Single-cell analysis of peri-implant gingival tissue to assess implant biocompatibility and immune response.

The innate immune response, particularly the reaction of polymorphonuclear neutrophils (PMNs), is crucial in shaping the outcomes of chronic inflammation, fibrosis, or osseointegration following biomaterial implantation. Peri-implantitis or peri-mucositis, inflammatory conditions linked to dental implants, pose a significant threat to implant success. We developed a single-cell analysis approach using a murine model to assess the immune response to implant materials, offering a practical screening tool for potential dental implants. We performed bioinformatics analysis and established a peri-implant inflammation model by inserting two titanium implants into the maxillary region, to examine the immune response. Bioinformatics analysis revealed that titanium implants triggered a host immune response, primarily mediated by PMNs. In the in vivo experiments, we observed a rapid PMN-mediated response, with increased infiltration around the implants and on the implant surface by day 3. Remarkably, PMN attachment to the implants persisted for 7 days, resembling the immune profiles seen in human implant-mediated inflammation. Our findings indicate that persistent attachment of the short-living PMNs to titanium implants can serve as an indicator or traits of peri-implant inflammation. Therefore, analyzing gingival tissue at the single-cell level could be a useful tool for evaluating the biocompatibility of candidate dental implants.