Suge Toshiyuki, Kawasaki Akiko, Ishikawa Kunio, Matsuo Takashi, Ebisu Shigeyuki
Department of Conservative Dentistry, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8504, Japan.
Dent Mater. 2008 Feb;24(2):192-8. doi: 10.1016/j.dental.2007.03.009. Epub 2007 Jun 1.
Diamine silver fluoride [AgF: (NH(3))(2)AgF] has been used clinically in Japan, as it reduces dental caries and dentin hypersensitivity. However, AgF stains the teeth black due to silver precipitation. To overcome this drawback, the authors prepared ammonium hexafluorosilicate [SiF: (NH(4))(2)SiF(6)], which does not stain the teeth, and SiF occluded open dentin tubules completely with silica-calcium phosphate precipitate.
The aim of this study was to evaluate the duration of dentin tubule occlusion after SiF treatment in a simulated oral environment.
To simulate dentin tubules subject to dentin hypersensitivity, dentin disks were treated with EDTA for 2 min. The disks were treated with 0.476 mol/L SiF for 3 min, and then the disks were immersed in synthetic saliva, which was regularly replenished to maintain its ionic concentration, for up to 7 days. The occluding ability of the dentin tubules was evaluated using scanning electron microscopy (SEM), and the hydraulic conductance was measured following Pashley's method at regular intervals.
SEM photographs demonstrated that dentin tubules were occluded homogeneously and completely with the precipitate at 7 days after treatment with SiF. In addition, newly formed calcium phosphate precipitate was present at the dentin surface. The dentin permeability showed a consistently low value throughout the experimental period. The values immediately after SiF treatment and 7 days after immersion were 11.9+/-3.7% and 7.9+/-2.9%, respectively.
Ammonium hexafluorosilicate is useful for the treatment of dentin hypersensitivity, since ammonium hexafluorosilicate induced calcium phosphate precipitation from the saliva; therefore, it has a continuous effect on dentin tubules occlusion under a simulated oral environment.
氟化二胺银[AgF:(NH(3))(2)AgF]在日本已用于临床，因为它可减少龋齿和牙本质过敏。然而，由于银沉淀，AgF会使牙齿变黑。为克服这一缺点，作者制备了不会使牙齿染色的六氟硅酸铵[SiF:(NH(4))(2)SiF(6)]，并且SiF会用硅-磷酸钙沉淀物完全封闭开放的牙本质小管。
本研究的目的是在模拟口腔环境中评估SiF治疗后牙本质小管封闭的持续时间。
为模拟患有牙本质过敏的牙本质小管，用乙二胺四乙酸（EDTA）处理牙本质盘2分钟。将牙本质盘用0.476mol/L的SiF处理3分钟，然后将牙本质盘浸入人工唾液中长达7天，人工唾液会定期补充以维持其离子浓度。使用扫描电子显微镜（SEM）评估牙本质小管的封闭能力，并按照帕什利方法定期测量水力传导率。
SEM照片显示，用SiF处理7天后，牙本质小管被沉淀物均匀且完全地封闭。此外，在牙本质表面存在新形成的磷酸钙沉淀物。在整个实验期间，牙本质通透性始终显示为低值。SiF处理后立即测量的值以及浸入7天后的值分别为11.9±3.7%和7.9±2.9%。
六氟硅酸铵可用于治疗牙本质过敏，因为六氟硅酸铵可诱导唾液中磷酸钙沉淀；因此，在模拟口腔环境下，它对牙本质小管封闭具有持续作用。
