Findings in scanning electron microscopy in titanium ossicular replacementprostheses.

Background: Titanium as a biomaterial in ossicular replacement has widely s pread within the last couple of years. Methods: 23 prostheses (12 PORPs, pa rtial ossicular replacement prostheses and 11 TORPs total ossicular replace ment prostheses) removed during revision surgery were studied using scannin g electron microscopy. The average implantation time was 8 (range 3-15) mon ths,The specimens were investigated regarding tissue growth, epithelializat ion, inflammation and cellular signs of rejection. Results: Only few prosth eses were totally covered by connective tissue or epithelium due to technic al problems in removing the implant and the covering tissue as one specimen . But this offered the possibility to study the interface at the edges wher e the tissue was torn off, The connective tissue looked unremarkable. Polyg onal squamous epithelium was detected on several implants, Respiratory epit helium with ciliated cells and mucus producing goblet cells was seen in two specimens. In cases of cholesteatoma or protrusion the explanted prosthese s showed typical rosette-like formation of hornifying squamous epithelium. According to underlying disease a lymphocytic infiltration could be seen, T here were no cellular signs of incompatibility noticed neither macrophages nor foreign body giant cells, Conclusions: From these investigations titani um seems to be a favorable biomaterial for ossicular replacement with good acceptance also in an implantation site showing chronic inflammation.