Loading...
Publication
Estudo in vitro da resistência adesiva à dentina utilizando um adesivo universal com a estratégia selective dentin etching após envelhecimento químico
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 3.9 MB | Adobe PDF |
Abstract(s)
Objetivos: Avaliar in vitro a resistência adesiva à dentina, através de um ensaio de microtração (μTBS), utilizando o adesivo Optibond™ Universal® com a estratégia adesiva selective dentin etching após envelhecimento químico; classificar as falhas obtidas; e avaliar a interface adesiva através de microscopia eletrónica de varrimento (MEV).
Materiais e métodos: Trinta molares humanos definitivos hígidos foram preparados e distribuídos aleatoriamente por três grupos experimentais (n = 10): Grupo SE (controlo) – aplicação do adesivo Optibond™ Universal® com a técnica self-etch; Grupo SDE1 – aplicação do adesivo Optibond™ Universal® com a técnica selective dentin etching; Grupo SDE3 – aplicação de três camadas do adesivo Optibond™ Universal® com a técnica selective dentin etching. Após a exposição da dentina superficial e simulação da smear layer, foram aplicados o sistema adesivo e a resina composta. Depois procedeu-se ao envelhecimento químico dos dentes com flutuações de pH em ciclos de 6 horas em saliva artificial de pH=3 e 18 horas em pH=6,4, durante 28 dias. De seguida, os dentes foram seccionados em palitos de 1 mm2 e submetidos ao μTBS numa máquina universal (1 kN; 0.5 mm/min) até ocorrer a fratura. As zonas de fratura foram observadas num estereomicroscópio e a falha foi classificada. Antes do teste de microtração, foi selecionado aleatoriamente um palito de cada grupo para observação ao MEV. Os resultados obtidos foram analisados estatisticamente através de teste ANOVA one-way com Tukey (nível de significância 5%, SPSS v. 28.0.0.0).
Resultados: Não se observaram diferenças estatisticamente significativas (p > 0,05) nos valores de resistência adesivas dos três grupos experimentais. A maioria das falhas foram adesivas e as imagens obtidas no MEV revelaram uma melhor difusão do adesivo nos grupos SDE1 e SDE3.
Conclusões: A resistência adesiva à dentina com a utilização do adesivo Optibond™ Universal® não foi influenciada pela estratégia adesiva selective dentin etching após envelhecimento químico.
Objectives: To evaluate in vitro the microtensile bond strength (μTBS) to dentin, using the Optibond™ Universal® adhesive with the selective dentin etching adhesive technique after chemical ageing; classify the obtained failures; and describe the adhesive interface through scanning electron microscopy (SEM). Materials and methods: Thirty healthy permanent human molars were prepared and randomly assigned to three experimental groups (n = 10): Group SE (control) – application of Optibond™ Universal® adhesive using the self-etch technique; Group SDE1 (experimental) – application of Optibond™ Universal® adhesive using the selective dentin etching technique; Group SDE3 (experimental) – application of three layers of Optibond™ Universal® adhesive. After exposing the superficial dentin and simulating the smear layer, the adhesive system and composite resin were applied. The samples were then chemically aged using pH fluctuations in cycles of 6 hours in pH=3 saliva artificial and 18 hours in pH=6.4 for 28 days. After aging, the teeth were sectioned into 1 mm2 sticks and the μTBS was performed in a universal machine (1 kN; 0.5 mm/min) until fracture occurred. The fracture zones were observed under a stereomicroscope and the failure was classified. Before the microtensile test, a stick was randomly selected from each group to be observed under a scanning electron microscope (SEM) and the adhesive interface was analysed. The results were statistically analysed using a one-way ANOVA test with Tukey (5% significance level, SPSS v. 28.0.0.0). Results: There were no statistically significant differences (p > 0.05) in the microtensile bond strength values of the three experimental groups. Most of the failures were adhesive and the SEM images showed better adhesive diffusion in the SDE1 and SDE3 groups. Conclusions: Bond strength to dentin using Optibond™ Universal® adhesive was not influenced by the selective dentin etching strategy after chemical aging.
Objectives: To evaluate in vitro the microtensile bond strength (μTBS) to dentin, using the Optibond™ Universal® adhesive with the selective dentin etching adhesive technique after chemical ageing; classify the obtained failures; and describe the adhesive interface through scanning electron microscopy (SEM). Materials and methods: Thirty healthy permanent human molars were prepared and randomly assigned to three experimental groups (n = 10): Group SE (control) – application of Optibond™ Universal® adhesive using the self-etch technique; Group SDE1 (experimental) – application of Optibond™ Universal® adhesive using the selective dentin etching technique; Group SDE3 (experimental) – application of three layers of Optibond™ Universal® adhesive. After exposing the superficial dentin and simulating the smear layer, the adhesive system and composite resin were applied. The samples were then chemically aged using pH fluctuations in cycles of 6 hours in pH=3 saliva artificial and 18 hours in pH=6.4 for 28 days. After aging, the teeth were sectioned into 1 mm2 sticks and the μTBS was performed in a universal machine (1 kN; 0.5 mm/min) until fracture occurred. The fracture zones were observed under a stereomicroscope and the failure was classified. Before the microtensile test, a stick was randomly selected from each group to be observed under a scanning electron microscope (SEM) and the adhesive interface was analysed. The results were statistically analysed using a one-way ANOVA test with Tukey (5% significance level, SPSS v. 28.0.0.0). Results: There were no statistically significant differences (p > 0.05) in the microtensile bond strength values of the three experimental groups. Most of the failures were adhesive and the SEM images showed better adhesive diffusion in the SDE1 and SDE3 groups. Conclusions: Bond strength to dentin using Optibond™ Universal® adhesive was not influenced by the selective dentin etching strategy after chemical aging.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Resistência adesiva Adesivo universal Dentina Envelhecimento químico