Rasmusson L, Meredith N, Kahnberg K E, Sennerby L
Department of Biomaterials/Handicap Research, Göteborg University, Sweden.
Clin Oral Implants Res. 1999 Aug;10(4):267-77. doi: 10.1034/j.1600-0501.1999.100403.x.
The objective of the present report was to study the effects of barrier membranes on bone resorption and implant stability in a rabbit onlay bone graft model, using resonance frequency analysis, coordinate measurements on plaster models, removal torque measurements and histology. Disc-shaped bone grafts were harvested from the calvarium and placed with titanium implants in the proximal tibial metaphyses of 9 rabbits. On one side (test) the bone graft/implant was covered by an e-PTFE barrier, while the contralateral side was not covered by a membrane and served as control. Three animals were sacrificed after 8 weeks for histology. In 6 animals the membranes were removed after 8 weeks and the animals were followed for an additional period of 16 weeks. Implant stability and bone height around the implants was assessed for the test and control sides at Day 0 and 8, 16 and 24 weeks postoperatively. Removal torque tests were performed after 24 weeks. The results showed an increase in volume of the bone graft on the test side as long as the barrier membrane was in place. However, after removal of the membrane at 8 weeks the resorption rate was higher on the test side compared to the control side, resulting in a similar bone height after 24 weeks. There were no statistically significant differences in implant stability between the test and control sides at any time point, as measured with resonance frequency analysis. Additionally, no statistically significant differences were found between the test and control sides after 24 weeks, using removal torque measurements, coordinate measurements and histomorphometric evaluation. Thus, in this experimental model, the use of non-resorbable barrier membranes did not improve the stability of implants simultaneously placed with onlay bone grafts. Moreover, extensive resorption of the grafted bone was seen after barrier removal, which resulted in similar bone graft volume for the test and control sides at the end of the observation period.
本报告的目的是在兔覆盖性骨移植模型中，使用共振频率分析、石膏模型坐标测量、去除扭矩测量和组织学方法，研究屏障膜对骨吸收和种植体稳定性的影响。从兔颅骨获取盘状骨移植块，并将钛种植体植入9只兔胫骨近端干骺端。在一侧（试验侧），骨移植块/种植体用e-PTFE屏障膜覆盖，而对侧不覆盖膜作为对照。8周后处死3只动物进行组织学检查。6只动物在8周后取出屏障膜，并再随访16周。在术后第0天、8周、16周和24周评估试验侧和对照侧种植体的稳定性以及种植体周围的骨高度。24周后进行去除扭矩试验。结果显示，只要屏障膜在位，试验侧骨移植块的体积就会增加。然而，在8周时取出屏障膜后，试验侧的吸收速率高于对照侧，导致24周后骨高度相似。通过共振频率分析测量，试验侧和对照侧在任何时间点的种植体稳定性均无统计学显著差异。此外，使用去除扭矩测量、坐标测量和组织形态计量学评估，试验侧和对照侧在24周后也未发现统计学显著差异。因此，在该实验模型中，使用不可吸收的屏障膜并不能同时提高与覆盖性骨移植同时植入的种植体的稳定性。此外，取出屏障膜后可见移植骨大量吸收，导致观察期末试验侧和对照侧的骨移植块体积相似。
