Barbour M E, Parker D M, Allen G C, Jandt K D
Department of Oral and Dental Science, University of Bristol, Bristol, UK.
J Oral Rehabil. 2005 Jan;32(1):16-21. doi: 10.1111/j.1365-2842.2004.01365.x.
The objective of this study was to investigate human enamel erosion under constant composition conditions, as a function of solution degree of saturation (DS) with respect to hydroxyapatite. The experimental conditions were relevant to the initial stages of enamel erosion by soft drinks. Nanoindentation was used to compare enamel surface softening caused by a control mineral water and two citric acid solutions with DS = 0.000 and DS = 0.032, both having pH 3.30. Enamel hardness and reduced elastic modulus were measured after 0, 30, 60, 120, 300 and 600 s exposure. A statistically significant change in enamel hardness was detected after 30 s exposure to both citric acid solutions, indicating that nanoindentation is extremely sensitive to the initial stages of erosion. There was a statistically significant difference between the mechanical properties of enamel exposed to the two citric acid solutions after 30, 60 and 120 s. At these times, the solution with DS = 0.000 caused twice as much enamel softening as that with DS = 0.032. This demonstrates that it may be possible to design a soft drink with a low erosive potential and a good taste by a small change in DS, at a typical drink pH.
本研究的目的是在恒定成分条件下，研究人类牙釉质侵蚀情况，作为溶液相对于羟基磷灰石的饱和度（DS）的函数。实验条件与软饮料对牙釉质侵蚀的初始阶段相关。使用纳米压痕法比较由对照矿泉水和两种DS分别为0.000和0.032的柠檬酸溶液引起的牙釉质表面软化情况，这两种溶液的pH值均为3.30。在暴露0、30、60、120、300和600秒后测量牙釉质硬度和折合弹性模量。暴露于两种柠檬酸溶液30秒后，检测到牙釉质硬度有统计学上的显著变化，表明纳米压痕法对侵蚀的初始阶段极其敏感。暴露于两种柠檬酸溶液30、60和120秒后，牙釉质的力学性能存在统计学上的显著差异。在这些时间点，DS = 0.000的溶液导致的牙釉质软化程度是DS = 0.032溶液的两倍。这表明，在典型的饮料pH值下，通过对DS进行微小改变，有可能设计出一种具有低侵蚀潜力且口感良好的软饮料。
