Gong Victor, França Rodrigo
Dental Materials Research Lab, Department of Restorative Dentistry, College of Dentistry, University of Manitoba, 780 Bannatyne ave, Winnipeg, MB, R3E 0W2, Canada.
Dental Materials Research Lab, Department of Restorative Dentistry, College of Dentistry, University of Manitoba, 780 Bannatyne ave, Winnipeg, MB, R3E 0W2, Canada.
J Dent. 2017 Mar;58:11-18. doi: 10.1016/j.jdent.2016.12.009. Epub 2016 Dec 30.
The surface of any dental pulp-capping material has important implications for its clinical success because it is in direct contact with dental tissue, which influences its cytotoxicity. The aim was to determine the chemical composition of the first atomic layers of four pulp-protection agents because these atoms can initiate the pulp healing process.
Biodentine (Septodont), ProRoot MTA (Dentsply), Dycal (Caulk) and TheraCal (Bisco) were prepared (n=5) according to manufacturer recommendations. The chemical surface composition was analyzed using X-ray photoelectron spectroscopy (XPS), and the bulk composition was analyzed by Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX). Both survey and high resolution XPS spectra of the elements detected were obtained, with element-dependent probe depths of 4-5nm; the binding energy scale was normalized to the C1s adventitious carbon peak at 285eV.
There was a significant difference between bulk and surface compositions for all the pulp-capping materials. The calcium surface concentrations at 0nm and 70nm were Dycal 7.9% and 15.1%; ProRoot MTA 14.1% and 17%; TheraCal 0% and 3.6%; and Biodentine 17.6% and 33.7%, respectively. Trace amounts of the following elements (<1%) were also found: Ti, S and Zr in Biodentine; Bi in ProRoot MTA and TheraCal; Na, P, Zn and N in Dycal.
The XPS results showed that Ca in the surface layer could vary from 0 to 18%, depending on the material. Aliphatic carbons, from the polymerization reactions, especially in Dycal and TheraCal, were found to mask the other components.
This study compares, for the first time, the chemical composition of the first atomic layers of four pulp-capping materials. This information is relevant because the interaction between pulpar cells and the material's outermost atomic layer is an important factor for leading the pulpal response.
任何牙髓盖髓材料的表面对于其临床成功都具有重要意义，因为它与牙体组织直接接触，这会影响其细胞毒性。本研究旨在确定四种牙髓保护剂最外层原子层的化学成分，因为这些原子能够启动牙髓愈合过程。
按照制造商的建议制备生物活性牙本质（Septodont公司）、ProRoot MTA（登士柏公司）、Dycal（卡伯克公司）和TheraCal（必思可公司）（n = 5）。使用X射线光电子能谱（XPS）分析化学表面成分，通过傅里叶变换红外光谱（FTIR）、能量色散X射线光谱（EDX）分析整体成分。获得所检测元素的全扫描和高分辨率XPS光谱，元素相关的探测深度为4 - 5nm；结合能标度以285eV处的C1s非定形碳峰进行归一化。
所有盖髓材料的整体成分和表面成分之间存在显著差异。在0nm和70nm处钙的表面浓度分别为：Dycal为7.9%和15.1%；ProRoot MTA为14.1%和17%；TheraCal为0%和3.6%；生物活性牙本质为17.6%和33.7%。还发现了痕量的以下元素（<1%）：生物活性牙本质中的Ti、S和Zr；ProRoot MTA和TheraCal中的Bi；Dycal中的Na、P、Zn和N。
XPS结果表明，表层中的钙含量可在0%至18%之间变化，具体取决于材料。发现聚合反应产生的脂肪族碳，特别是在Dycal和TheraCal中，掩盖了其他成分。
本研究首次比较了四种牙髓盖髓材料最外层原子层的化学成分。该信息具有相关性，因为牙髓细胞与材料最外层原子层之间的相互作用是引导牙髓反应的重要因素。
