Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Building 73, Saarland University, D-66421 Homburg, Germany.
Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, D-85354 Freising, Germany.
J Dent. 2017 Aug;63:21-29. doi: 10.1016/j.jdent.2017.05.011. Epub 2017 Jun 12.
This electron microscopic study aimed at investigating effects of oral astringent stimuli on the enamel pellicle's morphology.
Pellicles were formed in situ within 30min on bovine enamel slabs, fixed to individuals' upper jaw splints. The pellicle-coated specimens were immersed in vitro in seven diverse astringent solutions and subsequently analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, as well as transmission electron microscopy (TEM). Four biocompatible astringents, namely the polyphenol epigallocatechin gallate, the metal salt iron(III) sulfate, the basic protein lysozyme, and the aminopolysaccharide chitosan, were additionally applied in situ. After rinsing the oral cavity with these compounds, the pellicle's ultrastructure was imaged by SEM and TEM, respectively. Untreated pellicle samples served as controls.
Exposure to polyphenols and lysozyme induced particularly thicker and electron-denser pellicles in comparison to the control pellicle with similar characteristics in vitro and in situ. In contrast, acidic chitosan and metal salt solutions, respectively, revealed minor pellicle alterations. The incorporation of Fe and Al into the pellicles treated with the corresponding inorganic salts was verified by EDX analysis.
Astringent-induced pellicle modifications were for the first time visualized by TEM. The ultrastructural alterations of the dental pellicle may partly explain the tooth-roughening effect caused by oral astringent stimuli.
Astringents might modify the pellicle's protective properties against dental erosion, attrition, as well as bacterial adhesion, and by this means may influence tooth health. The findings may thus be particularly relevant for preventive dentistry.
本电子显微镜研究旨在调查口腔收敛刺激对牙釉质获得性膜形态的影响。
在 30 分钟内在牛牙釉质片上原位形成获得性膜，将获得性膜包被的标本固定在上颌夹板上。将包被有获得性膜的标本在体外浸入七种不同的收敛溶液中，然后用扫描电子显微镜（SEM）、能量色散 X 射线（EDX）光谱仪以及透射电子显微镜（TEM）进行分析。另外还将四种生物相容性收敛剂，即多酚表没食子儿茶素没食子酸酯、金属盐硫酸铁（III）、碱性蛋白溶菌酶和氨基多糖壳聚糖，在体内应用。用这些化合物漱口后，分别用 SEM 和 TEM 对获得性膜的超微结构进行成像，未处理的获得性膜样本作为对照。
与对照获得性膜相比，多酚和溶菌酶暴露导致获得性膜更厚，电子密度更高，体外和体内具有相似的特征。相比之下，酸性壳聚糖和金属盐溶液分别导致获得性膜的轻微改变。通过 EDX 分析证实了用相应无机盐处理的获得性膜中 Fe 和 Al 的掺入。
收敛剂诱导的获得性膜改变首次通过 TEM 可视化。牙获得性膜的超微结构改变可能部分解释了口腔收敛刺激引起的牙齿粗糙化效应。
收敛剂可能会改变获得性膜对牙齿酸蚀、磨损以及细菌黏附的保护特性，从而影响牙齿健康。因此，这些发现可能对预防牙科具有特别重要的意义。
