Analysis of the hardness of a new restorative material for ART: Glass Carbomer

Abstract Objective This study evaluated the microhardness of two encapsulated ionomer materials – Glass Carbomer (GC-GCP Dental) and Riva Light Cure (RL-SDI) in combination with four light curing units (Carbo LED lamp, GCP-Dental, Demi LED curing light, Kerr, Poli Wireless, Kavo, Radii Plus, SDI). Material and method Eighty specimens were prepared following the manufacturer’s guidelines, 40 for each ionomer material and for 10 specimens, one light curing unit was used. After 7 days of storage in distilled water and at room temperature, 80 specimens were tested with the Vickers hardness (microhardness HMV 2T, Shimadzu, Japan). Five indentations were performed on each specimen (center, right, left, top and bottom). The test was carried out under a load of 100 g, with a 10 second penetration time. Result Independent of the curing unit the Riva Light Cure (RL-SDI) obtained the lower hardness than the material Glass Carbomer (GC-GCP-Dental). The microhardness of Glass Carbomer (GC-GCP-Dental) was influenced by the type of curing unit used as a heat treatment. The analysis of variance and Tukey test (p<0.05) showed that the interaction of factors material vs. curing unit (p<0.001), the main factor material (p<0.001) and curing unit (p=0.002) were statistically significant. Conclusion The ionomeric material Glass Carbomer (GCP-Dental) had significantly higher hardness value when compared with glass ionomer modified by resin Riva Light Cure (SDI), regardless of the light curing unit used.摘要 目的：本研究旨在评估两种封装型离聚物材料——玻璃卡波姆（Glass Carbomer，GC-GCP Dental）与光固化型瑞娃（Riva Light Cure，RL-SDI），分别搭配四款光固化单元的显微硬度，四款光固化单元具体为GCP-Dental品牌Carbo LED灯、Kerr品牌Demi LED固化灯、KaVo品牌Poli Wireless及SDI品牌Radii Plus。材料与方法：按照制造商操作规程制备80个试样，每种离聚物材料各40个，每款光固化单元对应10个试样。将所有试样置于室温蒸馏水中储存7天后，采用维氏硬度计（Vickers hardness，型号HMV 2T，岛津，日本）对80个试样进行显微硬度测试。每个试样分别于中心、右侧、左侧、顶部及底部位置施加5个压痕，测试载荷为100g，压痕保持时间为10秒。结果：无论搭配何种光固化单元，光固化型瑞娃（RL-SDI）的硬度均低于玻璃卡波姆（GC-GCP-Dental）。玻璃卡波姆（GC-GCP-Dental）的显微硬度受所采用的光固化热处理单元类型影响。方差分析（analysis of variance）与Tukey检验（显著性水平p<0.05）结果显示，材料与固化单元的交互效应（p<0.001）、两大主效应因子——材料因素（p<0.001）与固化单元因素（p=0.002）均具有统计学显著性。结论：无论使用何种光固化单元，树脂改性玻璃离聚物光固化型瑞娃（Riva Light Cure，SDI）的硬度均显著低于离聚物材料玻璃卡波姆（Glass Carbomer，GCP-Dental）。