不同光固化方法对可压型及通用型树脂硬度的影响

Influence of two photoactivation modes on the hardness of packable and conventional resin-based composites

背景:弱光启动是近年来应用于临床的新的固化方法,其对复合树脂的性能具有一定的影响,以往国外的研究主要是针对通用型树脂进行的,而对可压型树脂的研究报道较少。目的:课题提出弱光启动固化对可压型复合树脂硬度产生影响的假设,并希望与通用型复合树脂进行比较加以验证。设计、时间及地点:双因素设计实验,于2007-10在中山大学附属第一医院口腔科和广东出入境检验检疫局检验检疫技术中心化矿金属材料实验室进行。材料:3种可压型复合树脂为:EcuShere-Carat(简称EC,德国DMG公司),FiltekP60(简称P60,美国3MEPSE公司),Tetric CeramHB(简称HB,列支敦士登Ivoclar Vivadent公司);通用型复合树脂为FiltekZ250(简称Z250,美国3MEPSE公司)。所有树脂颜色均为A3。方法:将3种可压型树脂及1种通用型树脂充填入直径7mm、高4mm的圆柱形容器中,每种树脂20个样本,分别以两种方法固化(每种10个样本)。弱光启动固化照射方法为300mW/cm2照射10s,600mW/cm2照射30s,常规光固化照射方法为600mW/cm2照射40s。主要观察指标:用维氏显微硬度计测量样本表面及底面的维氏显微硬度。结果:可压型复合树脂的硬度高于通用型复合树脂;弱光启动固化虽使3种可压型树脂表面硬度及底面硬度降低,但与常规光固化比较差别无显著性意义(P>0.05);弱光启动固化使通用型树脂表面及底面硬度均降低,两种固化方法差别有显著性意义(P<0.05)。结论:课题结论提示临床应根据不同的充填部位选择树脂种类以及光固化的具体方法。

BACKGROUND： Soft-start is a newly photoactivation mode, which has certain effect on composite resin. However, previous study mainly concentrated on the conventional resin-based composites, the reports regarding soft-start on packable resin-based composites is poorly understood. OBJECTIVE： It is assumed that soft-start photoactivation had effect on packable resin-based composites, in addition, to investigate its effect on the hardness of packable resin-based composites. DESIGN, TIME AND SETTING： A double factors design. The experiment was performed at the Department of Stomatology, First Affiliated Hospital, Sun Yat-sen University and Chemical Mine Metal Material Test Laboratory, Guangdong Inspection and Quarantine Technology Center in October 2007. MATERIALS： Three packable resin-based composites were Ecusphere-Carat （EC, DMG Company, Germany）, Filtek P60 （P60, 3M EPSE Company, USA）, Tetric Ceram HB （HB, Ivoclar Vivadent Company, Liechtenstein） and a conventional composite FiltekZ250 （Z250, 3M EPSE Company, USA）. The color of composites was A3. METHODS： Three packable resin-based composites and a conventional composite were filling in a cylindrical container （7 mm diameter, 4 mm depth）, to obtain 80 samples, and then were divided into different groups according to the composite and photoactivation mode （n=10）. In the soft-start photoactivation, samples were irradiated by 300 mW/cm^2 for 10 s, and then 600 mW/cm^2 for 30 s. Standard photoactivation was irradiated with 600 mW/cm^2 for 40 s. MAIN OUTCOME MEASURES： The microhardness of the top and bottom of the specimens was determined by Vickers microhardness tester. RESULTS： Three packable composites had higher hardness values than conventional composite. Though soft-start photoactivation could decrease the hardness of packable composites, the difference had no significant difference to standard mode （P 〉 0.05）. There was significant difference on the top hardness and on the bottom hardness of conventional composite between two photoactivation modes （P 〈 0.05）. CONCLUSION： The soft-start mode and resin-based composites should be selected carefully according to different filing areas.