Potential Risk Factors for Oral Implant Failures

Objective: In order to identify possible risk factors for implant failures, statistical significances have been evaluated regarding patient-, implant- and treatment characteristics and combinations of these, respectively. Methods: Out of a database, including four prospective multi-centre studies on dental implant treatment (Brånemark system®, Nobel Biocare AB), all with different treatment protocols, a research database with one randomly selected implant per patient was created. This database consisted of 487 patients. During 5-years of follow-up, 36 implants failed, while 371 were regarded as successful. The remaining 80 implants were withdrawn. Individual variables such as treated jaw, patient age and gender, responsible clinic, jaw-bone quality and shape, implant length, treatment protocol, number of implants per construction, respectively, were evaluated by chi-squared tests and post hoc as well as multilevel analyses regarding their possible influence on the risk for implant losses. Results: Significant risks for failures were identified in relation to the variables: treated jaw, jawbone quality and shape, implant length and treatment protocol, respectively. However, patient age and gender, responsible clinics and number of implants supporting the construction did not show the same risks. Conclusion: The results, therefore, indicated that jaw related factors seemed to be more important than general patient and treatment characteristics, when it comes to predict oral implant failures.