically stable bonds and reduced proteolytic activity. Conclusion: Bonds produced by the application of a one-step, etch-and-rinse adhesive to cross-linked, air-dried etched dentin became mechanically stable and revealed reduced proteolytic activity after one year of aging.
Descrição
Palavras-chave
Adesivos dentinários, Envelhecimento, Dentina, Inibidores de proteases, Reagentes para ligação cruzada, Resistência à tração, Dentin bonding agents, Aging, Dentin, Proteases inhibitors, Cross-linking agents, Bond strength