Büchter Andre, Joos Ulrich, Wiesmann Hans-Peter, Seper László, Meyer Ulrich
Department of Cranio-Maxillofacial Surgery, University of Münster, Münster, Germany.
Head Face Med. 2006 Feb 21;2:5. doi: 10.1186/1746-160X-2-5.
Initial stability of the implant is, in effect, one of the fundamental criteria for obtaining long-term osseointegration. Achieving implant stability depends on the implant-bone relation, the surgical technique and on the microscopic and macroscopic morphology of the implant used. A newly designed parabolic screw-type dental implant system was tested in vivo for early stages of interface reaction at the implant surface.
A total of 40 implants were placed into the cranial and caudal part of the tibia in eight male Göttinger minipigs. Resonance frequency measurements (RFM) were made on each implant at the time of fixture placement, 7 days and 28 days thereafter in all animals. Block biopsies were harvested 7 and 28 days (four animals each) following surgery. Biomechanical testing, removable torque tests (RTV), resonance frequency analysis; histological and histomorphometric analysis as well as ultrastructural investigations (scanning electron microscopy (SEM)) were performed.
Implant stability in respect to the measured RTV and RFM-levels were found to be high after 7 days of implants osseointegration and remained at this level during the experimented course. Additionally, RFM level demonstrated no alteration towards baseline levels during the osseointegration. No significant increase or decrease in the mean RFM (6029 Hz; 6256 Hz and 5885 Hz after 0-, 7- and 28 days) were observed. The removal torque values show after 7 and 28 days no significant difference. SEM analysis demonstrated a direct bone to implant contact over the whole implant surface. The bone-to-implant contact ratio increased from 35.8 +/- 7.2% to 46.3 +/- 17.7% over time (p = 0,146).
The results of this study indicate primary stability of implants which osseointegrated with an intimate bone contact over the whole length of the implant.
实际上，种植体的初期稳定性是实现长期骨整合的基本标准之一。实现种植体稳定性取决于种植体与骨的关系、手术技术以及所使用种植体的微观和宏观形态。一种新设计的抛物线形螺旋式牙种植体系统在体内进行了测试，以观察种植体表面界面反应的早期阶段。
在8只雄性哥廷根小型猪的胫骨颅侧和尾侧共植入40枚种植体。在所有动物中，于种植体植入时、此后7天和28天对每个种植体进行共振频率测量（RFM）。术后7天和28天（每组4只动物）采集块状活检样本。进行生物力学测试、可移除扭矩测试（RTV）、共振频率分析、组织学和组织形态计量分析以及超微结构研究（扫描电子显微镜（SEM））。
在种植体骨整合7天后，就所测量的RTV和RFM水平而言，种植体稳定性较高，并且在实验过程中保持在该水平。此外，在骨整合过程中，RFM水平未显示出向基线水平的变化。未观察到平均RFM（0天、7天和28天后分别为6029 Hz、6256 Hz和5885 Hz）有显著增加或减少。7天和28天后的移除扭矩值无显著差异。SEM分析表明在整个种植体表面存在骨与种植体的直接接触。随着时间推移，骨与种植体的接触率从35.8±7.2%增加到46.3±17.7%（p = 0.146）。
本研究结果表明，种植体在整个长度上与骨紧密接触实现骨整合，具有初期稳定性。
