Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok, 10400, Thailand.
Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok, 10400, Thailand.
Arch Oral Biol. 2020 Nov;119:104885. doi: 10.1016/j.archoralbio.2020.104885. Epub 2020 Aug 27.
To determine the rate of fluid flow through human dentine due to electroosmosis during iontophoresis of either 2 % lignocaine with epinephrine, Ringer's solution, epinephrine, or distilled water.
Experiments were carried out on 24 intact extracted human premolars. Dentine was exposed at the tip of the buccal cusp. The cavity was filled with one of the test solutions and the pulp cavity, with Ringer's solution at a pressure of 11 mm Hg. Fluid flow through the dentine was measured using a capillary connected to the pulp cavity. Current was passed between a stainless-steel electrode in the cavity and one in the pulp cavity. The results were analysed using repeated measures, three-way ANOVA, with Bonferroni pairwise comparisons where this showed a significant effect.
The current passed produced a significant flow of fluid through the dentine but neither the composition of the test solution nor etching had a significant effect on the flow. During iontophoresis of 2 % lignocaine with epinephrine for example, currents of 0.2, 0.4, and 0.6 mA applied with the cavity electrode as anode produced inward flow rates of 2.25 ± 0.87, 5.00 ± 1.62, 8.60 ± 1.97 (mean ± s.d.) nL/s/mm² respectively, and applying the currents in the opposite direction caused outward flows of 0.76 ± 0.72, 1.00 ± 1.01, 1.12 ± 1.18 nL/s/mm² respectively.
It is concluded that electroosmosis can be produced in human dentine, it can enhance the effect of iontophoresis in transporting charged molecules through dentine, particularly large molecules, and it could also enable uncharged molecules to be carried through dentine into the pulp.
确定在电渗离子导入 2% 利多卡因加肾上腺素、林格氏液、肾上腺素或蒸馏水时，电渗通过人牙本质的流体流速。
在 24 颗完整的人前磨牙上进行实验。在颊尖处暴露牙本质。将腔填充有一种测试溶液，牙髓腔填充林格氏液，压力为 11 毫米汞柱。通过与牙髓腔相连的毛细管测量牙本质内的流体流动。在腔内的不锈钢电极和牙髓腔内的一个电极之间传递电流。使用重复测量、三向方差分析对结果进行分析，并在有显著影响时进行 Bonferroni 配对比较。
传递的电流会导致牙本质内的流体显著流动，但测试溶液的组成或蚀刻均未对流动产生显著影响。例如，在电渗离子导入 2% 利多卡因加肾上腺素时，腔内电极作为阳极施加 0.2、0.4 和 0.6 mA 的电流，分别产生 2.25±0.87、5.00±1.62 和 8.60±1.97 nL/s/mm² 的内向流速，而施加相反方向的电流则分别产生 0.76±0.72、1.00±1.01 和 1.12±1.18 nL/s/mm² 的外向流速。
可以得出结论，电渗可以在人牙本质中产生，它可以增强离子导入通过牙本质输送带电分子的效果，特别是大分子，并且还可以使不带电的分子通过牙本质进入牙髓。
