Department of Dentistry, Vita Salute University, San Raffaele Hospital, Milano, Italy.
Int J Oral Maxillofac Implants. 2009 Sep-Oct;24(5):920-6.
The aim of this clinical study was to assess the marginal bone around two different types of implant-abutment junctions-a so-called platform-switched assembly and a conventional external-hexagon connection-after 24 months.
Forty-five patients were included in this prospective study. All selected patients required the extraction of one or two hopeless teeth in maxillary and mandibular region monoradicular and second premolar teeth, and were randomly assigned to one of two groups. The first group received 34 implants with an external-hexagon junction with the abutment and the second group received 30 implants with platform-switched abutments. Implants were positioned immediately after tooth extraction and were loaded immediately.
After 24 months, a cumulative survival rate of 100% was reported for all implants. The platform-switching group showed a mean bone loss of 0.78 +/- 0.49 mm and the external-hexagon group showed a mean bone loss of 0.73 +/- 0.52 mm (no statistically significant difference between groups).
The results of this study indicate that implants placed immediately in fresh extraction sockets and loaded immediately represent a predictable procedure, with no differences in bone level changes between "platform-switched" and conventional external-hexagon implants after 24 months.
本临床研究旨在评估两种不同类型的种植体-基台连接体（一种所谓的平台转换连接体和一种传统的外六方连接体）在 24 个月后的边缘骨情况。
本前瞻性研究共纳入 45 例患者。所有入选患者均需要在上颌和下颌单根牙和第二前磨牙区域内拔除一颗或两颗无望牙齿，并随机分为两组。第一组接受 34 个带有外六方连接体和基台的种植体，第二组接受 30 个带有平台转换基台的种植体。拔牙后立即植入种植体并立即负载。
所有种植体的 24 个月累积存活率均为 100%。平台转换组的平均骨损失为 0.78±0.49mm，外六方组的平均骨损失为 0.73±0.52mm（两组间无统计学差异）。
本研究结果表明，在新鲜拔牙窝中即刻植入并即刻负载的种植体是一种可预测的方法，在 24 个月后，“平台转换”和传统外六方种植体之间的骨水平变化无差异。
