Microbiota and clinical outcomes of implant-supported full-mandible dentures on patients with a history of periodontitis: A 5-year prospective cohort study.

Purpose: To characterize the microbiota of implant-supported full-mandible dentures and its correlation to clinical outcomes for up to 5 years after implant loading in patients with a history of periodontal disease.

Materials and methods: Twelve individuals with a history of periodontitis (Stage IV and Grade B) received five immediate implants and a fixed complete-arch mandibular prosthesis. Microbiological (total counts, microbial profile, and diversity) and clinical outcomes (probing depth, bleeding on probing, and bone resorption) were assessed before tooth extraction and at 4 and 5 years postloading. Thirty-five microbial species were detected and quantified by DNA checkerboard analysis.

Results: The microbiota significantly changed after 5 years of implant loading, with an increase in the abundance of periodontal pathogens and microbial diversity over time. The biofilm microbial profile and genome counts of implants were substantially different from the ones found in the remaining teeth at baseline, but no correlations between microbial taxa/counts and clinical outcomes were observed.

Conclusion: The microbiota of dental implants was found to be different from the remaining teeth in patients with a history of periodontitis. Significant microbial shifts occurred in the microbiota of implants after 5 years of function; nonetheless, the microbiological changes did not impact clinical outcomes, which were consistent with health throughout the follow-up period.