Impedance spectroscopy of teeth with and without approximal caries lesions - An in vitro study
Impedance spectroscopy of teeth with and without approximal caries lesions - An in vitro study
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DOI：
10.1177/00220345960750110901
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发表时间：
1996-11-01
影响因子：
7.6
通讯作者：
Bruce, PG
中科院分区：
文献类型：
--
作者：
Huysmans, MCDNJM;Longbottom, C;Bruce, PG
在使用De或单次低频交流电流时，通过测量电阻来诊断龋病会受到极化效应的阻碍。电阻抗频谱技术可以在很大的频率范围内测量阻抗，它将提供有关牙齿电气特性的更详细信息。这项研究的目的是(A)表征整个拔除牙齿的复阻抗行为，在近表面测量，和(B)识别牙齿的复阻抗行为的参数，这将有助于区分龋病的程度。选择39颗拔除的前磨牙，59颗未修复和未受损(除龋齿外)的邻面。根据牙面形态分为三组：健康组(S组，n=16)、白斑或褐斑病变组(L组，n=33)和空洞组(C组，n=10)。这些牙齿被插入夹具中，夹具允许通过导电凝胶进行对电极接触。工作电极由碳化纤维材料组成。电阻抗测量的最大范围约为1 MHz至0.1赫兹。通过对等效电路的拟合，对阻抗数据进行分析。从数字和视觉两个方面对Fit进行评估。复阻抗谱自然地分为三组，与S、L和C的分类几乎完全一致。根据阻抗参数计算，这三组在去阻值(R(DC))上差别最大。S组、L组和C组的平均R(DC)分别为68M Omega、5.9MN和321k Omega。这些均值彼此之间有显著差异(对数变换数据，方差分析，p<；0.001；图基多重比较，p<；0.001)。结果表明，阻抗谱在区分健康、非空化龋病和空化的近牙面方面具有良好的体外性能。
Caries diagnosis by the measurement of electrical resistance is hampered by polarization effects when de or single-low-frequency ac currents are used. Electrical impedance spectroscopy, measuring impedance over a large range of frequencies, will provide more detailed information about the electrical characteristics of teeth. It was the aim of this study (a) to characterize the complex impedance behavior of whole extracted teeth, measured at the approximal surface, and (b) to identify parameters of the complex impedance behavior of the teeth which would be useful in distinguishing between degrees of carious involvement. Thirty-nine extracted premolar teeth with 59 unrestored and undamaged (excepting caries) approximal surfaces were selected. The tooth surfaces were divided into three groups according to their macroscopic appearance: sound (group S, n = 16), white- or brown-spot lesion present (group L, n = 33), or cavitated (group C, n = 10). The teeth were inserted into a jig which allowed for counter-electrode contact via a conducting gel. The working electrode consisted of a carbonated fiber material. Electrical impedance measurements were performed over a maximum range of about 1 MHz to 0.1 Hz. We analyzed electrical impedance data by fitting equivalent circuits. Fit was evaluated numerically and visually. The complex impedance spectra divided naturally into three groups which corresponded almost perfectly with the classifications of S, L, and C. The groups differed most in the de resistance (R(dc)), as calculated from the impedance parameters. Mean R(dc) for groups S, L, and C were 68 M Omega, 5.9 Mn, and 321 k Omega, respectively. These means were significantly different from each other (log-transformed data, ANOVA, p < 0.001; Tukey multiple comparisons, p < 0.001). It is concluded that the in vitro performance of electrical impedance spectroscopy in differentiating among sound, non-cavitated carious, and cavitated approximal tooth surfaces is excellent.