Effect of Concentration Gradient of Calcium Ion on Enamel Erosion： An in vitro Study
Date Issued
2015
Date
2015
Author(s)
Yu, Szu-Hsien
Abstract
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.
Subjects
dental erosion
concentration gradient
calcium
dental enamel
inductively coupled plasma mass spectrometer
Type
thesis
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