计算机辅助设计与辅助制作纳米复合物陶瓷嵌体边缘微渗漏的研究

Comparative study of marginal microleakage of the computer aided design and computer aided manufacture inlays utilizing resin nano-ceramic blocks

目的:对比计算机辅助设计与辅助制作(computer aided design and computer aided manufacture,CAD/CAM)铸瓷嵌体和纳米复合物陶瓷嵌体边缘微渗漏的差异,为临床嵌体材料的选择提供依据。方法:选取30颗离体磨牙,随机分为A、B组,每组15颗。两组离体牙制备邻牙合面Ⅱ类洞,用CEREC AC系统切削和制作完成CAD/CAM嵌体,其中A组用IPS. e. max CAD瓷块,B组用Lava Ultimate优韧瓷块,所有试件均用RelyX Unicem树脂水门汀粘接。经冷热循环后,每组选取10颗,用流动树脂封闭牙齿根尖孔,亚甲基兰溶液染色后,从颊舌方向平行于牙体长轴纵向剖开,体视显微镜观测两组嵌体边缘微渗漏情况。剩余样本用扫描电镜观察粘接面形态特点。结果:两组嵌体的龈壁均出现微渗漏,铸瓷嵌体组龈壁微渗漏程度大于优韧瓷嵌体(t=1. 874,P=0. 0360<0. 05)。对于同一试件,龈壁微渗漏大于轴壁,差异有统计学意义。扫描电镜可见,优韧瓷嵌体组呈现更好的粘接界面。结论:优韧瓷嵌体龈壁的微渗漏小于铸瓷嵌体,从微渗漏方面评价,优韧瓷是制作嵌体材料的良好选择。

Objective:To evaluate the marginal microleakage of the computer aided design and computer aided manufacture inlays utilizing porcelain and resin nano-ceramic blocks.Methods:Thirty extracted molars were selected and randomly divided into two groups(15 teeth in each group),and classⅡcavities were made.The prepared teeth were restored with standardized CAD/CAM inlays using porcelain blocks(IPS.e.max)for groupA,and nano-ceramic blocks(Lava Ultimate)for groupB.All specimens were thermocycled.10 teeth in each group were stained for 24 h with methylene blue and cut twice in buccal-lingual direction.The degree of dye penetration was observed under stereomicroscope for the microleakage.The remaining specimens in each group were examining the surface of the adhesive interface with scanning electron microscope(SEM).Results:The present study revealed that groupA exhibited more microleakage(t=1.874,P=0.0360<0.05)at the gingival margin than groupB.The microleakage was more at the gingival margin when compared with occlusal margin on intergroup comparison and this was found to be statistically significant.GroupB had the better surface of the adhesive interface under the SEM.Conclusion:Nano-ceramic inlays showed significantly lower microleakage than porcelain inlay at the gingival margins.