Piracicaba Dental School, UNICAMP, Piracicaba, SP, Brazil.
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Int J Paediatr Dent. 2017 Nov;27(6):496-505. doi: 10.1111/ipd.12288. Epub 2017 Jan 30.
Storage time may reduce the amount of soluble fluoride (F) in toothpastes. Although we previously studied the type and concentration of F in fresh samples of commercial Chilean toothpastes, their stability was not determined.
To evaluate the stability of soluble F in Chilean toothpastes after 1 year of storage.
All the toothpastes (n = 30) previously used were re-analyzed after 1 year of storage time at room temperature (±22°C). Total F (TF = soluble F + insoluble F) and total soluble F (TSF = F ion + MFP ion) were assessed using an ion-specific electrode, through a validated methodology. Data were expressed in ppm of F (mg F/kg).
Mean (±SD; n = 30) TF and TSF concentrations after storage were 1049 ± 427 and 987 ± 411 ppm F, respectively. Five toothpastes showed between 30% and 50% of insoluble F, four of them formulated with MFP/calcium-based abrasive. In two products, there was a reduction in TSF below the evidence-based anticaries effectiveness threshold of 1000 ppm F.
Although most of the toothpastes tested kept their original TSF content after 1 year of storage, some products evidenced an important reduction, which may compromise their anticaries efficacy. Reductions in TSF may be explained by an incorrect F salt-abrasive formulation.
储存时间可能会降低牙膏中可溶性氟（F）的含量。尽管我们之前研究了智利市售牙膏新鲜样本中的 F 类型和浓度，但并未确定其稳定性。
评估智利牙膏中可溶性 F 在储存 1 年后的稳定性。
所有之前使用过的牙膏（n=30）在室温（±22°C）下储存 1 年后重新进行分析。采用离子特异性电极和经验证的方法评估总氟（TF=可溶性 F+不溶性 F）和总可溶性 F（TSF=F 离子+MFP 离子）。数据以 F 的 ppm（mg F/kg）表示。
储存后 TF 和 TSF 的平均（±SD；n=30）浓度分别为 1049±427 ppm 和 987±411 ppm F。5 种牙膏的不溶性 F 含量在 30%至 50%之间，其中 4 种含有 MFP/钙基磨料。在两种产品中，TSF 降低到 1000 ppm F 的抗龋有效阈值以下。
尽管大多数测试的牙膏在储存 1 年后仍保持其原始的 TSF 含量，但有些产品的 TSF 含量明显降低，这可能会影响其抗龋效果。TSF 的降低可能是由于 F 盐-磨料配方不正确所致。
