Department of Prosthodontics, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Caries Res. 2009;43(6):449-54. doi: 10.1159/000261415. Epub 2009 Nov 25.
Recent experimental in vivo studies have shown that aqueous solutions of stannous fluoride (SnF(2)) and hydrofluoric acid (HF) can reduce enamel solubility after 5 min. The aim of this study was to evaluate the longer-term protective effect of SnF(2) (0.78%, pH 2.9) and HF (0.2%, pH 2.0) (both approximately 0.1 mol/l F) using the same experimental model. Labial surfaces of healthy anterior teeth (all four surfaces when possible, otherwise a pair of surfaces) in 103 subjects (n = 399 teeth) were exposed to citric acid (0.01 mol/l, pH 2.7). The acid was applied using a peristaltic pump (5 ml, 6 ml/min) and was collected in coded test tubes (etch I). The test solutions were then applied to the same surfaces of the teeth (1 min, 6 ml/min). After either 1, 7, 14 or 28 days, citric acid was again applied to the same surfaces and subsequently collected (etch II). Enamel solubility was examined by assessment of calcium concentration in etch I and etch II solutions using atom absorption spectroscopy. Median values were calculated for all time periods and statistical analysis was carried out using the Wilcoxon signed-ranks test. Results showed that HF reduced enamel solubility by 54 and 36% after 1 and 7 days, respectively. After 14 and 28 days, there was no longer any effect. SnF(2) showed no protective effect after the first day. Given these results, repeated application of HF and especially SnF(2) may be necessary to improve the protective effect of these fluorides, and this requires further testing.
近期的体内实验研究表明，氟化亚锡（SnF2）和氢氟酸（HF）的水溶液在 5 分钟后可降低牙釉质的溶解度。本研究旨在使用相同的实验模型评估 SnF2（0.78%，pH 值 2.9）和 HF（0.2%，pH 值 2.0）（两者的氟浓度约为 0.1mol/L）的长期保护效果。将 103 名受试者（n=399 颗牙）的健康前牙唇面（尽可能为所有四个面，否则为一对面）暴露于柠檬酸（0.01mol/L，pH 值 2.7）中。使用蠕动泵（5ml，6ml/min）将酸液施加到牙齿表面，并将收集在编码试管中（蚀刻 I）。然后将测试溶液施加到牙齿的相同表面（1 分钟，6ml/min）。1、7、14 或 28 天后，再次将柠檬酸施加到相同表面并随后收集（蚀刻 II）。通过原子吸收光谱法评估蚀刻 I 和蚀刻 II 溶液中的钙浓度来检查牙釉质的溶解度。计算了所有时间段的中位数，并使用 Wilcoxon 符号秩检验进行了统计分析。结果表明，HF 在第 1 天和第 7 天分别降低了牙釉质的溶解度 54%和 36%。14 天和 28 天后，不再有任何效果。SnF2 在第一天没有保护作用。鉴于这些结果，可能需要重复应用 HF 和特别是 SnF2，以提高这些氟化物的保护效果，这需要进一步的测试。
