University thesis:
Dissertation, Universität Freiburg, 2024
Footnote:
Description:
Abstract: Peri-implantitis is a common disease affecting more than 20 % of all dental implants. The peri-implant crevicular fluid of healthy and peri-implantitis affected implants has not been systematically investigated on the proteome level. In the present study, the aim was to assess the peri-implant crevicular fluid composition in an untargeted approach using mass-spectrometry-based proteomics with data independent acquisition.<br>Peri-implantitis was defined according to the current German S3-guideline. Crevicular fluid was collected from patients with at least one diseased implant using sterile paper strips. For sample processing, a unique protocol was developed. Liquid chromatography tandem mass spectrometry was applied, and data was processed using DiaNN, quantifying both human and bacterial proteins. Furthermore, DiaNN was used for detection of semi-specific peptides. <br>Overall, 14 patients with 38 samples were enrolled in this study. 2332 unique human and 334 bacterial proteins were identified across all samples. Linear models for microarray analysis revealed no significantly altered human proteins between healthy implants and teeth. For peri-implantitis vs. healthy implants, 59 human proteins were found upregulated and 31 downregulated in disease with statistical significance. Gene Ontology analysis revealed several immunological and inflammatory pathways to be upregulated in peri-implantitis. Semi-specific peptides were found in higher concentration in case of peri-implantitis. <br>This study was the first to apply mass-spectrometry based proteomics on crevicular fluid of peri-implantitis and healthy implants, also demonstrating how mass-spectrometry can aid for detection of bacterial proteins. The crevicular fluid of peri-implantitis exhibits an inflammatory profile, characterized by increased proteolytic activity