Clinical Device-Related Article Histomorphologic Analysis of 30 Plateau Root Form Implants Retrieved After 8 to 13 Years in Function. A Human Retrieval Study

The objective of this study was to evaluate the morphology and integration status of 30 human retrieved plateau root form implants. Thirty plateau design root form implants that were in function from 8 to 13 years were retrieved from patients due to prosthetic reasons. Following surgical removal, the samples remained in 10% buffered formaline for 7 days. Bone morphology was evaluated by transmitted and polarized light microscopy, and bone-to-implant contact (BIC) histomorphometric assessment was determined through computer software. Irrespective of time in vivo, lamellar bone was observed in close contact with the implant surface and between plateaus. BIC ranged from similar to 20 to similar to 80%. Polarized light microscopy showed a highly directional osteonic morphology between plateaus for most implants. A haversian-like microstructure running perpendicular to and along with the implants' long axis (between plateaus) was observed in regions of cortical and trabecular bone, revealing a unique bone microstructural evolution over time around functionally loaded plateau root form implants. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 91B: 975-979, 2009