Grossman E S, Matejka J M
Dental Research Institute, University of the Witwatersrand, Johannesburg, South Africa.
J Prosthet Dent. 1995 Feb;73(2):199-209. doi: 10.1016/s0022-3913(05)80162-3.
Black's class I classic cavity preparations were completed in 124 extracted intact human premolars, of which 120 were restored with one of two silver amalgams, five different base combinations, and with or without cavity varnish. This resulted in 20 different restoration combinations. The other four teeth remained unrestored. Aging for 3 months and 1 year in 1% NaC1 at 20 degrees C followed. After aging, 80 of the restored teeth and the four unrestored teeth were subjected to an in vitro bacterial challenge for 36 days. The other 40 specimens were placed in an acidified (pH 4.0) broth for the same length of time. Sections were prepared for polarized light microscopy, and outer wall and dentin carious lesions were measured. The results were evaluated with one-way ANOVA and Tukey's Student range test with a critical level of statistical significance of p < 0.05 and p < 0.005. Lesions produced by bacterial challenge were significantly smaller than those formed by acidified broth. Aging time and varnish did not significantly influence lesion size. Low copper amalgam, a calcium hydroxide paste base, and restoration per se significantly reduced lesion size. Reproducible measurement of wall lesion length was not possible. Secondary caries lesion size can be minimized by judicious selection of restoration material combinations.
在124颗完整拔除的人类前磨牙上完成了布莱克I类经典洞形预备，其中120颗用两种银汞合金之一、五种不同的基底组合进行修复，且有的使用了洞漆，有的未使用。这产生了20种不同的修复组合。另外四颗牙齿未做修复。随后在20摄氏度的1%氯化钠溶液中分别老化3个月和1年。老化后，对80颗修复后的牙齿和四颗未修复的牙齿进行了36天的体外细菌攻击。另外40个样本在相同时间内置于酸化（pH 4.0）肉汤中。制备切片用于偏光显微镜观察，并测量外壁和牙本质龋损。结果采用单向方差分析和图基氏学生化极差检验进行评估，统计学显著性临界水平为p < 0.05和p < 0.005。细菌攻击产生的龋损明显小于酸化肉汤形成的龋损。老化时间和洞漆对龋损大小无显著影响。低铜汞合金、氢氧化钙糊剂基底以及修复本身显著减小了龋损大小。无法对洞壁龋损长度进行可重复测量。通过明智地选择修复材料组合可将继发龋损大小降至最低。
