Lioubavina-Hack Natalia, Lang Niklaus P, Karring Thorkild
Department of Periodontology and Oral Gerontology, Royal Dental College, University of Aarhus, Aarhus, Denmark.
Clin Oral Implants Res. 2006 Jun;17(3):244-50. doi: 10.1111/j.1600-0501.2005.01201.x.
To investigate the significance of the initial stability of dental implants for the establishment of osseointegration in an experimental capsule model for bone augmentation.
Sixteen male rats were used in the study. In each rat, muscle-periosteal flaps were elevated on the lateral aspect of the mandibular ramus on both sides, resulting in exposure of the bone surface. Small perforations were then produced in the ramus. A rigid, hemispherical Teflon capsule with a diameter of 6 mm and a height of 4 mm and with a hole in its middle portion, prepared to fit the circumference of an ITI HC titanium implant of 2.8 mm in diameter, was fixed to the ramus using 4 mini-screws. On one side of the jaw, the implant was placed through the hole in such a way that its apex did not make contact with the mandibular ramus (test). This placement of the implant did not ensure primary stability. On the other side of the jaw, a similar implant was placed through the hole of the capsule in such a way that contact was made between the implant and the surface of the ramus (control). This provided primary stability of the implant. After placement of the implants, the soft tissues were repositioned over the capsules and sutured. After 1, 3, 6 and 9 months, four animals were sacrificed and subjected to histometric analysis.
The mean height of direct bone-to-implant contact of implants with primary stability was 38.8%, 52.9%, 64.6% and 81.3% of the implant length at 1, 3, 6 and 9 months, respectively. Of the bone adjacent to the implant surface, 28.1%, 28.9%, 52.6% and 69.6%, respectively, consisted of mineralized bone. At the test implants, no bone-to-implant contact was observed at any observation time or in any of these non-stabilized specimens.
The findings of the present study indicate that primary implant stability is a prerequisite for successful osseointegration, and that implant instability results in fibrous encapsulation, thus confirming previously made clinical observations.
在骨增量的实验性胶囊模型中，研究牙种植体初始稳定性对骨结合建立的意义。
本研究使用16只雄性大鼠。在每只大鼠双侧下颌支外侧掀起肌骨膜瓣，暴露骨面。然后在下颌支上制作小穿孔。准备一个直径6mm、高4mm、中间有孔的刚性半球形聚四氟乙烯胶囊，使其适合直径2.8mm的ITI HC钛种植体的周长，用4颗微型螺钉固定在下颌支上。在颌骨一侧，将种植体穿过孔放置，使其顶端不与下颌支接触（试验组）。这种种植体放置方式不能确保初始稳定性。在颌骨另一侧，将类似的种植体穿过胶囊孔放置，使种植体与下颌支表面接触（对照组）。这为种植体提供了初始稳定性。种植体放置后，将软组织重新放置在胶囊上并缝合。在1、3、6和9个月后，处死4只动物并进行组织计量学分析。
具有初始稳定性的种植体的直接骨-种植体接触平均高度在1、3、6和9个月时分别为种植体长度的38.8%、52.9%、64.6%和81.3%。与种植体表面相邻的骨中，分别有28.1%、28.9%、52.6%和69.6%为矿化骨。在试验组种植体中，在任何观察时间或任何这些不稳定标本中均未观察到骨-种植体接触。
本研究结果表明，种植体初始稳定性是成功骨结合的先决条件，种植体不稳定会导致纤维包裹，从而证实了先前的临床观察结果。
