A clinical retrospective evaluation of FA/HA coated (Biocomp) dental implants. Results after 1 year.

In this retrospective clinical evaluation, the performance of loaded titanium implants with a bilayer bioactive surface coating of the relatively reactive hydroxylapatite (HA, outer layer) and the more stable fluorapatite (FA, inner layer) was evaluated. 98 consecutive patients were included in the study for a total of 354 implants, loaded by overdentures, fixed partial dentures and single tooth replacements. Statistical analyses revealed a cumulative probability of implant survival on a per patient basis of 94.5% (s.e. 2.7%), one year after implant installation. On implants that were lost parts of the bilayer FA/HA coating had vanished as a result of primary or secondary infection and subsequently epithelial down growth. Most complications were associated with implants placed in the maxilla. Periotest values (PTV) were generally high, indicating adequate osseointegration. The PTV's were statistically significantly less favorable in implants placed in the maxilla. The most favorable PTV's and gingival index scores were found around implants servicing overdentures. Marginal bone loss averaged approximately 2mm during the observation period. The amount of marginal bone loss corresponded with the distance from the neck of the implant to the first thread of the implant's cervical screw-section. It is concluded that, during the relatively short observation period, the FA/HA coated implants function adequately. However, in the absence of a direct implant-to-bone contact preceding implant loss, part of the FA/HA coating on the titanium implants generally dissolves.