采用传统和数字化方法制作的二硅酸锂瓷全冠的边缘适合性：三维分析。
Marginal Fit of Lithium Disilicate Crowns Fabricated Using Conventional and Digital Methodology: A Three-Dimensional Analysis.
机构信息
Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada.
Department of Oral Biological & Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada.
出版信息
J Prosthodont. 2018 Feb;27(2):145-152. doi: 10.1111/jopr.12656. Epub 2017 Aug 21.
PURPOSE
To compare the marginal fit of lithium disilicate (LD) crowns fabricated with digital impression and manufacturing (DD), digital impression and traditional pressed manufacturing (DP), and traditional impression and manufacturing (TP).
MATERIALS AND METHODS
Tooth #15 was prepared for all-ceramic crowns on an ivorine typodont. There were 45 LD crowns fabricated using three techniques: DD, DP, and TP. Microcomputed tomography (micro-CT) was used to assess the 2D and 3D marginal fit of crowns in all three groups. The 2D vertical marginal gap (MG) measurements were done at 20 systematically selected points/crown, while the 3D measurements represented the 3D volume of the gap measured circumferentially at the crown margin. Frequencies of different marginal discrepancies were also recorded, including overextension (OE), underextension (UE), and marginal chipping. Crowns with vertical MG > 120 μm at more than five points were considered unacceptable and were rejected. The results were analyzed by one-way ANOVA with Scheffe post hoc test (α = 0.05).
RESULTS
DD crowns demonstrated significantly smaller mean vertical MG (33.3 ± 19.99 μm) compared to DP (54.08 ± 32.34 μm) and TP (51.88 ± 35.34 μm) crowns. Similarly, MG volume was significantly lower in the DD group (3.32 ± 0.58 mm ) compared to TP group (4.16 ± 0.59 mm ). The mean MG volume for the DP group (3.55 ± 0.78 mm ) was not significantly different from the other groups. The occurrence of underextension error was higher in DP (6.25%) and TP (5.4%) than in DD (0.33%) group, while overextension was more frequent in DD (37.67%) than in TP (28.85%) and DP (18.75%) groups. Overall, 4 out of 45 crowns fabricated were deemed unacceptable based on the vertical MG measurements (three in TP group and one in DP group; all crowns in DD group were deemed acceptable).
CONCLUSION
The results suggested that digital impression and CAD/CAM technology is a suitable, better alternative to traditional impression and manufacturing.
目的
比较数字化印模和制造（DD）、数字化印模和传统压模制造（DP）以及传统印模和制造（TP）制作的二硅酸锂（LD）冠的边缘适合性。
材料和方法
在象牙仿头模型上对 15 号牙制备全瓷冠。使用三种技术制作 45 个 LD 冠：DD、DP 和 TP。使用微计算机断层扫描（micro-CT）评估三组中冠的 2D 和 3D 边缘适合性。在 20 个系统选择的点/冠处进行 2D 垂直边缘间隙（MG）测量，而 3D 测量则代表在冠边缘周向测量的 3D 间隙体积。还记录了不同边缘差异的频率，包括过度延伸（OE）、不足延伸（UE）和边缘崩裂。如果超过五个点的垂直 MG 大于 120μm，则认为冠不合格并被拒收。结果采用单因素方差分析和 Scheffe 事后检验（α=0.05）进行分析。
结果
DD 冠的平均垂直 MG（33.3±19.99μm）明显小于 DP（54.08±32.34μm）和 TP（51.88±35.34μm）冠。同样，DD 组的 MG 体积（3.32±0.58mm）明显低于 TP 组（4.16±0.59mm）。DP 组的 MG 体积平均值（3.55±0.78mm）与其他组无显著差异。在 DP（6.25%）和 TP（5.4%）组中，不足延伸误差的发生率高于 DD（0.33%）组，而在 DD（37.67%）组中，过度延伸的发生率高于 TP（28.85%）和 DP（18.75%）组。总体而言，根据垂直 MG 测量值，有 4 个制作的冠被认为不合格（TP 组 3 个，DP 组 1 个；DD 组的所有冠均被认为合格）。
结论
结果表明，数字化印模和 CAD/CAM 技术是一种合适的、更好的传统印模和制造替代方法。
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