比較計時安培法及微分脈衝伏安法對於氟離子進入牙釉質深度以及抗酸之研究

Abstract

氟離子電導入法 (fluoride iontophoresis, FI)，早先已有學者Siemon和Manning提出NaF的離子電導入法，利用電壓推動氟離子深入牙本質小管，以達成CaF2的沉澱，減少牙本質小管內的液體流動，進而達到降低牙本質敏感的效果。本實驗即以電化學為概念的離子電導入法，希望將氟離子導入至牙齒較深處的位置，延長氟化物結構存在於牙齒的時間。良好的氟離子導入裝置必須是能在最短的時間內，達成最有效的氟化合物的形成且能停留在牙齒的時間較久。目前臨床所使用的FI device (Pyo-cure, Narcohm, Japan)的電化學條件為計時安培法(Chronoamperometry，CA)，且氟離子導入的深度卻很有限，進而會影響其使用後的成效，本實驗想以不同微分脈衝伏安法(Differential-Pulse Voltammetry, DPV)的電化學條件與市售裝置來做比較。 由X射線電子能譜儀 (XPS)分析牙釉質縱切面之F和Ca，計算出F/Ca+F ratio。結果以DPV(OCV0.005S-10V0.02S)、DPV(OCV0.005s-10V0.005s)及DPV(OCV0.02S-10V0.005S) 之數值最高。並且由XPS分析在Ca 2p3/2及F 1s之spectra比較圖可以推測經過電化學處理後之牙釉質縱切點A、B、C、D其主要沉積物的結構推測是fluorapatite (FAP)。配合pH Cycling及離子層析儀 (IC)分析鈣離子流失和吸收量及牙釉質抗蛀牙的能力，發現F/Ca+F ratio值愈高的組別其可抵抗牙釉質去礦化、增強再礦化。 綜合實驗所有的結果顯示，使用DPV電化學條件，在抵抗牙釉質去礦化、增強再礦化方面的能力是比較好的，在預防齲齒上應具備良好的應用價值。

The experiment of fluoride iontophoresis has been suggested by Siemon and Manning earlier. They adopted NaF iontophoresis to import fluorides into dentinal tubules by electric voltage. The fluid movement in dentinal tubules were reduced by precipitation of CaF2 in tubules. Therefore, dentin hypersensitivity will be decreased. The experiment used iontophoresis based on the concept of electrochemistry to import fluorides into the inner part of the teeth. The duration that fluorine compounds in the teeth is expected to be prolonged. A well-designed fluoride iontophoresis should produce fluorine compounds effectively and efficiently. The fluorine compounds should be able to stay in the teeth for a longer duration. The electrochemistry approach of current clinical FI device (Pyo-cure, Narcohm, Japan) is Chronoamperometry. Fluorides is imported to a limited degree, which affects the outcome of the experiment. In this experiment, we used differential-pulse voltammetry to increase the depth of fluorine compounds in a limited time. Thus, the decomposition of fluorine compounds in the oral environment is expected to be reduced.The experiment aims to compare differential-pulse voltammetry with chronoamperometry, which is adopted by current clinical devices. The ratio of F/Ca+F was calculated through analyzing the F-and Ca2+ on the longitudinal section of enamel with X-ray Photoelectron Spectroscopy (XPS). The highest values were DPV(OCV0.005S-10V0.02S), DPV(OCV0.005S-10V0.005S), and DPV(OCV0.02S-10V0.005S). With the spectra of the XPS analysis of the Ca 2p3/2 and F 1s, we found that the main structure of the compound in enamel section A, B, C, and D is FAP. By analyzing the loss and uptake of Ca2+ with pH Cycling and IC, it was found that the groups with a higher F/Ca+F ratio demonstrated higher resistance against demineralization and enforcing remineralization. In conclusions, DPV is more effective in resisting the demineralization and enforcing the remineralization of enamel.