AlRasheed Fellwa, AlWazzan Khalid
Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.
Saudi Dent J. 2022 May;34(4):288-297. doi: 10.1016/j.sdentj.2022.03.006. Epub 2022 Apr 2.
The purpose of this study was to compare the accuracy of fit of Co-Cr full arch screw-retained implant-supported fixed dental prosthesis fabricated among three different methods: conventional casting, milling, and additive manufacturing technology.
A master model of a completely edentulous mandible with five internal connection implants was utilized. Thirty full arch Co-Cr screw-retained implant-supported frameworks were fabricated by three different methods: conventional casting, milling, and additive manufacturing (AM) technology. The marginal fit was measured using a coordinate measuring machine in x-, y-, and z-axes, as well as the three-dimensional discrepancy. The casting group were measured twice: before the adaptation procedure and again after the adaptation procedure (sectioning and laser welding). For comparisons of marginal fit of frameworks between different groups one-way analysis of variance and Games Howell test was used. Paired -test was used to compare cast frameworks before and after adaption.
There were statistically significant differences in marginal fit and width distortion between groups ( <.05). The mean of total distortion of each group was 94.6 µm (SD 50.5 µm) for casting group before adaptation, 92.44 µm (SD 49.6 µm) for casting group after adaptation, 71.4 µm (SD 37.2 µm) for additive manufacturing group, while for the milling group the total distortion was 50.1 µm (SD 27.5 µm).
Full arch screw-retained implant-supported frameworks fabricated with any of the three fabrication techniques using cobalt-chromium material exhibited acceptable marginal fit. Milling fabrication technique showed the most accurate marginal fit. Adaptation procedure for the cast group has significantly improved the marginal fit.
本研究旨在比较三种不同方法制作的钴铬全牙弓螺丝固位种植体支持的固定义齿的适合度准确性：传统铸造法、铣削法和增材制造技术。
使用一个带有五个内连接种植体的无牙下颌主模型。通过三种不同方法制作30个钴铬螺丝固位种植体支持的全牙弓框架：传统铸造法、铣削法和增材制造（AM）技术。使用坐标测量机在x、y和z轴上测量边缘适合度以及三维差异。铸造组测量两次：在适配程序之前和适配程序之后（切片和激光焊接）。对于不同组之间框架边缘适合度的比较，使用单因素方差分析和Games Howell检验。配对t检验用于比较铸造框架适配前后的情况。
组间边缘适合度和宽度变形存在统计学显著差异（P<0.05）。铸造组适配前每组总变形的平均值为94.6µm（标准差50.5µm），适配后为92.44µm（标准差49.6µm），增材制造组为71.4µm（标准差37.2µm），而铣削组的总变形为50.1µm（标准差27.5µm）。
使用钴铬材料通过三种制造技术中的任何一种制作的全牙弓螺丝固位种植体支持的框架均表现出可接受的边缘适合度。铣削制造技术显示出最精确的边缘适合度。铸造组的适配程序显著改善了边缘适合度。
