The Procter & Gamble Company, Mason, OH, USA,
The Procter & Gamble Company, Mason, OH, USA.
Am J Dent. 2022 Apr;35(2):69-74.
To use non-inferiority statistical testing with simple microhardness measurements (SMH) as a prediction of potential erosive hard tissue damage of topical treatments on enamel.
Three independent experiments of a simple acid cycling demineralization (ACD) model were used to screen softening effects of various commercial beverages on dental enamel. The cycling model consists of six repeated exposures of enamel slabs with alternating treatments of artificial saliva over the course of 6 hours. After six repeated cycles, effects on surface microhardness were measured. Softening effects of beverages were evaluated using a statistical non-inferiority test of the positive control (water) and negative control (1% citric acid). To confirm whether softening effects as evaluated by a non-inferiority test translated to like differences in enamel erosion susceptibility, selected beverages then underwent more complex erosion cycling model (ECM) evaluation where enamel blocks were cycled with beverages (vs. historically established citric acid) and pooled saliva over a period of 5 days. The ECM also incorporated dentifrice treatments, sodium fluoride (NaF, Crest Cavity Protection, negative control) and a positive control stannous fluoride dentifrice (SnF₂, Crest Pro-Health Advanced), to confirm model performance against historically published results of in situ erosion protection benefits of SnF₂.
There was a spectrum of softening properties of 16 commercial beverages in the ACD test, ranging from a ΔSMH of -22.6 to -316 vs. baseline. Four beverages were evaluated further in ECM testing. Despite a measurable change in SMH, Sprite and beer treatments in the ACD passed the statistical non-inferiority test and both were evaluated in erosion cycling, showing no enamel surface loss. Vinegar (~5% acetic acid) and Gatorade also showed measurable changes in SMH in the ACD, but they failed statistical non-inferiority testing. Both beverages subsequently showed significant enamel tissue loss (erosion) in further erosion cycling testing. This combined set of data suggests that simple surface microhardness evaluation may be used as a proxy for potential erosion surface loss if properly quantified. SnF₂ dentifrice significantly reduced erosion from all erosive beverages with greater efficacy than NaF control dentifrice, consistent with prior clinical and in vitro evidence.
The ACD model with application of non-inferiority statistical testing is proposed as a simple model of hard tissue safety assessment of treatments, including oral hygiene products. Products that pass the non-inferiority test in ACD (surface softening) are proposed as safe for enamel as there is no suggestion from this data that teeth are at risk of tissue loss due to these products. On the other hand, products failing the non-inferiority test require confirmatory safety qualification in erosion cycling. Products equal or worse than citric acid with ACD or with significant erosion in ECM are suggested to warrant reformulation unless favorable safety data for enamel (lack of erosion) or the appropriate justification are provided.
使用非劣效性统计检验和简单的显微硬度测量（SMH）来预测局部治疗对牙釉质潜在侵蚀性硬组织损伤的可能性。
使用简单的酸循环脱矿（ACD）模型的三个独立实验来筛选各种商业饮料对牙釉质的软化作用。该循环模型由六个重复暴露牙釉质平板组成，在 6 小时的过程中交替进行人工唾液处理。经过六次重复循环后，测量表面显微硬度的变化。使用阳性对照（水）和阴性对照（1%柠檬酸）的非劣效性检验来评估饮料的软化作用。为了确认非劣效性检验评估的软化作用是否与牙釉质侵蚀敏感性的相似差异有关，然后对选定的饮料进行更复杂的侵蚀循环模型（ECM）评估，其中牙釉质块在 5 天的时间内与饮料（与历史上确立的柠檬酸）和混合唾液一起循环。该 ECM 还包括牙膏处理、氟化钠（Crest Cavity Protection，阴性对照）和阳性对照单氟磷酸钠牙膏（Crest Pro-Health Advanced），以确认模型对 SnF₂体内防蚀益处的历史发布结果的性能。
在 ACD 测试中，16 种商业饮料的软化性能呈谱状，范围从相对于基线的-22.6 到-316ΔSMH。在 ECM 测试中进一步评估了四种饮料。尽管在 SMH 上有可测量的变化，但雪碧和啤酒处理在 ACD 中通过了非劣效性检验，并在侵蚀循环中进行了评估，未发现牙釉质表面损失。醋（约 5%醋酸）和佳得乐也在 ACD 中显示出可测量的 SMH 变化，但它们未通过非劣效性检验。这两种饮料随后在进一步的侵蚀循环测试中都显示出明显的牙组织损失（侵蚀）。这组综合数据表明，如果正确量化，简单的表面显微硬度评估可作为潜在侵蚀表面损失的替代指标。SnF₂牙膏显著减少了所有侵蚀性饮料的侵蚀，其效果优于氟化钠对照牙膏，与先前的临床和体外证据一致。
提出了一种简单的硬组织安全性评估模型，即应用非劣效性统计检验的 ACD 模型，用于治疗方法，包括口腔卫生产品。在 ACD 中通过非劣效性检验（表面软化）的产品被认为对牙釉质是安全的，因为从这些数据中没有迹象表明牙齿有因这些产品而导致组织损失的风险。另一方面，在 ACD 中未通过非劣效性检验或在 ECM 中具有侵蚀性的产品需要进行确证性安全性资格认证。具有 ACD 或在 ECM 中与柠檬酸相当或更差且具有显著侵蚀性的产品被建议进行重新配方，除非提供了牙釉质的有利安全性数据（无侵蚀）或适当的理由。
