BACKGROUND Dentin hypersensitivity is a frequent finding especially in periodontitis patients. Conventional treatment aims for obstruction of dentin tubules by disabling liquid and osmotic fluctuation to and from the pulpal chamber. A novel bioglass-based desensitizer was shown to obstruct tubules and to resist periodic exposure to lactic acid. Whether this obstruction is resistant to brushing had not been tested so far. Accordingly, the present study aimed to assess dentin tubule obstruction after repeated acid exposure and brushing. METHODS Sixty dentin discs were cleaned with 17% EDTA, mounted into a pulp fluid simulator and randomly divided into 3 groups: No surface treatment in Group A, Seal&Protect® in group B and DentinoCer in group C. Discs were exposed to 0.1 M non-saturated lactic acid thrice and standardized brushing twice a day for 12 days. At baseline and after 2, 4 and 12 d samples were removed from the setting and prepared for top-view SEM analysis to assess tubule obstruction using the Olley score. Discs were then vertically cut and the section surface morphologically assessed using backscatter imaging. For both vertical and sectional surfaces EDX analysis was used to characterize the surface composition in the tubular and inter-tubular area. RESULTS Group A showed clean tubular lumina at all time points. From day 2 onwards dentin showed exposed collagen fibers. Group 2 initially showed a complete surface coverage that flattened out during treatment without ever exposing tubules. At baseline, samples of Group C displayed a complete homogeneous coverage. From day 2 on tubules entrances with obstructed lumen became visible. While on day 4 and 12 the dentin surface exposed collagen fibers the lumina remained closed. EDX analysis of the vertical and horizontal views showed that P and Ca were predominant elements in both the inter- and tubular dentin while Si peaks were found in the tubule plugs. CONCLUSION While group B displayed a packed layer on the surface during the whole investigation time group C samples lost their superficial layer within 48 h. Tubule plugs containing considerable Si proportions indicated previous presence of DentinoCer, while high Ca and P proportions suggest obturation by dentin-like material.

中文翻译：

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在反复暴露于乳酸和刷牙的情况下，基于生物玻璃的牙本质脱敏剂的牙本质小管阻塞。

背景技术牙本质过敏症是经常发现的，尤其是在牙周炎患者中。常规治疗的目的是通过使牙髓腔内的液体和渗透性波动无效来阻塞牙本质小管。一种新型的基于生物玻璃的脱敏剂被证明可阻塞肾小管并抵抗定期暴露于乳酸中。到目前为止，还没有测试过这种阻塞是否能抵抗刷牙。因此，本研究旨在评估反复酸暴露和刷牙后牙本质小管阻塞的情况。方法用17％EDTA清洁60颗牙本质牙盘，将其安装在纸浆流体模拟器中并随机分为3组：A组无表面处理，B组为Seal＆Protect®和C组为DentinoCer。将光盘暴露于0。1 M非饱和乳酸三次，每天两次标准刷牙，共12天。在基线以及第2、4和12 d后，将样品从环境中取出，并准备进行顶视图SEM分析，以使用Olley评分评估小管阻塞。然后将圆盘垂直切割，并使用反向散射成像对截面表面进行形态学评估。对于垂直表面和截面表面，都使用EDX分析来表征管状和管状间区域的表面成分。结果A组在所有时间点均显示清洁的管状腔体。从第2天开始，牙本质显示出暴露的胶原纤维。第2组最初显示出完整的表面覆盖范围，在治疗期间变平而从未暴露过小管。基线时，C组样本显示出完全均匀的覆盖率。从第2天开始，在肾小管上可见管腔阻塞的入口。当在第4天和第12天，牙本质表面暴露的胶原纤维时，管腔保持闭合。EDX对垂直和水平视图的分析表明，在牙本质间和管状牙本质中，P和Ca是主要元素，而在小管塞中发现了Si峰。结论在整个研究期间，B组在表面上都显示出一层填充层，而C组样品在48小时内失去了表层。含有大量硅含量的小管塞表明以前存在DentinoCer，而高钙和磷含量表明被牙本质样物质阻塞。EDX对垂直和水平视图的分析表明，在牙本质间和管状牙本质中，P和Ca是主要元素，而在小管塞中发现了Si峰。结论在整个研究期间，B组在表面上都显示出一层填充层，而C组样品在48小时内失去了表层。含有大量硅含量的小管塞表明以前存在DentinoCer，而高钙和磷含量表明被牙本质样物质阻塞。EDX对垂直和水平视图的分析表明，在牙本质间和管状牙本质中，P和Ca是主要元素，而在小管塞中发现了Si峰。结论在整个研究期间，B组在表面上都显示出一层填充层，而C组样品在48小时内失去了表层。含有大量硅含量的小管塞表明以前存在DentinoCer，而高钙和磷含量表明被牙本质样物质阻塞。