超瓷材嵌体边缘微漏的研究

Marginal microleakage in class Ⅱ-restorations after use of targis inlay

目的 研究超瓷材 (targis)嵌体边缘微漏情况。方法 将 10颗离体牙制备成两个邻牙合面的Ⅱ类洞 [近中邻牙合面洞 (MO)、远中邻牙合面洞 (DO) ],一侧颈壁位于釉牙骨质界上方 1mm(即颈壁位于牙釉质上 ) ,另一侧位于釉牙骨质界下方 1mm(即颈壁位于牙骨质上 ) ,均采用超瓷材嵌体修复 ,经 0～5 6℃冷热循环 2 0 0次后 ,用金刚砂片沿牙合面中部近远中方向将实验牙切成两半 ,在扫描电镜下观察微漏并拍照 ,扫描电镜图片经透扫仪输入电脑 ,在电脑屏幕上测量微漏情况。结果 超瓷材嵌体牙合壁均未见微漏现象 ;颈壁位于牙釉质处的超瓷材嵌体微漏发生率 (10 % )少于颈壁位于牙骨质处的超瓷材嵌体(30 % ) (P 0 .0 5 ) ;微漏程度与颈壁位置无关 (P 0 .0 5 ) ,颈壁位于牙釉质处的超瓷材嵌体的颈壁微漏平均值是 (0 .6 0± 0 .2 1) μm ,颈壁位于牙骨质处的超瓷材嵌体的颈壁微漏平均值是 (0 .6 7± 0 .19) μm。 结论 超瓷材嵌体具有较好的临床应用价值。

Objective To evaluate the marginal microleakage in class Ⅱ-restorations after use of targis inlay. Methods Ten extracted human molar teeth were prepared for MO(mesio-occlusal) and DO(disto-occlsa) cavities. In one type of cavity gingival margin was placed above the cemento-enamel junction (CEJ). In another type gingival margin was placed below the CEJ. Cavities were filled with targis inlays. All teeth were thermocycled 200 times between 0℃ and 56℃. Finally, all teeth were cut in mesial-distal direction with a band saw and the numbers of walls of cavities were determined under scanning electron microscope. Results There was no any microleakage in occlusal margin. The number of inlay microleakage of gingival margin placed below CEJ (30 %) was more than that of gingival margin placed above the CET (10 %) ( P <0.05). But there was no relationship of the microleakage degree between gingival margin placed below the CET and that placed above the CET. The average of the inlay microleakage of gingival margin placed above CEJ was (0.60±0.19)μm and that placed below CEJ was (0.67±0.19)μm. Conclusion Targis inlay has a practical value on class Ⅱ-restorations.