Department of Implantology, Fondazione Policlinico Ca' Granda, University of Milan, Milan, Italy.
Clin Oral Implants Res. 2012 Jan;23(1):90-4. doi: 10.1111/j.1600-0501.2011.02196.x. Epub 2011 Apr 15.
To validate the "platform switching" concept at oral implants with respect to the preservation of the alveolar crestal bone levels in an animal model.
MATERIAL & METHODS: Five minipigs received three implants each with a 0.25 mm implant/abutment mismatch and were placed flush (T(0)), 1 mm below (T(1)) and 1 mm above (T(+1)) the alveolar bony crest, and as a control, one conventionally restored implant placed at the bone level. The implants were randomly inserted flapless into the mandible. Four months after implant insertion, the animals were sacrificed, and undecalcified block sections were obtained and used for histological analyses.
The mean values for peri-implant bone resorption were 1.09 ± 0.59 mm (Control), 0.51 (± 0.27 mm, T(0)), 0.50 (± 0.46 mm, T(+1)) and 1.30 (± 0.21 mm, T(-1)), respectively. Statistically significant differences (P<0.05) were found among the test (T(0), T(-1)) and the control sites. Control implants presented an average biologic width length of 3.20 mm (± 0.33), with a connective tissue adaptation compartment of 1.29 mm (± 0.53) and an epithelial attachment of 1.91 mm (± 0.71). T(0), T(+1) and T(-1) implants presented with a mean biologic width of 1.97 mm (± 1.20), 2.70 mm (± 1.36) and 2.84 mm (± 0.90), respectively, with a connective tissue adaptation compartment of 1.21 mm (± 0.97), 1.21 mm (± 0.65) and 1.50 mm (± 0.70) and an epithelial attachment of 0.84 mm (± 0.93), 1.66 mm (± 0.88) and 1.35 mm (± 0.44), respectively. Differences between the configurations were mainly associated with the length of the epithelial attachment. The epithelial attachment was significantly longer in the C sites than in T(0) (P=0.014). However, no other differences between configurations were detected.
If the implants are positioned at the level of the alveolar bony crest, the platform-switching concept may have a minor impact on the length of the epithelial attachment (0.84 vs. 1.91 mm), while the connective tissue adaptation compartment remains relatively unaffected. Moreover, platform switching resulted in less resorption of the alveolar crest (0.58 mm).
在动物模型中验证口腔种植体的“平台转换”概念，以保持牙槽嵴骨水平。
五头小型猪每头接受三个种植体，种植体/基台之间的 0.25 毫米不匹配，种植体平齐（T(0)）、低于牙槽嵴 1 毫米（T(1)）和高于牙槽嵴 1 毫米（T(+1)），作为对照，一个传统修复的种植体置于骨水平。种植体无瓣微创植入下颌骨。植入后 4 个月，处死动物，获得未脱钙的块状切片，并进行组织学分析。
种植体周围骨吸收的平均值分别为 1.09 ± 0.59 毫米（对照）、0.51（± 0.27 毫米，T(0)）、0.50（± 0.46 毫米，T(+1)）和 1.30（± 0.21 毫米，T(-1)）。T(0)、T(-1)试验组与对照组之间存在统计学显著差异（P<0.05）。对照种植体的平均生物学宽度长度为 3.20 毫米（± 0.33），其中结缔组织适应腔为 1.29 毫米（± 0.53），上皮附着为 1.91 毫米（± 0.71）。T(0)、T(+1)和 T(-1)种植体的平均生物学宽度分别为 1.97 毫米（± 1.20）、2.70 毫米（± 1.36）和 2.84 毫米（± 0.90），其中结缔组织适应腔分别为 1.21 毫米（± 0.97）、1.21 毫米（± 0.65）和 1.50 毫米（± 0.70），上皮附着分别为 0.84 毫米（± 0.93）、1.66 毫米（± 0.88）和 1.35 毫米（± 0.44）。各构型之间的差异主要与上皮附着的长度有关。C 部位的上皮附着明显长于 T(0)（P=0.014）。然而，在其他配置之间没有发现差异。
如果将种植体置于牙槽嵴骨水平，平台转换概念可能对上皮附着长度（0.84 毫米与 1.91 毫米）的影响较小，而结缔组织适应腔相对不受影响。此外，平台转换导致牙槽嵴吸收减少（0.58 毫米）。
