Abstract

In order to evaluate a new surface of an abutment and its skin reactions when introducing the bone anchored hearing system a clinical investigation was performed. Ten intended subjects were scheduled to receive a hydroxyapatitecoated abutment, using the tissue preserving surgery as a 1 step performance. Only 7 implants were installed due to peri-implant infections. The length of the abutments varied among the patients from 10-12 mm. Appointments were planned 1 week after surgery, at 7 weeks - 3 months, 6 and 12 months after surgery. Skin reactions were graded according to the Holgers´ scale. Unusual severe skin reactions were noted after implantation with the hydroxyapatite abutments, from 1 week to 7 months post-implantation, many of them classified as Holgers´. Some of the implanted persons suffered from pain. Positive bacterial cultures were found in 3 patients all showing Staphylococcus aureus. Good stability of all fixtures was achieved. Only 2 patients used after 1 year the primary implant and abutment.

Keywords: Bone anchored hearing implants; Peri-implant reactions; Hydroxyapatite