• The Journal of the Korea Contents Association
• /
• v.18 no.3
• /
• pp.542-549
• /
• 2018

In this study BGn-incorporated non-fluoride release of pit and fissure sealant $Concise^{TM}$ was developed to improve the mechanical properties and promote antibacterial effect of fit and fissure sealant with the original material. The mechanical properties and antibacterial activity of BGn incorporating vary-ing amounts bioactive glass nano particles(BGn) (0,0.5,1.0 and 2.0 wt% in sealant) were characterized composition of the resulting were investigated. The solubility to aid absorption was calculated by weighing specimens with a diameter of 10 mm and a thickness of 2 mm according to ISO 4049 (2009). The antimicrobial effect was evaluated using three strains of S. mutans, S. aureus and E. coli. The absorbance of the test results was as high as the addition of BGn increased, and the lower the solubility as the solubility was added(p<0.05). Adhesion experiment results S. mutans in contrast to the control group $Concise^{TM}$, BGn-added experimental group showed a somewhat lower adherent surface but no statistically significant difference was observed (p<0.05). However S. aureus and E. coli statistical analysis indicated a significant difference for antibacterial agents between control and BGn containing(p<0.05). It seems that this BGn proved that even a antibacterial effect was demonstrated. Therefore, it was suggest that the additional effects of BGn and research on a wide range of substances.

• Applied Chemistry for Engineering
• /
• v.10 no.4
• /
• pp.599-602
• /
• 1999

Chitosan was depolymerized by using nitrous acid. In order to synthesize new fluorinated chitosan oligomer(FCO) derivative, free amine groups of resulting low molucular weight chitosan oligomers were reacted with trifluoroacetic anhydride. The structure changes in the samples were conformed by using FT-IR, $^{1}H\;NMR$, $^{13}C\;NMR$ and $^{19}F\{^{1}H\}NMR$. Antiviral activity of FCO was studied by measuring DAN amounts of the replication viruses at 36 hr after the cells were infected with the viral solution containing FCO of various concentrations. The viral replications in the cells infected with the viral solution containing FCO were proportionally decreased with the FCO does, compared to those of the control groups, indicating that FCO efficiently inhibits viral infection. In particular, viral replication was decreased to 40% in the 1% FCO-treated cells.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.190-201
• /
• 2004

The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution. The brands studied were Charmfil, Charmfil flow(composite resin), Compoglass F and PrimaFlow(compomer). The results were as follows: 1. The mass loss were not significantly different among the materials(p>0.05). 2. The sequence of the degree of degradation layer depth was in descending order by Compoglass F, PrimaFlow, Charmfil, and Charmfil flow. There were significant differences between Compoglass F and the others(p<0.05). 3. The sequence of the Si loss was in descending order by Charmfil flow, Charmfil, PrimaFlow, and Compoglass F. There were significant differences among these materials(p<0.05). 4. When observed with SEM, destruction of bonding between matrix and filler was observed and when observed with CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Comfoglass, PrimaFlow Charmal, and Charmfil flow. There were significant differences among these materials(p<0.05). 6. The correlation coefficient between Si loss and degradation layer depth (r=0.602, p<0.05) Vicker's hardness number and maximum wear depth (r=0.501, p<0.05) were relatively high. These results indicate that wear and hydrolytic degradation may be considered to be evaluation factors of composite resins and compomers.

• Journal of Food Hygiene and Safety
• /
• v.36 no.3
• /
• pp.264-270
• /
• 2021

In this study we investigated the elution level of lead (Pb), cadmium (Cd), arsenic (As), zinc (Zn), nickel (Ni), antimony (Sb), germanium (Ge), aluminum (Al) and hexavalent chromium (Cr⁶⁺) from 69 home-cooking utensils into a food stimulants. The results of migration testing according to the Korea standards and specifications for utensils, containers and packages showed values the allowable migrantion limits. Al was detected in all 7 utensil materials with the average concentration ranging from 0.002-5.989 mg/L. According to the migration conditions for (180℃, 30 min), the average concentration of Al in paper was 7.2 times higher than 25℃, 10 min (P<0.05). The results of migration testing at 180℃, 30 min were also below the allowable migrantion limits. When comparing with the provisional tolerable weekly intake (PTWI) of Al, the estimated weekly intakes (EWI) accounted for 0.000-0.045% for Al.