Welander Maria, Abrahamsson Ingemar, Berglundh Tord
Department of Periodontology, The Sahlgrenska Academy at Göthenburg University, Göthenburg 405 30, Sweden.
Clin Oral Implants Res. 2009 Mar;20(3):226-31. doi: 10.1111/j.1600-0501.2008.01637.x.
The aim of the present experiment was to study the healing around two-part implants that were placed in a subcrestal position.
Five mongrel dogs, about 2 years old, were included. The mandibular premolars and the first, second and third maxillary premolars were extracted. Three months later two test and two control implants (OsseoSpeed, 3.5 mm x 8 mm) were placed in one side of the mandible. The implants were placed in such a way that the implant margin was located 2 mm apical to the bone crest. In the test implants, the surface modification extended to the implant margin and, thus, included the shoulder part of the implant. Regular abutments with a turned surface (Zebra) were connected to the control implants, while experimental abutments with a modified surface (TiOblast) were connected to the test implants. A plaque control program that included cleaning of implants and teeth every second day was initiated. Four months later the dogs were euthanized and biopsies were obtained and prepared for histological analysis.
The marginal bone level at the test implants was identified in a more coronal position than that at the control implants. In 40% of the test implants, the bone-to-implant contact extended coronal of the abutment/fixture (A/F) border, i.e. in contact with the abutment part of the implant. The connective tissue portion of the peri-implant mucosa that was facing the test abutments contained a higher density of collagen and a smaller proportion of fibroblasts than that at the control sites.
It is suggested that osseointegration may occur coronal to the A/F interface of two-part implants. Such a result, however, appears to depend on the surface characteristics of the implant components.
本实验的目的是研究置于牙槽嵴顶下方位置的两段式种植体周围的愈合情况。
纳入5只约2岁的杂种犬。拔除下颌前磨牙以及上颌第一、第二和第三前磨牙。3个月后，在下颌一侧植入两枚测试种植体和两枚对照种植体（OsseoSpeed，3.5毫米×8毫米）。种植体的植入方式为使种植体边缘位于牙槽嵴顶根尖方2毫米处。在测试种植体中，表面改性延伸至种植体边缘，因此包括种植体的肩部部分。将具有车削表面的常规基台（Zebra）连接到对照种植体，而将具有改性表面的实验性基台（TiOblast）连接到测试种植体。启动了一个菌斑控制程序，包括每隔一天清洁种植体和牙齿。4个月后对犬实施安乐死并获取活检组织，准备进行组织学分析。
测试种植体处的边缘骨水平比对照种植体处的更靠近冠方。在40%的测试种植体中，骨与种植体的接触延伸至基台/种植体（A/F）边界的冠方，即与种植体的基台部分接触。与测试基台相对的种植体周围黏膜的结缔组织部分比对照部位含有更高密度的胶原和更小比例的成纤维细胞。
提示两段式种植体的骨结合可能发生在A/F界面的冠方。然而，这样的结果似乎取决于种植体部件的表面特性。
