[上图]将万圣节巧克力留在牙齿上的时间太长会导致牙齿腐烂 - 我们最终可以通过种植新的搪瓷来修复牙齿吗？信用：史蒂文·德波洛（Steven Depolo）, Flickr (CC BY 2.0)
我们现在是一个（联合国）幸运的距离万圣节和Díade los Muertos庆祝活动的开端13天，从全国各地的糖果26亿美元.
便宜的糖果是主食（和祸根) of Halloween handouts. And as much as you like eating it, the bacteria in your mouth like eating it even more, using it to produce an acidic byproduct that慢慢吃牙釉质.
蛀牙是全球极为普遍的问题。根据2016年全球疾病负担研究出版于柳叶刀，大约有4.86亿儿童的牛奶牙齿（婴儿，小牙齿或落叶牙齿）腐烂，全世界约有24亿人在龋齿（牙齿腔）中生活。
在一个完美的世界中，搪瓷会像其他主要身体组织一样修复自己，例如平滑肌组织。不幸的是，由于搪瓷主要由无机矿物质组成，因此它并不自然再生，这使牙医用金属，陶瓷和玻璃陶瓷.
If researchers could create enamel in the laboratory, it would be an ideal way to repair teeth. It would adhere well to existing enamel (unlike牙科汞合金) and would match the existing enamel in hardness, thus avoiding unnaturally wearing down opposing teeth (as happens sometimes withceramic crowns）。
但是，创建搪瓷并不简单。“尽管通过使用各种策略，例如直接溶液矿化,蛋白质/肽诱导的矿化,水凝胶驱动的矿化， 和前体组件，由于无法在实验室中大规模复制自然牙釉质的复杂层次结构，因此无法实现临床开发的适用维修。纸.
研究人员来自夸江大学，郑安格大学医学院和中国的Xiamen大学，他们的论文于今年8月发表科学进步S提出了一种新的搪瓷策略，以建立先前的尝试。
“There is growing evidence that biomineralization at the growth frontier occurs in an integrated crystalline-amorphous interface,” they explain in the paper. “Inspired by these biological processes, we suggest that a rationally designed structure between HAP [hydroxyapatite, Ca10(PO4)6(OH)2] and amorphous calcium phosphate [ACP; Ca3(PO4)2·nH2O] may mimic the biomineralization frontier to induce epitaxial regeneration of enamel.”
In a先前的研究using small ACP particles (~20 nm), the researchers found the particles could adsorb and even assemble onto enamel HAP crystals, but they failed to induce epitaxial growth of enamel crystals. “In general, coalescence and fusion between particles occur more readily at smaller sizes,” the researchers write. “Accordingly, a question arises: What is the minimum size of the ACP particles that can be used in HAP growth studies?”
为了创建较小的ACP颗粒，研究人员测试了一种不同的合成方法，而不是反应Na2HPO4solution with CaCl2解决方案，他们使用磷酸钙离子簇（CPICS，〜1.5 nm）作为ACP的基本构建块。（为防止超质离子簇自发聚集，研究人员使用有机化合物三乙胺作为稳定剂。）
“In contrast to the other bulk ACP consolidated from nanoparticles, no particle, grain, or material boundaries could be observed within the CPIC-induced ACP by scanning electron microscopy (SEM) and atomic force microscopy (AFM), implying a structural continuity,” the researchers write in the paper. “This structural continuity can be extended to HAP-ACP interface to establish the mimetic biomineralization frontier.”
After their success inducing epitaxial regeneration with HAP (which serves as a simplified mineral model to investigate enamel formation and reconstruction), the researchers tried combining their CPIC-induced ACP with actual human enamel—with impressive results.
“In general, enamel rods run in a perpendicular direction to the enamel surface, and inter-rod enamel is at an angle of approximately 60° to the enamel rods … this unique feature of natural enamel could be precisely replicated within 48 hours by using the CPIC material,” the researchers write. “The boundary between the repaired and native enamel (protected by nail varnish during the repair) demonstrates successful epitaxial growth.”
虽然这早期的成功是有前途的,有年代till a few challenges to address before the method is viable for real-life use. In particular, the method repaired the enamel layer to about 2.5 μm of thickness; in application, it would need to be scaled up to 0.5–2 mm. Additionally, “there are a wide spectrum of dental cavities,”Shao Changyu该研究的主要作者在一所夸江大学说press release. “We need to develop our regenerative model for different circumstances so as to ensure controllability and effectiveness.”
该论文发表在科学进步， 是 ”通过仿生矿化边界修复牙釉质，确保外延生长” (DOI: 10.1126/sciadv.aaw9569).