Sahrmann P, Naenni N, Jung R E, Held U, Truninger T, Hämmerle C H F, Attin T, Schmidlin P R
Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
J Dent Res. 2016 Jun;95(6):623-8. doi: 10.1177/0022034516633432. Epub 2016 Feb 25.
The aim of the study was to test whether implants of 6 mm in length perform equally well as 10-mm implants in terms of survival and marginal bone-level changes when supporting single crowns. Patients with a posterior single-tooth gap were randomly allocated to either the placement of a 6-mm (test) or 10-mm implant (control). The treatment protocol allowed for internal sinus lift but not for lateral bone augmentation. After a healing period of 10 wk, implants were loaded with screw-retained single crowns. Survival rates, number of pockets ≥5 mm, and bleeding-on-probing were assessed clinically. The change of marginal bone level and crown-to-implant ratios were analyzed by 2 examiners. Longitudinal intragroup analyses for marginal bone levels were performed applying the Wilcoxon signed rank test. Intergroup differences at baseline and at 3 y were compared using the Mann-Whitney U test. The effect of implant length and crown-to-implant ratio on changes of marginal bone level also was determined. Of 94 implants placed (47 test and 47 control), 78 implants (40 test and 38 control) were available for follow-up examination at 3 y of loading. One test implant was lost during the second year. Hence, implant survival was not significantly different between the 2 groups after 3 y (98% test; 100% control). We found no significant change in the crestal bone level from baseline to 3 y for test and control implants with -0.19 ± 0.62 mm and -0.33 ± 0.71 mm, respectively. The intergroup difference was not significant. Crown-to-implant ratios were not associated with a statistically significant difference in marginal bone loss. However, the number of sites with pockets ≥5 mm was significantly higher in the test group. Based on the 3-y assessment, the use of 6-mm implants can be considered a viable option when reconstructing posterior single tooth gaps (German Clinical Trials Registry: DRKS00006290).
本研究的目的是测试在支持单冠时，6毫米长的种植体在存活率和边缘骨水平变化方面是否与10毫米种植体表现相当。有后牙单牙间隙的患者被随机分配接受6毫米种植体（试验组）或10毫米种植体（对照组）植入。治疗方案允许进行内提升但不允许进行侧方骨增量。经过10周的愈合期后，种植体上安装螺丝固位的单冠。临床评估存活率、深度≥5毫米的牙周袋数量和探诊出血情况。由两名检查者分析边缘骨水平的变化和冠-种植体比例。应用Wilcoxon符号秩检验对边缘骨水平进行纵向组内分析。使用Mann-Whitney U检验比较基线和3年时的组间差异。还确定了种植体长度和冠-种植体比例对边缘骨水平变化的影响。在植入的94颗种植体中（试验组47颗，对照组47颗），78颗种植体（试验组40颗，对照组38颗）在加载后3年可进行随访检查。一颗试验组种植体在第二年丢失。因此，3年后两组间种植体存活率无显著差异（试验组98%；对照组100%）。我们发现试验组和对照组种植体从基线到3年时嵴顶骨水平无显著变化，分别为-0.19±0.62毫米和-0.33±0.71毫米。组间差异不显著。冠-种植体比例与边缘骨丢失的统计学显著差异无关。然而，试验组中深度≥5毫米的牙周袋部位数量显著更高。基于3年的评估，在重建后牙单牙间隙时，使用6毫米种植体可被视为一种可行的选择（德国临床试验注册中心：DRKS00006290）。
