Grossman E S, Matejka J M
Dental Research Institute, Medical Research Council/University of Witwatersrand, Johannesburg, South Africa.
J Oral Rehabil. 1997 Jul;24(7):496-505. doi: 10.1046/j.1365-2842.1997.00529.x.
Black's class I classic cavities were cut in 120 sound extracted human premolars and restored with one of two silver amalgams, six different base combinations, with or without cavity varnish and then aged for 3 months or 1 year. Thereafter, the restored teeth were subjected to a bacterial or acid broth in vitro carious challenge for 36 days. Resin cast impressions were made of the restoration margin of each specimen before and after the carious challenge giving a total of 240 replicas. The replicas were examined in a scanning electron microscope (SEM) and the margins subjected to seven marginal assessment procedures: (i) ranking using micrographs of the margin; (ii) percentage length of marginal discrepancy; (iii) Mjor assessment using six groups; (iv) number of margin segments showing a discrepancy; (v) greatest gap size; (vi) ranking based firstly on gap size and then number of margin segments showing a discrepancy; and (vii) ranking based firstly on gap size and then percentage length of marginal discrepancy. The data from procedures (i), (ii), (vi) and (vii) were examined using one-way ANOVA; a linear logistic statistical analysis examined data from procedures (iii)-(v). Statistical significance was chosen at P < 0.05. It was found that procedure (vii) was able to discriminate between variables to a greater degree than all other procedures. It is recommended that a ranking system based on greatest gap size and percentage length of marginal discrepancy be used to assess marginal quality of amalgam restorations.
在120颗完好的拔除人类前磨牙上制备布莱克I类典型洞型，并用两种银汞合金之一、六种不同的基底组合进行修复，有或没有窝洞封闭剂，然后分别老化3个月或1年。此后，对修复后的牙齿进行36天的体外细菌或酸性肉汤致龋挑战。在致龋挑战前后，对每个样本的修复边缘制作树脂铸型印模，共得到240个复制品。在扫描电子显微镜（SEM）下检查这些复制品，并对边缘进行七种边缘评估程序：（i）使用边缘显微照片进行排序；（ii）边缘差异长度百分比；（iii）使用六组进行Mjor评估；（iv）显示差异的边缘段数量；（v）最大间隙尺寸；（vi）首先根据间隙尺寸排序，然后根据显示差异的边缘段数量排序；（vii）首先根据间隙尺寸排序，然后根据边缘差异长度百分比排序。使用单向方差分析检查程序（i）、（ii）、（vi）和（vii）的数据；使用线性逻辑统计分析检查程序（iii） - （v）的数据。选择P < 0.05作为统计学显著性水平。结果发现，程序（vii）比所有其他程序更能区分变量。建议使用基于最大间隙尺寸和边缘差异长度百分比的排序系统来评估银汞合金修复体的边缘质量。
