Failure patterns of four osseointegrated oral implant systems.

The aim of this metanalysis was to investigate possible differences in failure patterns among four different osseointegrated oral implant systems. Only systems with a supposed scientific validation, based on long-term follow-up studies, were selected for this analysis, i.e. the Brånemark system, the Calcitek Integral system, the Interpore IMZ system and the Straumann ITI system. While several prospective reports could be found on the Brånemark system, only a few retrospective investigations concerning the ITI and the IMZ systems were available. No data on the Integral system could be employed. Despite these limitations, a substantial difference in failure patterns among various implant systems was observed. The Brånemark implants showed a higher incidence of early failures, though sharply decreasing over time. On the contrary, IMZ implant characterized by rougher surfaces displayed a lower incidence of early failures, but showed constant or increased failure rates over time. For the ITI implants, for example, a higher prevalence of late failures, attributable to chronic bacterial infection (peri-implantitis), was observed when compared to the Brånemark system. With the exception of the latter implant system, prospective long-term follow-up studies, using similar and well-defined success criteria, are needed for the others to confirm the current preliminary findings.