Araújo M G, Lindhe J
Department of Periodontology, Faculty of Odontology, Göteborg University, Sweden.
J Clin Periodontol. 1998 Jun;25(6):524-30. doi: 10.1111/j.1600-051x.1998.tb02482.x.
The aim of the present study was to evaluate the effect of enamel matrix proteins (EMD) on periodontal wound healing in degree III furcation defects in dogs. The experiment was performed in 5 foxhound dogs. 2 months prior to the start of the experiment, the 2nd and 4th lower premolars were extracted. Degree III furcation defects were created in the 3rd mandibular premolars (3P3). The furcation defects were subsequently exposed to reconstructive surgery. Buccal and lingual full thickness flaps were elevated in the lower premolar regions. The exposed root surfaces of the experimental teeth were planed. A notch was placed in the roots at the base of the defect. In one side of the mandible (Test group), phosphoric acid gel was applied over the root surfaces for 15 s. The acid was removed by flushing the root surfaces with sterile saline. Subsequently, a gel of EMD was applied to cover all instrumented root surfaces. Following gel application, a resorbable barrier membrane was adjusted to cover the buccal and lingual entrances of the furcation defect. The flaps were repositioned to cover the barrier and sutured. The contralateral premolar (Control group) received the same treatment, but acid etching was not performed and EMD was not applied prior to barrier installation. 4 months after reconstructive surgery, the animals were sacrificed and biopsies from the 3P3 regions harvested. The biopsies were placed in a fixative, demineralized in EDTA, dehydrated and embedded in paraffin. 3 mesiodistal sections, representing the central portion of the furcation site, were selected for histological analysis of the defect. The furcation defects of both the Test and Control groups were clinically closed and were found to harbor bone and periodontal ligament tissue which appeared to be in structural continuity with a newly formed root cementum. The relative amounts of mineralized bone, bone marrow and periodontal ligament tissue that had formed were similar in the Test and the Control group. In the Test group, however, the cementum that had formed in the apical portion of the furcation defect was different from the corresponding tissue in the coronal portion, and also different from the cementum observed in the Control group. In the apical portion of the test defect a thin (12 microm) acellular cementum had been laid down, while in the coronal portion a thick (32 microm) cellular cementum, similar to the cementum found in the Control group, could be observed. The current observation, hence, seems to confirm that EMD when applied onto an instrumented and acid etched dentine surface may create an environment conducive for the formation of acellular cementum.
本研究的目的是评估釉基质蛋白（EMD）对犬Ⅲ度根分叉病变牙周伤口愈合的影响。实验选用了5只猎狐犬。在实验开始前2个月，拔除第2和第4颗下颌前磨牙。在下颌第3前磨牙（3P3）制造Ⅲ度根分叉病变。随后对根分叉病变进行重建手术。在较低前磨牙区域掀起颊侧和舌侧全厚瓣。对实验牙齿暴露的根面进行平整。在病变底部的牙根处做一个切口。在一侧下颌骨（试验组），将磷酸凝胶涂覆在根面上15秒。通过用无菌盐水冲洗根面去除酸液。随后，应用EMD凝胶覆盖所有器械处理过的根面。凝胶应用后，调整可吸收屏障膜以覆盖根分叉病变的颊侧和舌侧入口。将瓣复位以覆盖屏障并缝合。对侧前磨牙（对照组）接受相同处理，但在安装屏障前不进行酸蚀且不应用EMD。重建手术后4个月，处死动物并采集3P3区域的活检组织。将活检组织置于固定剂中，在乙二胺四乙酸（EDTA）中脱矿，脱水并包埋在石蜡中。选取代表根分叉部位中央部分的3个近远中切片进行病变的组织学分析。试验组和对照组的根分叉病变在临床上均已闭合，并且发现含有骨组织和牙周韧带组织，这些组织似乎与新形成的牙根牙骨质在结构上连续。试验组和对照组形成的矿化骨、骨髓和牙周韧带组织的相对量相似。然而，在试验组中，根分叉病变顶部形成的牙骨质与冠部相应组织不同，也与对照组中观察到的牙骨质不同。在试验病变的顶部，已沉积了一层薄（12微米）的无细胞牙骨质，而在冠部，可以观察到一层厚（32微米）的细胞牙骨质，类似于对照组中发现的牙骨质。因此，目前的观察结果似乎证实，当将EMD应用于器械处理和酸蚀的牙本质表面时，可能会创造一个有利于无细胞牙骨质形成的环境。
