Relationship Between Radiographic Bone Loss and Salivary IL- 1β Levels in Peri-Implantitis

Purpose: Peri-implantitis is a progressive inflammatory condition characterized by peri- implant bone loss and clinical signs of inflammation. Traditional diagnostic methods, including clinical and radiographic evaluations, have limitations in detecting the disease in its early stages. Salivary biomarkers, including interleukin-1β (IL-1β), have been identified as potential non-invasive indicators for diagnosing peri-implantitis. This study aimed to investigate the relationship between salivary IL-1β levels, radiographic bone loss, and clinical peri-implant parameters. Materials and Methods: 60 patients enrolled in this cross-sectional study (24 peri-implant health [PIH] and 36 with peri-implantitis [PI]), accounting for a total of 152 implants. Clinical parameters, including peri-implant pocket depth (PIPD), modified plaque index (mPI), and bleeding on probing (BOP), were recorded. Periapical radiographs were obtained to assess peri-implant bone loss in mesial (PIBLm) and distal (PIBLd) aspects. Unstimulated whole saliva samples were analyzed for IL-1β expression using quantitative real-time polymerase chain reaction (PCR). The correlations between IL-1β expression levels in saliva and peri-implant clinical and radiographic findings were analyzed using Pearson's correlation coefficient. Results: IL-1β expression levels in saliva were significantly higher in the PI compared to PIH (p<0.001). A strong positive correlation was observed between IL-1β levels and peri-implant bone loss (PIBLm: r=0.515, p<0.01; PIBLd: r=0.535, p<0.01), as well as with clinical parameters including PIPD (r=0.59, p<0.01) and BOP (r=0.792, p<0.001). Conclusion: The significant correlation between salivary IL-1β levels and peri-implant disease parameters suggests its potential as a non-invasive biomarker for early peri- implantitis detection. Further large-scale studies with standardized methodologies are required to validate these findings and enhance diagnostic accuracy.