A longitudinal microbiological study on osseointegrated titanium implants in partially edentulous patients

The aim was to longitudinally follow the colonization of putative periodontal pathogens on titanium implants in partially edentulous patients. Nineteen individuals, who were partially edentulous and were on the waiting-list to be treated with titanium fixtures, were included in the study. They were treated for periodontal disease with oral hygiene instructions and supra- and subgingival debridement and were left for maintenance. Full-mouth recordings of each patient were performed at baseline, including attachment level and probing pocket depth. Bleeding was provoked and visible plaque were registered. Subgingival samples were taken for examination of Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans. Bridge connection was completed 1 month after abutment connection. The bone level was registered on radiographs. The patients were followed with clinical registrations and subgingival samples at 6, 12, 24 and 36 months. No significant changes in pocket depth, attachment level, bleeding on probing or plaque score occurred during the experimental period. The number of individuals positive at teeth and abutments for the various bacterial species reached approximately similar levels at 6 months. No significant changes over time were seen. Comparison between bone height, seen on radiographs, at abutments after 2, 12 and 36 months gave only 3 sites with bone loss of > 0.5 mm. All these sites were found in one patient and were accompanied by P. intermedia.