Nondestructive Inspection of Resinous Restorations using an X-ray Micro focus CT Scanner

在牛牙本质（Φ4×2 mm）上制备了实验用的圆柱形空腔，并用复合树脂和树脂改性玻璃离聚体填充。一种光固化树脂复合材料（Clearfil APX, shade A2, Lot. 0664aa, Kuraray, Osaka）和一种树脂改性玻璃离子单体（富士II型离子单体LC， shade A2, Lot.）。选用粉末081132、液体271031 （GC, Tokyo）作为填充材料。它们被填入腔内，并按照制造商的建议进行处理。在填充复合材料之前，根据制造商的建议完成粘接工艺，即复合材料填充（Clearfil Mega Bond, Lot.011239,Kuraray, Osaka）和玻璃离子填充的调理（dental Conditioner Lot.261031，GC, Tokyo）的涂胶和粘接。每种材料制备3个标本。将标本浸泡在蒸馏水中，直到水被平衡吸收或在干燥器中与硅胶干燥2周。然后，使用x射线微聚焦CT扫描仪（MCT-CB100MF，日立医学，东京）对标本进行观察。在干燥条件下，修复体内部的气泡和裂缝等缺陷可以被显示出来，并且在腔壁和固定材料之间可以区分出大约15微米宽的间隙。x线微聚焦CT扫描对于修复体的质量控制和修复过程的改进是有用的，特别是对于树脂材料。

Experimental cylindrical cavities were prepared in bovine dentin(Φ4×2 mm) and filled with a composite resin and a resin modified glass ionomer. A light-cured resin composite (Clearfil APX, shade A2, Lot.0664AA, Kuraray, Osaka) and a resin modified glass ionomer (Fuji Ionomer Type II LC, shade A2, Lot. Powder 081132,liquid 271031,GC, Tokyo) were selected as filling materials. They were filled into the cavities and cured according to the manufacturer's recommendations. Before filling the composite, the bonding process, that is, the priming and bonding for the composite filling (Clearfil Mega Bond, Lot.011239,Kuraray, Osaka) and the conditioning (Dentin Conditioner Lot.261031,GC, Tokyo) for the glass ionomer filling were completed according to manufacturer's recommendations. Three specimens were prepared for each material. The specimens were immersed in distilled water until the water was absorbed in equilibrium or dried in a desiccator with silica gel over 2 weeks. Then, specimens were observed using an X-ray Microfocus CT Scanner (MCT-CB100MF, Hitachi Medico, Tokyo).In the dry condition defects inside the restorations such as air bubbles and cracks could be shown and gaps of about 15 microns in width between the cavity wall and the set material could be distinguished. The X-ray Microfocus CT Scanner appeared to be useful for the quality control of restorations and the improvement of the restorative process, especially for resinous materials.