应用micro-CT检测复合树脂充填体微渗漏面积的研究

Detection of microleakage area of resin composites restorations in vitro by micro-CT

目的:应用显微CT(micro-CT)观测比较Ⅴ类洞4种复合树脂充填体的边缘微渗漏情况。方法:选取40颗人离体磨牙制备Ⅴ类洞,随机分为4组(n=10),分别用同一种粘接剂及4种光固化复合树脂充填修复:A组(3M Filtek Z350 XT通用型)、B组(Clearfil AP-X)、C组(Dentsply Spectrum TPH)、D组(3M Filtek P60)。再将试样浸入氨化硝酸银溶液12 h及显影液中8 h。经micro-CT扫描试样后,重建洞壁银(Ag)渗漏三维图像,测定充填体洞壁的整体银渗漏面积。采用单因素方差分析比较4种树脂充填体的微渗漏面积差异。结果:充填体微渗漏面积A组与B组差异无统计学意义(P>0.05);D组渗漏面积最大,显著大于其余3组(P<0.01);C组渗漏面积显著大于A组和B组(P<0.01)。结论:Micro-CT能建立银渗漏三维形态并精确测定窝洞渗漏面积;3M Filtek P60后牙充填体的微渗漏较其他三种通用型复合树脂充填体微渗漏严重。

Objective: To observe and compare the marginal microleakage of Class V restorations of 4 kinds of resin composites by using micro-CT. Methods: Class V cavity preparations were made in 40 extracted non-carious human molars, which were randomly divided into 4 groups( n= 10). They were restored with the same dental adhesive and 4 kinds of resin composites respectively,that group A(3M Filtek Z350 XT Universal Restorative),group B( Clearfil AP-X),group C( Dentsply Spectrum TPH)and group D(3M Filtek P60). Afterward,all teeth were then immersed in 50% ammoniacal silver nitrate solution for 12 hours,followed by a developing solution for 8 hours. At last, each tooth was scanned and the three-dimensional image of the silver leakage around cavity wall were reconstructed by micro-CT, and then the area of marginal silver leakage was measured. The single factor variance analysis was used to compare the leakage areas of four resin restorations. Results: There was no significant difference between group A and B(P>0. 05). Group D has the largest leakage area, and is significantly larger than the other three groups (P<0. 01),and group C leakage area was significantly larger than group A and B respectively ( P<0. 01). Conclusion: Micro-CT can display the three-dimensional shape of mircoleakage fully and detect the silver leakage area of restoration accurately. The microleakage of the 3M Filtek P60 restoration is more serious than that of the three universal resin composite restorations.