Supplementary Material for: Design of Erosion/Abrasion Studies – Insights and Rational Concepts

In vitro and in situ studies modelling the wear of dental hard tissues due to erosion and abrasion are characterised by a high variation in study designs and experimental parameters. Based on a summary of the existing protocols, the present review aimed to describe and discuss the parameters which must be carefully considered in erosion-abrasion research, especially when it is intended to simulate clinical conditions. Experimental characteristics and parameters were retrieved from a total of 42 in vitro and 20 in situ studies. The key experimental characteristics included parameters of erosion (duration and pH) and abrasion (duration, kinds of toothbrush and toothpaste, brushing force, and time point) as well as co-factors (e.g. dental hard tissue). The majority of studies used models with alternating erosion/abrasion treatments intended to simulate clinical conditions, while other studies exaggerated clinical conditions intentionally, often using only a single erosion/abrasion treatment. Both in vitro and in situ models shared a high level of standardisation, but several studies showed a trend to severe erosion (e.g. >5 min/cycle) or extensive brushing (e.g. >100 brushing strokes/cycle) at a high frequency and repetition rate. Thus, studies often tend to produce a higher amount of wear than in the clinical situation, especially as modifying biological factors (e.g. the dilution of the erosive solution by saliva and the protective effect of the pellicle) cannot be simulated adequately. With respect to the existing models, it seems advisable to diminish duration and frequency of erosion and abrasion to more realistic clinical conditions when the everyday situation is to be simulated. Experimental parameters must be chosen with care to ensure that the problem is investigated in an appropriate mode at standardised conditions and with adequate measuring systems to allow prediction of clinical outcomes.

以牙体硬组织因侵蚀与磨耗产生的磨损为建模对象的体外（in vitro）及原位（in situ）研究，其研究设计与实验参数均存在较高异质性。本综述在梳理现有实验方案的基础上，旨在阐述并探讨侵蚀-磨耗研究中需审慎考量的各项参数，尤其是在模拟临床场景的研究中。研究共检索纳入42项体外研究与20项原位研究的实验特征及参数，关键实验特征涵盖侵蚀相关参数（时长与pH值）、磨耗相关参数（时长、牙刷与牙膏类型、刷牙力度及作用时点）以及混杂因素（如牙体硬组织）。多数研究采用交替进行侵蚀/磨耗处理的模型以模拟临床场景，而另有部分研究刻意放大临床条件，通常仅采用单次侵蚀/磨耗处理。体外与原位模型均具备较高的标准化程度，但部分研究呈现出高频率、高重复率下实施重度侵蚀（如每循环＞5分钟）或高强度刷牙（如每循环＞100次刷牙动作）的趋势。因此此类研究往往产生较临床实际更高水平的磨损，尤其是部分调节性生物学因素（如唾液对侵蚀溶液的稀释作用及牙面获得性膜的保护效应）无法得到充分模拟。针对现有模型，若需模拟日常临床场景，建议将侵蚀与磨耗的时长及频率调整至更符合真实临床的水平。需审慎选择实验参数，确保在标准化条件下以适宜方式开展相关研究，并采用恰当的测量系统，以实现对临床结局的预测。