CAD/CAM制作瓷全冠边缘适合性的评价

Clinical evaluation on adaptation of ceramic crown made by CAD/CAM

目的 研究采用第二代计算机辅助设计及制作系统 (CERECⅡ )制作的瓷全冠的边缘适合性。方法在离体牙上制备标准的全瓷全冠预备体 ,采用CERECⅡCAD/CAM系统制作瓷全冠并就位 ,用工具显微镜测量瓷全冠与预备体之间的间隙。结果 所有全冠均能顺利就位 ,平均边缘间隙在肩台为 56± 2 6μm ,牙合面为 64± 2 1 μm ,轴面为 81± 3 1 μm ,其所有测量点的平均值为 64± 2 8μm。结论 CERECⅡ系统制作的标准瓷全冠就位顺利 ,边缘适合性达到临床应用要求。

Objective To evaluate the adaptation of the ceramic full-crowns made by the second-generation computer-assisted desing/computer-assisted manufacturing system (CAD/CAM)(CEREC 2,Sirona Dental Systems,Bensheim,Germany).Methods Extracted human molars free of surface defects and caries were prepared with standard crown preparations.Ceramic crown were fabricated with CEREC 2 CAD/CAM equipment and seated on preparations.For each restoration,gaps between the preparations and ceramic crowns were measured by travel microscope.Results No difficulty occurred in seating.Average marginal gaps for showder was 56±26 microns,for occlusal sites was 64±21 microns,and for interproximal sites was 81±31 microns.Average marginal gap for all sites combined was 64±28 microns.Conclusion The ability of the CEREC 2 to create ceramic crowns that seat without interference is remarkable.The adaptation of the ceramic crowns made by CEREC 2 is satisfactory to the clinical requirements.