Sidhom Marina, Zaghloul Hanaa, Mosleh Ihab El-Sayed, Eldwakhly Elzahraa
Fixed Prosthodontics Department, Faculty of Oral and Dental Medicine, Misr International University, Cairo 12677, Egypt.
Conservative Dentistry, Faculty of Oral & Dental Medicine, Misr International University, Cairo 12677, Egypt.
Polymers (Basel). 2022 Mar 22;14(7):1285. doi: 10.3390/polym14071285.
Minimal evidence exists on the efficacy of different digital manufacturing techniques in the fabrication of precise dental working models and provisional prosthesis. The objective was to evaluate the effect of two digital fabrication techniques (CAD/CAM milling and 3D printing) on the accuracy of PMMA working models and marginal fit of PMMA provisional prosthesis. Two abutment teeth of modified typodont were prepared. A reference stone model was fabricated, and an optical impression was performed to obtain a CAD reference model. Four CAM milled working models and four printed working models were fabricated. CAD software was used to design the provisional prostheses. Group A tested four milled provisional prosthesis, and group B tested four 3D printed prosthesis. The 3D accuracy of working models was assessed by superimposition of the control reference working model on the CAD test working model. A stereo-optical microscope was used to assess vertical marginal fit of the provisional dental prosthesis. Student's and Mann-Whitney U tests were utilized to compare the two groups. Results showed no statistically significant difference between the two tested groups. The two digital working model fabrication techniques recorded comparable accuracy. Similarly, 3D printed provisional prosthesis showed comparable marginal fit to the CAD/CAM milled ones.
关于不同数字制造技术在制作精确牙科工作模型和临时修复体方面的功效，现有证据极少。本研究的目的是评估两种数字制造技术（计算机辅助设计/计算机辅助制造（CAD/CAM）铣削和3D打印）对聚甲基丙烯酸甲酯（PMMA）工作模型的精度以及PMMA临时修复体边缘适合性的影响。对改良型牙模型的两颗基牙进行预备。制作一个参考石膏模型，并进行光学印模以获得CAD参考模型。制作了四个CAM铣削工作模型和四个打印工作模型。使用CAD软件设计临时修复体。A组测试四个铣削临时修复体，B组测试四个3D打印修复体。通过将对照参考工作模型与CAD测试工作模型叠加来评估工作模型的三维精度。使用立体光学显微镜评估临时牙修复体的垂直边缘适合性。采用学生t检验和曼-惠特尼U检验对两组进行比较。结果显示，两个测试组之间无统计学显著差异。两种数字工作模型制作技术的精度相当。同样，3D打印临时修复体的边缘适合性与CAD/CAM铣削的修复体相当。
