Peri-Implantitis (Infective Process- Bacterial Origin)
Bacterial invasion of the peri-implant soft tissue results in its inflammation followed by rapid bone loss. Peri-Implantitis as defined by Meffert is the progressive loss of peri implant bone as well as soft tissue inflammatory changes.
It has been shown that Gram Negative rods including Bacteroides and Fusobacterium sp. are consistent with failing implants. Spirochaetes and motile rods with a predominance of Peptosteptococcus micros, Actinobacillus actinomycetemcomitans, Prevotella intermedia and Porphyromonas gingivalis have been shown to be associated with failing implants.
The similarity in clinical signs and the bacterial microflora suggest a similarity between failing implants and periodontitis. The role of bacterial infection in the aetiology of dental implant failure has been clearly documented, therefore in a partially edentulous situation, complete periodontal therapy should be completed prior to implant placement as the similarity of the microflora indicates a probable bacterial migration into the implant site.