Araújo M G, Berglundh T, Lindhe J
Department of Periodontology, Faculty of Odontology, Göteborg University, Sweden.
J Clin Periodontol. 1997 Oct;24(10):738-46. doi: 10.1111/j.1600-051x.1997.tb00191.x.
The aim of the experiment was to describe the formation of periodontal tissues in degree III furcation defects following GTR therapy. The study was performed in 8 foxhound dogs. The 2nd and 4th premolars in both sides of the mandible were extracted. Furcation defects were produced in the 3rd mandibular premolars. 3 weeks later, reconstructive surgery was performed. The dogs were scheduled for sacrifice 2, 4, 8, and 20 weeks after GTR therapy. Tissue blocks containing the experimental teeth were excised, demineralized in EDTA and embedded in paraffin. Serial sections were cut in the mesio-distal plane and parallel with the long axis of the roots. The microtome was set at 7 microns. The sections were stained in hematoxyline and eosin. From each biopsy, 3 sections representing the central part of the furcation, were selected for light microscopic examination. In the healed furcation sites, descriptive histological analysis of the newly-formed tissues was performed and the relative proportions of the hard and soft tissues were determined. It was demonstrated that at 2 weeks, the furcation defect contained granulation tissue and cell-rich connective tissue, while at 4 weeks the furcation was mainly occupied by connective tissue. At 8 weeks, woven bone occupied the central portion of the furcation, whereas connective tissue and cementum were observed in the lateral portions. The furcation area at 20 weeks was comprised of newly-formed cementum, periodontal ligament and bone. The onset of cementum formation had started as early as 2 weeks after GTR therapy. The cementum formation apparently occurred in 3 phases: organisation of collagen fibers adjacent and perpendicular to the root surface (phase 1), assembly of the collagen fibers and deposition of matrix (phase 2), and addition of cells and collagen fibers organised parallel to the root surface (phase 3). Bone formation took place through a process that included (1) organisation of a fibrous connective tissue, (2) differentiation of this tissue into woven bone and, (3) maturation of the woven bone into lamellar bone and bone marrow.
该实验的目的是描述引导组织再生（GTR）治疗后Ⅲ度根分叉病变中牙周组织的形成情况。研究在8只猎狐犬身上进行。拔除下颌两侧的第二和第四前磨牙。在下颌第三前磨牙制造根分叉病变。3周后，进行重建手术。在GTR治疗后2、4、8和20周安排处死这些犬。切除包含实验牙齿的组织块，在乙二胺四乙酸（EDTA）中脱矿并石蜡包埋。在近远中平面并与牙根长轴平行切取连续切片。切片厚度设定为7微米。切片用苏木精和伊红染色。从每次活检中，选择3个代表根分叉中央部分的切片进行光镜检查。在愈合的根分叉部位，对新形成的组织进行描述性组织学分析，并确定硬组织和软组织的相对比例。结果表明，在2周时，根分叉病变包含肉芽组织和富含细胞的结缔组织，而在4周时根分叉主要被结缔组织占据。在8周时，编织骨占据根分叉的中央部分，而在外侧部分观察到结缔组织和牙骨质。20周时的根分叉区域由新形成的牙骨质、牙周膜和骨组成。牙骨质形成早在GTR治疗后2周就已开始。牙骨质形成明显经历3个阶段：与牙根表面相邻并垂直的胶原纤维的排列（阶段1）、胶原纤维的组装和基质的沉积（阶段2），以及添加与牙根表面平行排列的细胞和胶原纤维（阶段3）。骨形成通过一个包括（1）纤维结缔组织的排列、（2）该组织分化为编织骨以及（3）编织骨成熟为板层骨和骨髓的过程发生。
