School of Dentistry and Graduate Institute of Clinical Dentistry, National Taiwan University and National Taiwan University Hospital, No. 1, Chang-Te Street, Taipei 10016, Taiwan.
Department of Chemistry, National Cheng Kung University, No. 1, Daxue Rd., Tainan City, 701, Taiwan.
J Dent. 2019 Apr;83:61-66. doi: 10.1016/j.jdent.2019.02.007. Epub 2019 Feb 27.
The aim of this study was to investigate the novel mesocellular siliceous foams (MCF) containing CaCO nanoparticles (denoted as CMCF) combined with phosphoric acid could occlude dentinal tubules through the formation of biomimetic crystal barrier.
Ultrastructures of MCF and CMCF were examined by transmission electron microscopy (TEM). Elemental components were analyzed with energy dispersive X-ray spectrometry (EDX). CMCF was mixed with distilled water, 10%, 20% and 30% phosphoric acid then applied on dentine discs. Crystals were characterized by X-ray powder diffractometry (XRD). The sealing efficacy of the dentinal tubules was examined by scanning electron microscopy.
TEM images showed MCF presented a pore size of approximately 30.0 nm and CMCF contained abundant nano-CaCO. Sealing efficacy showed that CMCF, when reacted with 30% phosphoric acid, would form crystals in the dentinal tubules to a depth of 83.2 ± 17.6 μm at an occlusion percentage of 75.6 ± 12.8% on average; both occlusion percentage and depth were higher than those obtained with 10% or 20% phosphoric acid (p < 0.05). The results of XRD and EDS indicated that the crystal growth in the dentinal tubules could be transformed into the biomimetic crystals.
This study showed that the CMCF with 30% phosphoric acid could effectively occlude the dentinal tubules through the formation of biomimetic crystal barrier.
The novel CMCF combined with phosphoric acid may have potential for the treatment of dentine hypersensitivity.
本研究旨在探讨含有碳酸钙纳米颗粒的新型介孔硅泡沫（CMCF）与磷酸结合后能否通过形成仿生晶体屏障来封闭牙本质小管。
通过透射电子显微镜（TEM）观察 MCF 和 CMCF 的超微结构。用能谱仪（EDX）分析元素成分。将 CMCF 与蒸馏水、10%、20%和 30%磷酸混合，然后涂于牙本质片上。用 X 射线粉末衍射仪（XRD）对晶体进行表征。扫描电子显微镜观察牙本质小管的封闭效果。
TEM 图像显示 MCF 的孔径约为 30.0nm，CMCF 含有丰富的纳米 CaCO。封闭效果显示，当 CMCF 与 30%磷酸反应时，会在牙本质小管中形成晶体，深度为 83.2±17.6μm，平均闭塞率为 75.6±12.8%；与 10%或 20%磷酸相比，闭塞率和深度均较高（p<0.05）。XRD 和 EDS 的结果表明，牙本质小管内的晶体生长可以转化为仿生晶体。
本研究表明，含 30%磷酸的 CMCF 可通过形成仿生晶体屏障有效封闭牙本质小管。
新型 CMCF 与磷酸结合可能为治疗牙本质敏感症提供新的方法。
