Department of Conservative Dentistry, School of Dentistry, Kyung Hee National University, Seoul, Republic of Korea.
Dent Mater. 2010 Aug;26(8):771-8. doi: 10.1016/j.dental.2010.04.001. Epub 2010 May 15.
The purposes of this work were to quantitate the affinity and binding capacity of chlorhexidine (CHX) digluconate to mineralized versus demineralized dentin powder and to determine how much debinding would result from rinsing with water, ethanol, hydroxyethylmethacrylate (HEMA) or 0.5M NaCl in water.
Dentin powder was made from coronal dentin of extracted human third molars. Standard amounts of dentin powder were tumbled with increasing concentrations of CHX (0-30 mM) for 30 min at 37 degrees C. After centrifuging the tubes, the supernatant was removed and the decrease in CHX concentration quantitated by UV-spectroscopy. CHX-treated dentin powder was resuspended in one of the four debinding solutions for 3 min. The amount of debound CHX in the solvents was also quantitated by UV-spectroscopy.
As the CHX concentration in the medium increased, the CHX binding to mineralized dentin powder also increased up to 6.8 micromol/g of dry dentin powder. Demineralized dentin powder took up significantly (p<0.01) more CHX, reaching 30.1 micromol CHX/g of dry dentin powder. Debinding of CHX was in the order: HEMA<ethanol<0.05 M NaCl<water. The highest CHX binding to demineralized dentin occurred at 30 mM (1.5 wt.%).
As CHX is not debound by HEMA, it may remain bound to demineralized dentin during resin-dentin bonding. This may be responsible for the long-term efficacy of CHX as an MMP inhibitor in resin-dentin bonds.
本研究旨在定量分析洗必泰二葡萄糖酸盐（CHX）与矿化和脱矿牙本质粉的亲和力和结合容量，并确定用水、乙醇、羟乙基甲基丙烯酸酯（HEMA）或 0.5M NaCl 冲洗会导致多少 CHX 洗脱。
牙本质粉取自离体第三磨牙的冠部牙本质。将标准量的牙本质粉与浓度逐渐增加的 CHX（0-30mM）在 37°C 下旋转 30 分钟。离心管后，去除上清液，通过紫外分光光度法定量测定 CHX 浓度的降低。将 CHX 处理过的牙本质粉重新悬浮在四种脱附溶液中的一种中 3 分钟。通过紫外分光光度法也定量测定了溶剂中洗脱的 CHX 量。
随着介质中 CHX 浓度的增加，矿化牙本质粉对 CHX 的结合也增加，达到 6.8µmol/g 牙本质粉干重。脱矿牙本质粉吸收了更多的 CHX，达到 30.1µmol CHX/g 牙本质粉干重。CHX 的洗脱顺序为：HEMA<乙醇<0.05M NaCl<水。脱矿牙本质对 CHX 的最大结合发生在 30mM（1.5wt.%）。
由于 HEMA 不会使 CHX 脱附，因此它可能在树脂-牙本质粘结过程中保持与脱矿牙本质结合。这可能是 CHX 作为 MMP 抑制剂在树脂-牙本质粘结中具有长期疗效的原因。
