Microbial aspects of failing osseointegrated dental implants in humans.

The subgingival microflora of 18 failing implants were examined for pathogenic periodontal microorganisms. Peptostreptococcus micros was recovered from 6 failing implants, Wolinella recta from 6, Fusobacterium species from 5, Candida albicans from 5, and Bacteroides intermedius from 4. Enteric rods or pseudomonads constituted a significant part of the microflora in 5 failing implants. Actinobacillus actinomycetemcomitans, nonpigmented Bacteroides species, Capnocytophage species, and staphylococci were detected in a few implant failures. The present study showed that a complex microflora comprising oral as well as primarily non oral organisms, and bacteria as well as yeasts, can be associated with failing implants. This great diversity in microbial composition and antimicrobial susceptibility among "peri-implantitis" isolates suggest that antimicrobial therapies for implant failures should not be implemented without a prior comprehensive microbiological analysis.