鈣離子濃度梯度對於牙釉質酸蝕之影響：體外實驗

Effect of Concentration Gradient of Calcium Ion on Enamel Erosion： An in vitro Study

余思嫺(Szu-Hsien Yu)

指導教授 ： 林俊彬

國立臺灣大學/牙醫專業學院/臨床牙醫學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.00520

摘要

目的：牙齒酸蝕問題隨盛行率上升日益受到重視，過去文獻指出在軟性飲料中添加鈣離子能有效降低其酸蝕潛能。本實驗目的在於以體外實驗探討不同酸度下鈣離子濃度梯度對於降低牙釉質酸蝕程度的影響。
材料與方法：使用鹽酸當作酸性來源，並以氫氧化鈉滴定成pH 2.5、pH 3、pH 5.5三種酸度，分別調配成鈣離子濃度為1 M、0.1 M、10-2 M、10-3 M、10-4 M、10-5 M、10-6 M等七種濃度的含鈣溶液，與一組不含鈣者當成實驗對照組，總共24組，共使用72片人類牙釉質樣本。樣本浸泡溶液3分鐘後，以感應耦合電漿質譜儀分析溶液內磷離子含量、以維氏微小硬度計測量樣本表面硬度變化、使用雷射掃描共軛焦顯微鏡以及電子掃描顯微鏡觀察表面影像。
結果：在pH 3以及pH 5.5下鈣離子濃度1 M的組別，溶液中沒有檢出磷析出。在各組pH值下，添加鈣離子能有效降低牙釉質表面硬度下降量。pH 2.5下鈣離子濃度為10-5M與10-6M組可觀察到實驗區與對照區明顯高度落差。
結論：在酸性溶液中添加一定濃度的鈣離子，能有效降低酸性環境對牙釉質所造成的影響。隨著pH值下降，要達到有效降低酸蝕影響，需添加更高濃度的鈣離子。溶液pH值大於3，添加鈣離子濃度1 M時，在溶液中無法測得磷元素。pH 5.5以下的溶液，鈣離子含量小於1 M的各組，皆會使牙釉質表面硬度下降。檢出磷離子析出、表面硬度下降、表面粗糙度改變，三者不一定會同時發生，三者關係需進一步實驗釐清。

關鍵字

牙齒酸蝕 ； 鈣離子 ； 濃度梯度 ； 牙釉質 ； 感應耦合電漿質譜儀

並列摘要

Objectives: With the rising prevalence, dental erosion gradually becomes seriously taken. The aim of this study was to evaluate the effect of concentration gradient of calcium ion on dental erosion in vitro.
Materials and methods: HCl was chosen as acid source in the present study. The pH value was adjusted by NaOH to pH values of 2.5, 3 and 5.5. Calcium chloride dehydrate was added to the former solutions to achieve a calcium concentration of 1 M, 0.1 M, 0.01 M, 10-3 M, 10-4 M, 10-5 M, 10-6 M and 0 M. Seventy two enamel discs made of human extracted teeth were divided into 24 groups. Each enamel samples was then exposed to 30 ml of the appropriate solution for 3 minutes individually. After the exposure, the solution was tested by ICP-MS to detect the concentration of phosphorus and the samples were rinsed in gently running distilled water for 30 seconds. The samples were then analyzed of surface hardness change and surface structure by confocal laser scanning microscope, Vickers’ hardness tester and electronic scanning microscope.
Results: At pH 3 and pH 5.5, the addition of 1 M calcium resulted in no detection of phosphorus in the solution. At each of the pH values, the addition of calcium ion significantly decreased the amount of surface hardness loss. At pH 2.5, with 10-5 M and 10-6 M calcium, there was a significant difference between eroded area and the control area.
Conclusion: By adding a particular amount of calcium to acid, the acid showed less effect on enamel samples. With a pH value lower than 5.5, surface hardness loss would take place in spite of adding high concentration (1 M) of calcium.

並列關鍵字

dental erosion ； concentration gradient ； calcium ； dental enamel ； inductively coupled plasma mass spectrometer

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