Department Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Dent Mater. 2011 Apr;27(4):356-63. doi: 10.1016/j.dental.2010.11.015. Epub 2010 Dec 16.
This study sought to evaluate and compare the marginal and internal fit in vitro of three-unit FDPs in Co-Cr made using four fabrication techniques, and to conclude in which area the largest misfit is present.
An epoxy resin master model was produced. The impression was first made with silicone, and master and working models were then produced. A total of 32 three-unit Co-Cr FDPs were fabricated with four different production techniques: conventional lost-wax method (LW), milled wax with lost-wax method (MW), milled Co-Cr (MC), and direct laser metal sintering (DLMS). Each of the four groups consisted of eight FDPs (test groups). The FDPs were cemented on their cast and standardised-sectioned. The cement film thickness of the marginal and internal gaps was measured in a stereomicroscope, digital photos were taken at 12× magnification and then analyzed using measurement software. Statistical analyses were performed with one-way ANOVA and Tukey's test.
Best fit based on the means (SDs) in μm for all measurement points was in the DLMS group 84 (60) followed by MW 117 (89), LW 133 (89) and MC 166 (135). Significant differences were present between MC and DLMS (p<0.05). The regression analyses presented differences within the parameters: production technique, tooth size, position and measurement point (p < 0.05).
Best fit was found in the DLMS group followed by MW, LW and MC. In all four groups, best fit in both abutments was along the axial walls and in the deepest part of the chamfer preparation. The greatest misfit was present occlusally in all specimens.
本研究旨在评估和比较使用四种制作技术制作的 Co-Cr 三单位 FDP 的边缘和内部适合度，并确定最大不匹配出现在哪个区域。
制作了一个环氧树脂模型。首先用硅橡胶进行印模，然后制作主模型和工作模型。总共使用四种不同的生产技术制作了 32 个三单位 Co-Cr FDP：传统失蜡法（LW）、失蜡法铣削蜡（MW）、铣削 Co-Cr（MC）和直接激光金属烧结（DLMS）。每组包括 8 个 FDP（实验组）。将 FDP 粘接到其铸造体上，并进行标准化截面。在立体显微镜下测量边缘和内部间隙的粘结剂膜厚度，在 12×放大倍数下拍摄数字照片，然后使用测量软件进行分析。使用单因素方差分析和 Tukey 检验进行统计分析。
基于所有测量点的平均值（SD），所有测量点的最佳拟合度为 DLMS 组 84（60），其次是 MW 组 117（89）、LW 组 133（89）和 MC 组 166（135）。MC 组和 DLMS 组之间存在显著差异（p<0.05）。回归分析显示了参数内的差异：生产技术、牙齿大小、位置和测量点（p<0.05）。
最佳拟合度出现在 DLMS 组，其次是 MW 组、LW 组和 MC 组。在所有四个组中，在两个基牙中，最佳拟合度都在轴向壁上和倒角制备的最深部分。在所有样本中，最大不匹配出现在牙合面。
