引导性骨再生模型（GBR）成骨特点及骨髓的作用

目的∶研究引导性骨再生模型（ＧＢＲ）的成骨特点及骨髓的作用。材料与方法∶本实验应用了２４只新西兰兔，兔右侧桡骨为ＧＢＲ侧，左侧为去骨髓侧。ＧＢＲ侧手术过程：于兔右侧桡骨做１０ｍｍ骨缺损，以硅胶管套于缺损两侧；去骨髓侧以骨水泥封堵缺损两端髓腔。动物于３日、１、２、３、４、６、１０、１２周处死，标本做非脱钙骨切片，分析大体观察、Ｘ线及非脱钙骨组织切片结果。结果：（１）骨髓在ＧＢＲ模型膜管内成骨过程中起决定作用；（２）ＧＢＲ模型骨修复方式：于膜管内骨缺损两端分别形成两成骨尖端，两成骨尖端相对生长至愈合；（３）膜管内成骨过程早期为成骨细胞直接成骨过程，后期成骨尖端缺乏成熟皮质骨结构。结论：ＧＢＲ模型基础为隔膜干扰技术，其骨缺损修复为一特殊成骨过程，骨髓对其起决定作用。

Study of Characteristic of Bone Formation in Guided Bone Regeneration (GBR) and the Role of Bone Marrow in GBR

Objective:The characteristics of bone formation process in Guided Bone Regeneration (GBR) and the role of bone marrow in GBR was analyzed by means of undecalcified section and X- ray films. Methods: 10 mm long segmental defects were created in the diaphyses of both radii in 24 New Zealand rabbits. In the right side, the defect was covered with a tubular silicone membrane. In the left side,additionally, marrow cavities of both sides of the radius were blocked by cement. The animals were killed at the third day, the 1st, 2nd, 3rd,4th, 6th, 10th, 12th week. Samples were treated for radiological and histological studies. Results: (1) Bone marrow plays a critical role in GBR; (2) The healing process in GBR: The two bone formation ends showed healing in the GBR group, bone is formed inside membrane and they gradually develop to the center of the defect; (3) Bone formation involves direct differentiation of mesenchymal cells in the marrow into osteoblasts in early bone healing processand normal bone structure is not seen when the two ends of bone formation meet. Conclusion: GBR model is based on the membrane technique. Bone formation process in GBR is different from other bone healing process and bone marrow plays a critic role in GBR.