Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Department of Prosthodontics, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
J Prosthodont. 2019 Feb;28(2):e661-e665. doi: 10.1111/jopr.12688. Epub 2017 Dec 14.
Improper seating of abutment on the implant is a common problem. This study investigated the effect of the type of implant/abutment interface on the complete seating of the abutments on the head of implants placed at different gingival depths.
Three implant systems with three different connections including straight external hexagon, butt-joint internal tri-lobed, and conical internal hexagon were used. Two gingival thicknesses (2 and 7 mm) were created using pink baseplate wax around the straight abutments seated on the implants. After placing the implants in acrylic blocks, the wax was replaced with the gingival mask material to simulate the gingival drape around the implant heads. Afterwards, 15 prosthodontists were asked to hand-tighten the straight abutments in the corresponding implant bodies relying only on their tactile sense. At the final stage, the gingival mask was removed, and the seating quality of the abutments on implant bodies was assessed visually. The effect of implant connection and depth on abutment seating accuracy was analyzed using Kruskal-Wallis and multiple-comparison tests.
No significant difference was found regarding the effect of either depth or connection design on the accuracy of the abutment seating (p > 0.05); however, pairwise comparison of the combined effect of the depth and connection design was significant (p = 0.009). Accuracy of abutment seating on the Nobel Active implants at both 2 and 7 mm depths were significantly better than Replace system with 7 mm depth (p = 0.027). The same results were obtained in comparison between Nobel Active system at both 2 and 7 mm depths with Branemark system with 7 mm depth (p = 0.006).
An increase in implant placement depth meant a decrease in accuracy of the abutment seating. The internal conical connection design showed the best result in abutment positioning in deep implants as compared with external and internal butt-joint connection designs.
基台在种植体上的不正确就位是一个常见的问题。本研究调查了种植体头部不同牙龈深度下，种植体/基台界面类型对基台完全就位的影响。
使用三种连接方式的三种种植体系统，包括直外六方、对接内三叶和锥形内六方。使用粉红色基底蜡在种植体上的直基台上创建两种牙龈厚度（2mm 和 7mm）。将种植体放入丙烯酸块中后，用牙龈成型材料代替蜡来模拟种植体头部周围的牙龈覆盖。之后，15 名修复医生仅依靠触觉手动将直基台拧紧到相应的种植体体中。在最后阶段，去除牙龈成型材料，目视评估基台在种植体体上的就位质量。使用 Kruskal-Wallis 和多重比较检验分析了种植体连接方式和深度对基台就位准确性的影响。
无论深度还是连接设计，对基台就位准确性都没有显著影响（p>0.05）；然而，深度和连接设计的综合效果的两两比较具有显著差异（p=0.009）。在 2mm 和 7mm 深度时，Nobel Active 种植体的基台就位准确性明显优于 7mm 深度的 Replace 系统（p=0.027）。在 2mm 和 7mm 深度的 Nobel Active 系统与 7mm 深度的 Branemark 系统之间的比较中也得到了相同的结果（p=0.006）。
种植体植入深度的增加意味着基台就位准确性的降低。与外六方和对接内三叶连接设计相比，内部锥形连接设计在深部种植体中基台定位方面的效果最好。
