早期功能负荷对游离自体骨移植维持及种植体骨整合的影响：犬实验研究

Faria Paulo E P, Carvalho Alexandre L, de Torres Erica M, Rasmusson Lars, Salata Luiz A

Department of Oral and Maxillofacial Surgery, University of the State of São Paulo, Faculty of Dentistry of Aracatuba, Aracatuba, Brazil.

J Oral Maxillofac Surg. 2010 Apr;68(4):825-32. doi: 10.1016/j.joms.2009.04.077.

PURPOSE

The aim of the present study was to investigate the healing, integration, and maintenance of autogenous onlay bone grafts and implant osseointegration either loaded in the early or the delayed stages.

MATERIALS AND METHODS

A total of 5 male dogs received bilateral blocks of onlay bone grafts harvested from the contralateral alveolar ridge of the mandible. On one side, the bone block was secured by 3 dental implants (3.5 mm x 13.0 mm, Osseospeed; AstraTech AB, Mölndal, Sweden). Two implants at the extremities of the graft were loaded 2 days after installation by abutment connection and prosthesis (simultaneous implant placement group); the implant in the middle remained unloaded and served as the control. On the other side, the block was fixed with 2 fixation screws inserted in the extremities of the graft. Four weeks later, the fixation screws were replaced with 3 dental implants. The loading procedure (delayed implant placement group) was performed 2 days later, as described for the simultaneous implant placement sites. The animals were sacrificed 12 weeks after the grafting procedure. Implant stability was measured through resonance frequency analysis. The bone volume and density were assessed on computed tomography. The bone to implant contact and bone area in a region of interest were evaluated on histologic slides.

RESULTS

The implant stability quotient showed statistical significance in favor of the delayed loaded grafts (P = .001). The bone-to-implant contact (P = .008) and bone area in a region of interest (P = 0.005) were significantly greater in the delayed group. Nevertheless, no difference was found in terms of graft volume and density between the early loaded and delayed-loaded approaches.

CONCLUSIONS

The protocol in which the implant and bone graft were given delayed loading allows for effective quality of implant osseointegration and stabilization, with healing and remodeling occurring in areas near the implant resulting in denser bone architecture.

目的

本研究旨在调查早期或延迟加载的自体覆盖骨移植的愈合、整合和维持情况以及种植体骨结合情况。

材料与方法

总共5只雄性犬接受了从下颌对侧牙槽嵴采集的双侧覆盖骨移植块。一侧，骨块由3颗牙种植体（3.5毫米×13.0毫米，Osseospeed；瑞典莫恩达尔的阿斯特拉泰克公司）固定。种植体安装后2天，通过基台连接和修复体对移植块两端的两颗种植体进行加载（同期种植体植入组）；中间的种植体不加载，作为对照。另一侧，通过在移植块两端插入2颗固定螺钉来固定骨块。4周后，将固定螺钉更换为3颗牙种植体。2天后进行加载程序（延迟种植体植入组），加载方式与同期种植体植入部位相同。移植手术后12周处死动物。通过共振频率分析测量种植体稳定性。通过计算机断层扫描评估骨体积和密度。在组织学切片上评估感兴趣区域的骨与种植体接触情况和骨面积。