Field James, German Matthew, Waterhouse Paula
Restorative Dentistry, Newcastle University School of Dental Sciences, United Kingdom.
J Dent. 2013 Nov;41(11):1060-7. doi: 10.1016/j.jdent.2013.08.015. Epub 2013 Aug 30.
Most in vitro studies investigate the erosive process using relatively simple roughness parameters such as roughness average (Ra). In isolation, Ra may misrepresent the surface features. Further, few studies report baseline surface characteristics after sample preparation. This study aimed to test the hypothesis that measuring the bearing area parameters in addition to Ra may be useful when qualifying the surface of enamel at baseline and after an erosive challenge. The null hypothesis for this study was that the bearing area parameters provide no more useful information than Ra alone, when qualifying the surface of enamel at baseline and after an erosive challenge.
Enamel slabs (n=20) were prepared from human (n=2) and bovine (n=4) incisor teeth and polished with 0.05μm paste. Roughness average (Ra) and bearing parameters (MR1, MR2, Rpk, Rk, Rvk) were used to record baseline characteristics. Specimens were subjected to erosion with 1% citric acid solution for 1min. Profilometric characteristics were recorded post-erosion, along with the maximum height changes within the profile. T-tests were carried out in order to compare baseline surface characteristics between tissue types. Post-erosion, analysis of variance (ANOVA) was used to test the effects of tissue type (bovine or human).
There was no significant difference in Ra between human and bovine incisor enamel at baseline (human 0.11μm, bovine 0.12μm P>0.05), and no significant difference was observed post-erosion (human 0.23μm, bovine 0.20μm P>0.05). There were significant differences in bearing parameters at baseline and post-erosion that were not identified by the Ra measurement alone.
The results suggest that if Ra alone is measured, important differences in surface characteristics may be missed. The null hypothesis is rejected, and the recommendation is made that bearing parameters are included within profile measurements in order to further triangulate the results of surface analysis studies.
In isolation, Ra may misrepresent the surface features of a profile. These results have shown that the bearing parameters are an important and informative set of measurements. The recommendation is made that bearing parameters are included within profile measurements at baseline and post-erosion, in order to further triangulate the results of surface analysis studies.
大多数体外研究使用相对简单的粗糙度参数（如平均粗糙度（Ra））来研究侵蚀过程。单独来看，Ra可能无法准确反映表面特征。此外，很少有研究报告样本制备后的基线表面特征。本研究旨在检验以下假设：在对牙釉质表面进行基线评估和侵蚀挑战后进行评估时，除了测量Ra外，测量承载面积参数可能会有所帮助。本研究的零假设是，在对牙釉质表面进行基线评估和侵蚀挑战后进行评估时，承载面积参数不会比单独的Ra提供更多有用信息。
从人（n = 2）和牛（n = 4）的切牙制备牙釉质片（n = 20），并用0.05μm的糊剂进行抛光。使用平均粗糙度（Ra）和承载参数（MR1、MR2、Rpk、Rk、Rvk）记录基线特征。将样本用1%的柠檬酸溶液侵蚀1分钟。侵蚀后记录轮廓测量特征以及轮廓内的最大高度变化。进行t检验以比较不同组织类型之间的基线表面特征。侵蚀后，使用方差分析（ANOVA）来检验组织类型（牛或人）的影响。
人牙和牛牙切牙釉质在基线时的Ra无显著差异（人0.11μm，牛0.12μm，P>0.05），侵蚀后也未观察到显著差异（人0.23μm，牛0.20μm，P>0.05）。在基线和侵蚀后，承载参数存在显著差异，而单独的Ra测量未识别出这些差异。
结果表明，如果仅测量Ra，可能会错过表面特征的重要差异。零假设被拒绝，建议在轮廓测量中纳入承载参数，以便进一步确定表面分析研究的结果。
单独来看，Ra可能无法准确反映轮廓的表面特征。这些结果表明，承载参数是一组重要且信息丰富的测量值。建议在基线和侵蚀后进行轮廓测量时纳入承载参数，以便进一步确定表面分析研究的结果。
