• Title/Summary/Keyword: nano-material

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Shear bond strength of dental CAD-CAM hybrid restorative materials repaired with composite resin (치과용 복합레진으로 수리된 CAD-CAM hybrid 수복물의 전단결합강도)

  • Moon, Yun-Hee;Lee, Jonghyuk;Lee, Myung-Gu
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.3
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    • pp.193-202
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    • 2016
  • Purpose: This study was performed in order to assess the effect of the surface treatment methods and the use of bonding agent on the shear bond strength (SBS) between the aged CAD-CAM (computer aided design-computer aided manufacturing) hybrid materials and added composite resin. Materials and methods: LAVA Ultimate (LU) and VITA ENAMIC (VE) specimens were age treated by submerging in a $37^{\circ}C$ water bath filled with artificial saliva (Xerova solution) for 30 days. The surface was ground with #220 SiC paper then the specimens were divided into 9 groups according to the combination of the surface treatment (no treatment, grinding, air abrasion with aluminum oxide, HF acid) and bonding agents (no bonding, Adper Single Bond 2, Single Bond Universal). Each group had 10 specimens. Specimens were repaired (added) using composite resin (Filtek Z250), then all the specimens were stored for 7 days in room temperature distilled water. SBS was measured and the fractured surfaces were observed with a scanning electron microscope (SEM). One-way ANOVA and Scheffe test were used for statistical analysis (${\alpha}=.05$). Results: Mostly groups with bonding agent treatment showed higher SBS than groups without bonding agent. Among the groups without bonding agent the groups with aluminum oxide treatment showed higher SBS. However there was no significant difference between groups except two subgroups within LU group, which revealed a significant increase of SBS when Single Bond Universal was used on the ground LU specimen. Conclusion: The use of bonding agent when repairing an aged LAVA Ultimate restoration is recommended.

Physiological Activities of Fermented Gastrodia elata Blume Extracts (발효 천마 추출물의 생리 활성)

  • Park, An Na;Ku, Tae Kyu;Kim, Kyung Sun;Lee, Dong Won;Kim, Sang Jin
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.702-711
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    • 2015
  • This study was conducted to determine the feasibility of using Gastrodia elata Blume as a cosmetic raw material by investigating the physiological activities of its extracts, varying the concentration, solvent, and fermentation method (non-fermentation and fermentation using lactic acid bacteria and effective microorganisms). Of the extracts in three different solvents-water, EtOH, and 70% EtOH-at four different concentrations (0.725, 1.25, 2.5, and 5 mg/mL), the EtOH extracts demonstrated the highest contents of antioxidants (flavonoids, polyphenols, and DPPH free radical scavengers). The DPPH free radical scavenging activity in the EtOH extracts of EM-fermented Gastrodia elata Blume increased from $27.08{\pm}0.5%$ at 1.25 mg/mL to $35.89{\pm}0.8%$ at 2.5 mg/mL. The tyrosinase inhibitory activity test was performed to measure skin-whitening capacity and revealed the LB-fermented EtOH extracts to be the most efficacious ($39.1{\pm}0.4%$ at 0.725 mg/mL, $62.8{\pm}1.5%$ at 2.5 mg/mL). Viability was found to exceed 85% in RAW 264.7 cells treated with all extracts (water, EtOH, 70% EtOH at 10, 25, $50{\mu}L$, fermented and non-fermented), thus proving that Gastrodia elata Blume extracts do not cause inflammation. When RAW 264.7 cells were stimulated with lipopolysaccharide as positive controls under the same conditions to determine the antioxidant activity in the presence of reactive oxygen species (ROS), EM-fermentation was found to impart excellent antioxidant capacity. This study verified the physiological activities of fermented Gastrodia elata Blume extracts that are best suited for cosmetic ingredients, such as antioxidants, tyrosinase inhibitors and anti-inflammatory agents.

Functional Properties of Walnut in Cosmetics (호두의 화장품 기능성)

  • Kim, Mee-Kyung;Kim, Jin-Sung;Jo, Bun-Sung;Kim, Jeung-Hoan;Lee, In-Cheol;Lee, Myung-Sup;Cho, Young-Je
    • Journal of Life Science
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    • v.21 no.6
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    • pp.858-864
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    • 2011
  • The phenolic compounds of walnut extracts by various solvents were shown to be 24.3 mg/g in hot water, 34.4 mg/g in ethanol, 32.5 mg/g in methanol and 15.1 mg/g in acetone. In a comparison of phenolic compounds from hot water and different concentrations of ethanol, which are harmless, 60% ethanol extract and hot water extract were 34.7 mg/g, 24.6 mg/g. The electron donating ability (EDA) of walnut extracts in hot water and 60% ethanol were 78.1% and 80.6%. According to ABTS radical cation decolorization for antioxidant activity, hot water and 60% ethanol extract showed high antioxidant activities of 98.1% and 98.3%. Antioxidant protection factor (PF) were $1.1{\pm}0.2$ PF and $1.1{\pm}0.4$ PF in hot water and 60% ethanol extract. In TBARs inhibitory activity, each extract showed high antioxidant activities at 60% and 75%. Anti-inflammation effects of walnut extract were tested, and inhibition of NO was 50% in 100 ${\mu}g/ml$ phenolics. Inhibitory activity against iNOS and COX-2 were shown, through Western blot, to be 10% in 100 ${\mu}g/ml$ phenolics. Tyrosine inhibitory activity of 60% ethanol extract was 43%, and astringent effect of 60% ethanol extract was 55%. These results suggest that walnut extracts are suitable for functional cosmetics requiring skin-whitening and anti-wrinkle activity.