The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion

Abstract This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey’s test; and Ra, by 2-way ANOVA, repeated measures, and Tukey’s test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

摘要 本研究评估了植物鞘氨醇（phytosphingosine, PHS）与生物活性玻璃陶瓷（bioactive glass-ceramic, Biosilicate）在酸蚀挑战（erosive challenge, EC）下对牙釉质的影响，评估指标涵盖颜色改变（色差值ΔE）、显微硬度及表面粗糙度。本研究共制备60颗牛牙标本（规格为6×6×2mm），首先完成初始颜色（采用Easyshade设备，VITA公司）、克氏硬度（Knoop hardness number, KHN，采用HMV-2设备，岛津Shimadzu公司）及表面粗糙度参数Ra（采用SJ-201P设备，三丰Mitutoyo公司）的检测。将标本按处理方式分为四组：植物鞘氨醇组、10%生物活性玻璃陶瓷组、植物鞘氨醇+10%生物活性玻璃陶瓷组，以及人工唾液对照组，随后将所有标本置于可口可乐中进行酸蚀挑战，每次持续2分钟。该循环每日重复4次，共计15天。两次循环之间，将标本置于37℃人工唾液中孵育2小时；每日循环结束后，标本同样储存在37℃的人工唾液中。后续完成最终的颜色、显微硬度及表面粗糙度检测。其中颜色与克氏硬度数据采用单因素方差分析（one-way ANOVA）结合Tukey检验进行统计分析；表面粗糙度Ra数据则采用双因素重复测量方差分析结合Tukey检验进行统计分析，检验水准设定为p<0.05。统计结果显示，唾液对照组+酸蚀挑战组的色差值ΔE最高（p<0.05）。经植物鞘氨醇处理的各组颜色改变程度均低于唾液对照组+酸蚀挑战组（p<0.05）。除对照组外，其余各组的平均色差值均高于50:50%可感知阈值（50:50%PT）与50:50%可接受阈值（50:50%AT）；对照组的平均色差值虽高于50:50%可感知阈值，但低于50:50%可接受阈值。生物活性玻璃陶瓷+酸蚀挑战组的相对显微硬度高于唾液对照组+酸蚀挑战组（p<0.05），但与植物鞘氨醇+酸蚀挑战组以及植物鞘氨醇+生物活性玻璃陶瓷+酸蚀挑战组无统计学差异。除对照组外，其余各组的牙釉质最终表面粗糙度均有所升高（p<0.05）。本研究结果表明，相较于人工唾液，生物活性玻璃陶瓷可更有效地预防侵蚀诱导的牙釉质矿物质丢失；无论是否联合生物活性玻璃陶瓷，植物鞘氨醇均展现出优于人工唾液的颜色稳定性。