Mohammed Nasrine R, Lynch Richard J M, Anderson Paul
Barts and The London School of Medicine and Dentistry, Queen Mary University, Dental Physical Sciences Unit, Centre for Oral Growth and Development, London E1 4NS, United Kingdom.
GlaxoSmithKline Consumer Healthcare, St. George's Avenue, Weybridge, Surrey KT13 0DE, United Kingdom.
J Dent. 2014 May;42(5):613-8. doi: 10.1016/j.jdent.2013.12.005. Epub 2013 Dec 25.
The aim of the present study was to measure the effects of fluoride concentration on the real-time in vitro demineralization of enamel during exposure to caries-simulating conditions using Scanning Microradiography (SMR).
Enamel blocks obtained from non-carious human molars were fixed in SMR environmental cells, through which acidic solutions (0.1M acetic acid, pH 4.0) were circulated for periods of 48h. SMR was used to quantitatively measure continuous mineral mass loss. Subsequently, the effects of sequentially increasing fluoride concentration (0.1-4500mg/L [F(-)]) in the acidic solutions were measured on the rate of enamel demineralization.
The data shows a log-linear relationship between [F(-)] and reduction in demineralization up to 135mg/L [F(-)]. Above 135mg/L, no further significant decrease in demineralization occurred.
The optimum range of local fluoride concentration for reducing enamel demineralization was in the range 0.1-135mg/L [F(-)] under the conditions studied.
Relatively low [F(-)] can exhibit near-optimum protection. Increasing the fluoride concentrations above 135mg/L may not necessarily give an increased cariostatic benefit. Improving the means of delivery of relatively low fluoride concentrations to the oral fluids through slow releasing mechanisms, such as the oral fluoride reservoirs, is the more appropriate way forward for sustaining long-term clinical efficacy.
本研究的目的是使用扫描显微放射成像技术（SMR），测量在模拟龋齿条件下氟化物浓度对牙釉质实时体外脱矿的影响。
从无龋人类磨牙获取的牙釉质块固定于SMR环境池中，酸性溶液（0.1M乙酸，pH 4.0）在其中循环48小时。使用SMR定量测量连续的矿物质质量损失。随后，测量酸性溶液中依次增加的氟化物浓度（0.1 - 4500mg/L [F(-)]）对牙釉质脱矿速率的影响。
数据显示，在氟化物浓度达到135mg/L [F(-)]之前，[F(-)]与脱矿减少之间呈对数线性关系。高于135mg/L时，脱矿不再有进一步显著降低。
在所研究的条件下，减少牙釉质脱矿的局部氟化物浓度最佳范围为0.1 - 135mg/L [F(-)]。
相对低的[F(-)]可表现出近乎最佳的保护作用。将氟化物浓度提高到135mg/L以上不一定能增加防龋益处。通过缓释机制（如口腔氟化物储存器）改善向口腔液体输送相对低氟化物浓度的方式，是维持长期临床疗效更合适的前进方向。
