White J M, Goodis H E, Marshall S J, Marshall G W
UCSF School of Dentistry, Department of Restorative Dentistry 94143-0758.
J Dent Res. 1994 Sep;73(9):1560-7. doi: 10.1177/00220345940730091201.
Clinical simulations and restorative materials research and development conducted in vitro require the use of large numbers of extracted teeth. The simultaneous need for infection control procedures and minimal alterations of structure and properties of the tissue prompted this study of gamma irradiation as a method to eliminate microbes associated with extracted teeth and their storage solutions. Evaluations of potential change in structure of dentin were conducted in terms of permeability, Fourier transform infrared spectroscopy (FTIR), and optical properties. The dose required for sterilization by gamma irradiation was established by means of a tooth model inoculated with Bacillus subtilis (10(8) organisms/mL). Sterilization occurred at a dose above 173 krad with use of a Cesium (Cs137) radiation source. Gamma irradiation did not affect permeability of crown segments of dentin. A comparative evaluation of the effects of four sterilization methods on dentin disks was based on FTIR and ultraviolet-visible-near infrared (UV/VIS/NIR) spectra before and after sterilization by (1) gamma irradiation; (2) ethylene oxide; (3) dry heat; and (4) autoclaving. No detectable changes were found with gamma irradiation, but all other methods introduced some detectable change in the spectra. This suggests that common methods of sterilization alter the structure of the dentin, but gamma irradiation shows promise as a method which both is effective and introduces no detectable changes as measured by FTIR, UV/VIS/NIR, or permeability.
体外进行的临床模拟以及修复材料研发需要使用大量的拔除牙。由于同时需要进行感染控制程序，并且要尽量减少对组织结构和性能的改变，因此开展了本研究，以探讨γ射线辐照作为一种消除与拔除牙及其储存溶液相关微生物的方法。通过渗透性、傅里叶变换红外光谱（FTIR）和光学特性对牙本质结构的潜在变化进行了评估。通过接种枯草芽孢杆菌（10⁸ 个生物体/毫升）的牙齿模型确定了γ射线辐照灭菌所需的剂量。使用铯（Cs137）辐射源时，剂量高于173千拉德可实现灭菌。γ射线辐照未影响牙本质冠部的渗透性。基于FTIR以及灭菌前后的紫外-可见-近红外（UV/VIS/NIR）光谱，对四种灭菌方法对牙本质盘的影响进行了比较评估，这四种方法分别为：（1）γ射线辐照；（2）环氧乙烷；（3）干热；（4）高压灭菌。γ射线辐照未发现可检测到的变化，但所有其他方法均在光谱中引入了一些可检测到的变化。这表明，常用的灭菌方法会改变牙本质的结构，但γ射线辐照有望成为一种既有效又不会像通过FTIR、UV/VIS/NIR或渗透性测量那样引入可检测到变化的方法。
