Development of all-round diagnostic method for carious lesion activity using electrical and color methods

本研究的目的是利用颜色（CIE 1976L^*a^*b^*颜色系统）、电学和激光（DIAGNOdent）方法建立临床诊断龋齿病变活动性的客观方法。首先，探讨了这些方法诊断龋齿的适用条件。结果表明：1)电法适用于龋病内部的三维评价；2)评价配色标本对牙本质进行适当颜色校正的准确性并确定最合适的配色标本；3)牙本质的诊断值与L^*值呈较强的负相关。其次，在牙髓表面向牙髓腔方向的所有切片中，研究颜色、电、激光检测结果与Knoop硬度分布、细菌PCR检测结果之间的关系。具体而言，1)活动性龋齿的努氏硬度增加幅度大于迟滞性龋齿。活动性病变表面的a^*值大于静止病变表面的a^*值。因此，牙本质龋齿的a^*值适用于治疗前的龋齿活动度。2)电法适用于治疗前龋病进展程度的评价。3)龋病牙本质的L^*值和DIAGNOdent值适合评价龋病的情况，因为随着龋病切片的加深，L^*值增大，DIAGNOdent值减小。4)当活动性病变和静止性病变的L^*值均大于65时，细菌检出率为0%。第三，常规诊断方法对牙本质除龋后的颜色和激光评价结果不一。根据实验结果，可以评估治疗前牙本质龋的活动性、龋的进展程度、除龋过程中牙本质龋的情况以及牙本质龋的细菌检出率。少

The aim of this study was to establish the objective method for clinical diagnosis of carious lesion activity using color (CIE 1976L^*a^*b^* color system), electrical and laser (DIAGNOdent) methods. First, the suitable conditions of these methods for carious diagnosis were investigated. From the results, 1) the electrical method was suitable for three-dimensional evaluation for the inside of carious lesion, 2) the accuracy of the color-matching specimens for proper color correction of carious dentin were evaluated and the most suitable one was decided, 3) there was strong negative correlation in carious dentin between DIAGNOdent values and L^* values. Second, in all sections of carious lesion from the surface toward the pulp cavity, the relationships among the results of color, electrical and laser methods, the distribution of Knoop Hardness and bacterial evaluation using PCR were investigated. Concretely, 1) the increase rate of Knoop Hardness in the active carious lesions was larger … More than that in the arrested lesions. The a^* values of the surfaces of the active lesions were larger than those of arrested lesions. Therefore, the a^* values of carious dentin was suitable for the carious lesion activity before treatment. 2) The electrical method was suitable for evaluation of the degree of caries progress before treatment. 3) The L^* values and DIAGNOdent values of carious dentin were suitable for evaluation of carious condition in the lesions because the L^* values increased and the DIAGNOdent values decreased as the sections of lesions were deep. 4) When the L^* values were more than around 65 in both active and arrested lesions, the rates of bacterial detection were 0%. Third, the results of color and laser evaluations for carious dentin after caries removal using conventional diagnostic method were various. From the results of these experiments, the carious lesion activity and the degree of caries progress before treatment, the carious condition in the lesions during caries removal and the rates of bacterial detection of carious dentin can be evaluated using the color, electrical and laser methods. Less