Dr. Amruta Joshi (Hannover, DE), Dr. Szymon Piotr Szafrański (Hannover, DE), Dr. Matthias Steglich (Hannover, DE), Prof. Dr. Ines Yang (Hannover, DE), Amy Seidel (Hannover, DE), Sophie Dieckow (Hannover, DE), Dr. Jasmin Grischke (Hannover, DE), Dr. Katharina Nikutta-Doll (Hannover, DE), Paula Schäfer-Dreyer (Hannover, DE), Dr. Matthias Preuße (Braunschweig, DE), Prof. Dr. Susanne Häußler (Braunschweig, DE), Prof. Dr. Meike Stiesch (Hannover, DE)
Abstract text (incl. figure legends and references)
Question- Biofilm-associated implant infections continue to be a major complication in dentistry that lead to tissue destruction around the implant and occasionally subsequent implant loss. Early diagnosis of these infections is not currently possible. Yet, at the advanced disease stage, pathogenic biofilms are highly resistant towards therapy. Therefore, it is crucial to understand how implant-associated biofilms develop and become pathogenic. The aim of the study was the identification of molecular mechanisms that define the clinical course and severity of peri-implant biofilm infections.
Methods- More than 150 implants were studied in longitudinal and cross-sectional settings. Initial biofilm development was analyzed using temporary implant abutments. Mature biofilms were characterized in health, mucositis and peri-implantitis. Biofilm structures were characterized using CLSM and SEM. Composition and activity of biofilms were revealed with full 16S rRNA gene amplicons sequencing and RNA sequencing, respectively. Mechanisms were studied using in vitro models.
Results- Structure, composition and activity of biofilms were patient specific. Diverse anaerobes were more abundant and active in peri-implantitis. Streptococci dominated biofilms in health and mucositis, except for the Neisseria-rich subgroup of mucositis. Peptide degradation and catabolism of amino acids were upregulated in peri-implantitis, while diverse anabolic processes were typical for two other diagnosis groups. Interspecies interactions were prevalent in biofilms and contributed to biofilm fitness and resistance.
Conclusions- The present study revealed developmental mechanisms in implant-associated biofilms. Discovered signatures of diseases play an important role in virulence of biofilms but need to be further validated in clinical studies. In future, highly predictive biomarkers can be used to provide personalized peri-implant therapy.