Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba–SP, Brazil.
Oper Dent. 2011 Mar-Apr;36(2):231-8. doi: 10.2341/10-107-L. Epub 2011 Jun 24.
The aim of the present study was to evaluate the influence of curing methods and composite volumes on the marginal and internal adaptation of composite restoratives. Two cavities with different volumes (Lower volume: 12.6 mm(3); Higher volume: 24.5 mm(3)) were prepared on the buccal surface of 60 bovine teeth and restored using Filtek Z250 in bulk filling. For each cavity, specimens were randomly assigned into three groups according to the curing method (n=10): 1) continuous light (CL: 27 seconds at 600 mW/cm(2)); 2) soft-start (SS: 10 seconds at 150 mW/cm(2)+24 seconds at 600 mW/cm(2)); and 3) pulse delay (PD: five seconds at 150 mW/cm(2)+three minutes with no light+25 seconds at 600 mW/cm(2)). The radiant exposure for all groups was 16 J/cm(2). Marginal adaptation was measured with the dye staining gap procedure, using Caries Detector. Outer margins were stained for five seconds and the gap percentage was determined using digital images on a computer measurement program (Image Tool). Then, specimens were sectioned in slices and stained for five seconds, and the internal gaps were measured using the same method. Data were submitted to two-way analysis of variance and Tukey test (p<0.05). Composite volume had a significant influence on superficial and internal gap formation, depending on the curing method. For CL groups, restorations with higher volume showed higher marginal gap incidence than did the lower volume restorations. Additionally, the effect of the curing method depended on the volume. Regarding marginal adaptation, SS resulted in a significant reduction of gap formation, when compared to CL, for higher volume restorations. For lower volume restorations, there was no difference among the curing methods. For internal adaptation, the modulated curing methods SS and PD promoted a significant reduction of gap formation, when compared to CL, only for the lower volume restoration. Therefore, in similar conditions of the cavity configuration, the higher the volume of composite, the greater the gap formation. In addition, modulated curing methods (SS and PD) can improve the interfacial quality of composite restorations through the reduction of internal gaps in lower volume composite restoratives.
本研究旨在评估固化方法和复合体积对复合修复体边缘和内部适应性的影响。在 60 颗牛牙的颊面制备了两个不同体积的腔（低体积：12.6mm(3)；高体积：24.5mm(3)），并用 Filtek Z250 进行整体填充。对于每个腔，根据固化方法将试件随机分为三组（n=10）：1）连续光（CL：600mW/cm(2) 下 27 秒）；2）软启动（SS：150mW/cm(2) 下 10 秒+600mW/cm(2) 下 24 秒）；和 3）脉冲延迟（PD：150mW/cm(2) 下 5 秒+无光照 3 分钟+600mW/cm(2) 下 25 秒）。所有组的辐射暴露量为 16J/cm(2)。用染色剂染色间隙程序测量边缘适应性，使用龋病检测仪。外边缘染色 5 秒，用计算机测量程序（Image Tool）上的数字图像确定间隙百分比。然后，将标本切成切片并染色 5 秒，用相同的方法测量内部间隙。数据采用双因素方差分析和 Tukey 检验（p<0.05）。复合体积对表层和内部间隙形成有显著影响，取决于固化方法。对于 CL 组，高体积修复体的边缘间隙发生率高于低体积修复体。此外，固化方法的效果取决于体积。关于边缘适应性，与 CL 相比，SS 组在高体积修复体中显著减少了间隙形成。对于低体积修复体，三种固化方法之间没有差异。对于内部适应性，调制固化方法 SS 和 PD 仅在低体积修复体中与 CL 相比，显著减少了间隙形成。因此，在腔配置相似的情况下，复合体积越高，间隙形成越大。此外，调制固化方法（SS 和 PD）可以通过减少低体积复合修复体的内部间隙来提高复合修复体的界面质量。
