Surface analysis of titanium maxillofacial plates and screws retrieved from patients.

This investigation is a controlled human plate-retrieval study. The surface appearances and elemental composition of 50 titanium maxillofacial plates and associated screws retrieved from 39 patients were compared with a control sample of unused plates and screws using stereomicroscopy, scanning electron microscopy and energy dispersive X-ray analysis. There were two surface finishes, either anodized or non-anodized. Surface contamination was detected on both retrieved and control plates consisting of aluminium and silica and was more commonly present on non-anodized specimens. Manufacturing defects comprising rough metal edges and protuberances were identified on the unused controls and surgical damage was evident on the retrieved specimens. There were no signs of corrosion or surface deterioration on the retrieved plates and screws which had been in the tissues for between 1 month and 13 years. There was no evidence from this study to support the routine removal of titanium maxillofacial miniplates plates due to corrosion up to a period of 13 years.