Huang W-T, Anderson P, Duminis T, Shahid S
Institute of Dentistry, Queen Mary University of London, London, United Kingdom.
Institute of Dentistry, Queen Mary University of London, London, United Kingdom.
Dent Mater. 2022 Apr;38(4):709-714. doi: 10.1016/j.dental.2022.02.013. Epub 2022 Mar 4.
This study investigates the demineralization inhibitory mechanisms of AgNO, AgF and silver diamine fluoride (SDF) using a previously used hydroxyapatite (HAP) caries demineralization model system.
HAP discs were allocated into three groups (n = 3) and immersed in demineralization solution (buffered pH 4.0, 0.1 mol/L acetic acid) for 4 h. Each disc was treated topically with either 3.16 M AgNO, 3.16 M AgF or 3.16 M SDF using a micro-brush. The discs were then demineralized for a further 4 h. Calcium, silver, and fluoride ion selective electrodes (ISEs) were used to monitor the changes in each ion concentration at 1 min intervals throughout. Demineralization inhibition was calculated as the percentage reduction in the rate of calcium ion loss from HAP (PRCL). Characterization of similarly treated HAP powder was carried out with Magic Angle Spinning-Nuclear Magnetic Resonance RESULTS: The mean PRCL for each treatment group was; AgF (72.3 + 4.8%), SDF (69.7 + 5.3%) and AgNO (14.9 + 2.7%). AgPO was detected in all HAP powders. CaF and fluorohydroxyapatite (FHA) were detected only in powders treated with either AgF or SDF. The demineralization inhibitory efficacy of topically applied AgNO results from the formation of a AgPO barrier. Whereas, the demineralization inhibitory efficacy of topically applied AgF, and SDF, results from the formation of a barrier composed of AgPO, CaF, and FHA.
In addition to their anti-microbial properties, clinical topical application of silver compounds for caries preventative treatment is due to their ability to form acid-resistant barriers composed of silver phosphate. When fluoride is present, this barrier also contains CaF and FHA, additionally protecting the mineral.
本研究使用先前使用的羟基磷灰石（HAP）龋齿脱矿模型系统，研究硝酸银、氟化银和氟化氨银（SDF）的脱矿抑制机制。
将HAP圆盘分为三组（n = 3），并浸入脱矿溶液（缓冲pH 4.0，0.1 mol/L乙酸）中4小时。使用微型刷子对每个圆盘局部用3.16 M硝酸银、3.16 M氟化银或3.16 M SDF进行处理。然后将圆盘再脱矿4小时。使用钙、银和氟离子选择性电极（ISE）在整个过程中每隔1分钟监测每种离子浓度的变化。脱矿抑制率以HAP中钙离子损失率降低的百分比（PRCL）计算。对经类似处理的HAP粉末进行魔角旋转核磁共振表征。结果：每个治疗组的平均PRCL为；氟化银（72.3 + 4.8%）、SDF（69.7 + 5.3%）和硝酸银（14.9 + 2.7%）。在所有HAP粉末中均检测到磷酸银。仅在用氟化银或SDF处理的粉末中检测到氟化钙和氟羟基磷灰石（FHA）。局部应用硝酸银的脱矿抑制效果源于形成了磷酸银屏障。而局部应用氟化银和SDF的脱矿抑制效果源于形成了由磷酸银、氟化钙和FHA组成的屏障。
除了具有抗菌特性外，银化合物在临床局部应用于龋齿预防治疗是因为它们能够形成由磷酸银组成的耐酸屏障。当存在氟时，该屏障还包含氟化钙和FHA，进一步保护矿物质。
