Drexler P, García-Godoy F, Boj J R
Department of Pediatric Dentistry, University of Barcelona, Spain.
Pediatr Dent. 1997 Sep-Oct;19(6):419-20.
The purpose of this study was to evaluate the surface hardness of a resin composite (TPH) polymerized with and without the use of a transparent light-curing cone. Twenty composite blocks were made on a Teflon mold with cylindrical holes of 3 mm depth and 6 mm radius, and were light cured following different procedures. Group 1: Ten samples were pressed with a glass slide and light cured for two 40-sec exposures without the plastic cone; Group 2: Ten samples were light cured using the transparent plastic cone which was pressed down into the composite until the tip was 1 mm from the floor of the cylindrical Teflon mold. The curing light was activated for 40 sec. The cone was then removed and the remaining part of the mold was filled in one portion, pressed with a glass slide, and light cured for 40 sec. After curing, the samples were placed in distilled water for 48 hr. The hardness of the samples was then measured with a Rockwell Hardness Tester at three different points on each composite block; therefore, 30 measurements per group were taken. The data were statistically analyzed using an unpaired Student's t test. The results revealed that the resin composite cured with the transparent plastic cone had a statistically significant higher surface hardness value (P < 0.0001) than the group cured without the cone.
本研究的目的是评估在使用和不使用透明光固化头的情况下聚合的树脂复合材料（TPH）的表面硬度。在一个带有深度为3毫米、半径为6毫米圆柱形孔的聚四氟乙烯模具上制作了20个复合块，并按照不同程序进行光固化。第1组：10个样品用载玻片按压，在不使用塑料光固化头的情况下进行两次40秒的曝光光固化；第2组：10个样品使用透明塑料光固化头进行光固化，将光固化头向下压入复合材料中，直到尖端距离圆柱形聚四氟乙烯模具底部1毫米。固化光激活40秒。然后移开光固化头，将模具的其余部分一次性填满，用载玻片按压，并光固化40秒。固化后，将样品置于蒸馏水中48小时。然后用洛氏硬度计在每个复合块的三个不同点测量样品的硬度；因此，每组进行30次测量。使用非配对学生t检验对数据进行统计分析。结果显示，使用透明塑料光固化头固化的树脂复合材料的表面硬度值在统计学上显著高于未使用光固化头固化的组（P < 0.0001）。
