IADR Abstract Archives
Influence of Novel Bioactive Materials on Dentinal Enzymatic Activity
Objectives: To evaluate the influence of Activa Base/Liner and Activa Restorative on the activity of dentinal endogenous proteases at baseline and after aging using in situ zymography.
Methods: Extracted human third molars were sectioned into 1-mm-thick sections of middle/deep coronal dentin. A standardized smear layer was created with 600-grit wet silicon-carbide paper. Dentin samples were randomly divided and restored either with Activa Base/Liner or Activa Restorative. In situ zymographic assay was performed on sections of dentin after 24h (T0), or after 1-month-aging (T1) at 37°C in artificial saliva, in accordance with Mazzoni et al., 2014. Bonded slabs of dentin were glued to a slide and polished until approximately 50μm-thick. Fifty microliters of a stock solution containing self-quenched fluorescein-conjugated gelatin were placed on top of each specimen and incubated in a humidified chamber at 37 °C for 12 h. Detection of endogenous gelatinolytic enzyme activity was based on hydrolysis of the quenched fluorescein-conjugated gelatin presented as green fluorescence under confocal laser-scanning microscope. The stacked images were qualitative analyzed.
Results: T0 revealed a middle to low level of fluorescence present within the interdiffusion layer, as well as in the dentin for Activa Base/Liner. For Activa Restorative a green fluorescence of middle intensity within the interdiffusion layer could be noticed, while a low intensity of fluorescence was detected in dentin. At T1 an intense green fluorescence within the both bioactive materials could be seen, while the activity in the dentinal substrate was not very expressed. Some fluorescence could be noticed within the bioactive materials for both times.
Conclusions: Activa Base/Liner and Activa Restorative presented a low activity of dentainal endogenous proteases in the substrate at base line, as well as after aging, when compared to other self-etch adhesives. Further studies are necessary to completely understand the behavior of this material
Methods: Extracted human third molars were sectioned into 1-mm-thick sections of middle/deep coronal dentin. A standardized smear layer was created with 600-grit wet silicon-carbide paper. Dentin samples were randomly divided and restored either with Activa Base/Liner or Activa Restorative. In situ zymographic assay was performed on sections of dentin after 24h (T0), or after 1-month-aging (T1) at 37°C in artificial saliva, in accordance with Mazzoni et al., 2014. Bonded slabs of dentin were glued to a slide and polished until approximately 50μm-thick. Fifty microliters of a stock solution containing self-quenched fluorescein-conjugated gelatin were placed on top of each specimen and incubated in a humidified chamber at 37 °C for 12 h. Detection of endogenous gelatinolytic enzyme activity was based on hydrolysis of the quenched fluorescein-conjugated gelatin presented as green fluorescence under confocal laser-scanning microscope. The stacked images were qualitative analyzed.
Results: T0 revealed a middle to low level of fluorescence present within the interdiffusion layer, as well as in the dentin for Activa Base/Liner. For Activa Restorative a green fluorescence of middle intensity within the interdiffusion layer could be noticed, while a low intensity of fluorescence was detected in dentin. At T1 an intense green fluorescence within the both bioactive materials could be seen, while the activity in the dentinal substrate was not very expressed. Some fluorescence could be noticed within the bioactive materials for both times.
Conclusions: Activa Base/Liner and Activa Restorative presented a low activity of dentainal endogenous proteases in the substrate at base line, as well as after aging, when compared to other self-etch adhesives. Further studies are necessary to completely understand the behavior of this material