Indiana University School of Dentistry, Department of Cariology, Operative Dentistry and Dental Public Health, Oral Health Research Institute, Indianapolis, IN, USA.
Arch Oral Biol. 2017 Aug;80:217-221. doi: 10.1016/j.archoralbio.2017.04.022. Epub 2017 Apr 20.
The aim was to investigate the effects of fluoride, strontium, theobromine and their combinations on caries lesion rehardening and fluoridation (EFU) under pH cycling conditions.
Human enamel specimens were demineralized at 37°C for 24h using a pH 5.0 solution containing 50mM lactic acid and 0.2% Carbopol 907 which was 50% saturated with respect to hydroxyapatite. Lesions were assigned to nine treatment groups (n=16) based on Knoop surface microhardness indentation length.
aqueous solutions were: placebo, 11.9mM sodium fluoride (F), 23.8mM sodium fluoride (2×F), 1.1mM strontium chloride hexahydrate (Sr), 1.1mM F theobromine, Sr+theobromine, F+Sr, F+theobromine, F+Sr+theobromine. Lesions were pH cycled for 5d (daily protocol: 3×1min-treatment; 2×60min-demineralization; 4×60min & overnight-artificial saliva). Knoop indentation length was measured again and%surface microhardness recovery (%SMHr) calculated. EFU was determined using the acid-etch technique. Data were analysed using ANOVA.
Model showed fluoride dose-response for both variables (2×F>F>placebo). For%SMHr, F+Sr+/-theobromine resulted in more rehardening than F, however less than 2×F. F+theobromine was similar to F. For EFU, F+Sr was inferior to F, F+theobromine and F+Sr+theobromine which were similar and inferior to 2×F. In absence of fluoride, Sr, theobromine or Sr+theobromine were virtually indistinguishable from placebo and inferior to F.
It can be concluded that a) strontium aids rehardening but not EFU and only in presence of fluoride; b) theobromine does not appear to offer any anti-caries benefits in this model; c) there are no synergistic effects between strontium and theobromine in the presence or absence of fluoride.
研究氟化物、锶、可可碱及其组合在 pH 循环条件下对龋损再矿化和氟化物（EFU）的影响。
将人牙釉质标本在 37°C 下用 pH 5.0 的溶液脱矿 24 小时，该溶液含有 50mM 乳酸和 0.2% Carbopol 907，其相对于羟磷灰石的饱和度为 50%。根据 Knoop 表面显微硬度压痕长度，将病变分为 9 个治疗组（n=16）。
水溶液为：安慰剂、11.9mM 氟化钠（F）、23.8mM 氟化钠（2×F）、1.1mM 六水氯化锶（Sr）、1.1mM F 可可碱、Sr+可可碱、F+Sr、F+可可碱、F+Sr+可可碱。将病变 pH 循环 5 天（每日方案：3×1min-治疗；2×60min-脱矿；4×60min 和过夜-人工唾液）。再次测量 Knoop 压痕长度并计算%表面显微硬度恢复（%SMHr）。使用酸蚀技术测定 EFU。使用方差分析对数据进行分析。
模型显示两种变量的氟剂量反应（2×F>F>安慰剂）。对于%SMHr，F+Sr+/-可可碱的再矿化效果强于 F，但弱于 2×F。F+可可碱与 F 相似。对于 EFU，F+Sr 劣于 F、F+可可碱和 F+Sr+可可碱，它们相似且劣于 2×F。在没有氟化物、锶、可可碱或 Sr+可可碱的情况下，与安慰剂几乎没有区别，且劣于 F。
可以得出以下结论：a）锶有助于再矿化，但不能提高 EFU，并且仅在存在氟化物的情况下；b）在该模型中，可可碱似乎没有提供任何抗龋益处；c）在存在或不存在氟化物的情况下，锶和可可碱之间没有协同作用。
