| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥600,000)
Fiscal Year 2007: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
The purpose of this study was to produce an antibacterial adhesive for orthodontic bonding without compromising the mechanical property. We added green tea catechin to the Superbond C&B (4-META/MMA-TBB)resin that exhibits a strong bonding strength between enamel and bracket. The catechins used in this study were(+)-catechin, (-)-epicatechin (EC), (-)-epigallocatechin(EGC), (-)-epicatechin gallate(ECg), and (-)-epigallocatechin gallate(EGCg). Each catechin concentrations in the catechin-composites were 10.0%(wt/wt). The sample disks of uniform size(8.0mm diameter ×2.0mm thick)were made from all the catechin-composites using custom-made molds. Oral cariogenic streptococci, Streptococcus mutans NCTC10449 was used as the test bacteria. The disks were put in the bacteria infusion at 37℃ for 24h. They were divided into a disk and bacteria infusion. Each bacteria were prepared in TH buffer. The mitis salivarius agar were cultured anaerobically at 37℃ for 48h, and the number of colony forming unite(CFU) were counted.
As a result of bacteria stuck to the disk, The CFU decreased with (+)-catechin, EGC, ECg, EGCg composite. As a result of bacteria infusion that catechin released, The catechin-composite samols showed significant antibacterial activity compared with the control.
The catechin-composites were used to bond metal brackets to self-etching primed enamel surface of human premolars. The shear bond strengths were measured after immersion in water at 37℃ for 24h.
As a result of shear bond strengths, A sign cant difference was found between the control composite and EGCg and ECg composite. However, the bond strength was more strong than 10MPa
These results confirmed that clinically acceptable bond strength was preserved in 4-META/MMA-TBB resin with added green tea catechin.
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