Gen Dent. 2022 Nov-Dec;70(6):34-39.
The aim of this study was to compare the sizes of the implant-abutment microgap in Morse taper implants with a straight abutment (ISA group) and Morse taper implants with an angled abutment (IAA group). A total of 19 Morse taper dental implants (3.8 × 11.0 mm) were used with their respective abutments; 10 abutments were angled at 20°, and 9 were straight. The implant-abutment units were immersed in an epoxy resin to form a base and then cross-sectioned until about 50% of the volume was removed. The specimens were analyzed under a scanning electron microscope, and the size of the microgap was measured at 3 regions on each side of the implant, for a total of 6 measurements per specimen. Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis. In the ISA group, there were no statistically significant differences in the median sizes of the microgap at the different regions of the interface (P > 0.05; Kruskal-Wallis test). The mean (SD) values of the largest and smallest microgaps in the ISA group were 1.64 (1.38) and 0.83 (0.41) μm, respectively. In the IAA group, there was a statistically significant difference in the median sizes of the microgaps at the upper and middle regions on the left side (P = 0.031; Kruskal-Wallis test). The mean (SD) values of the largest and smallest micrograps were 1.43 (0.062) and 0.61 (0.27) μm, respectively. Comparison of the different regions in the ISA and IAA groups revealed that the only statistically significant difference was at the lower region on the right side (P = 0.027; Mann-Whitney U test). The sizes of the microgaps in the ISA and IAA groups were statistically similar in an overall analysis (P > 0.05; Mann-Whitney U test); however, the IAA group showed greater sealing ability. In addition, in both groups in vitro titanium oxide formation was observed at the interface, characterizing a type of cold-weld joint that provides effective implant-abutment sealing.
本研究旨在比较直基台（ISA 组）和斜基台（IAA 组）莫氏锥度种植体的种植体-基台微间隙大小。共使用 19 个莫氏锥度牙科种植体（3.8×11.0mm）及其相应的基台；其中 10 个基台倾斜 20°，9 个为直基台。将种植体-基台单元浸入环氧树脂中形成基底，然后进行切片，直到大约 50%的体积被切除。使用扫描电子显微镜对标本进行分析，在种植体的每侧 3 个区域测量微间隙的大小，每个标本共测量 6 次。采用 Mann-Whitney U 和 Kruskal-Wallis 检验进行统计学分析。在 ISA 组中，界面不同区域的微间隙中位数大小无统计学差异（P＞0.05；Kruskal-Wallis 检验）。ISA 组中最大和最小微间隙的平均值（SD）分别为 1.64（1.38）μm 和 0.83（0.41）μm。在 IAA 组中，左侧上、中区域微间隙中位数大小有统计学差异（P=0.031；Kruskal-Wallis 检验）。最大和最小微间隙的平均值（SD）分别为 1.43（0.062）μm 和 0.61（0.27）μm。对 ISA 和 IAA 组不同区域的比较显示，只有右侧下区域有统计学差异（P=0.027；Mann-Whitney U 检验）。在总体分析中，ISA 和 IAA 组的微间隙大小无统计学差异（P＞0.05；Mann-Whitney U 检验）；然而，IAA 组显示出更好的密封能力。此外，在两组体外均观察到界面处形成的氧化钛，表现为一种冷焊接头，提供了有效的种植体-基台密封。
