Salivary IL-1β and red complex bacteria as predictors of the inflammatory status in sub-peri-implant niches of subjects with peri-implant mucositis

Background and objectives Salivary biomarkers may enhance diagnostic sensitivity for peri-implant disease assessment. This study aimed to investigate the association of salivary periodontopathogen count and salivary interleukin-1beta (IL-1β) level with the peri-implant crevicular fluid IL-1β response at peri-implant mucositis (PM) sites among subjects with differing periodontal disease susceptibility. Materials and methods Eighty-seven partially edentulous subjects having at least one implant with peri-implant mucositis were included: 40 with history of chronic periodontitis (P) and 47 with no history of periodontitis (NP). Salivary IL-1β, peri-implant crevicular fluid (PICF) IL-1β, and salivary red complex pathogen counts were recorded. Subjects were scored according to a threshold salivary pathogen level of more than 5log (10) counts and assigned a "red complex score." Quartiles of salivary and PICF IL-1β levels were also scored. Area under receiver operating curve (AUC) was computed to predict the highest PICF IL-1β score using salivary biomarker as predictors and age-adjusted logistic regression performed for the significant predictors. Results In the NP group, red complex score (AUC = 0.758 P = 0.010) (odds ratio = 1.377) and salivary IL-1β (AUC = 0.708 P = 0.038) (odds ratio = 2.506) were significant predictors of highest PICF IL-1β quartile score. In the P group, no significant associations were noted. Conclusions Salivary biomarkers could distinguish the "high" pro-inflammatory responders at PM sites only in subjects without inherent periodontal disease susceptibility. Periodontal susceptibility may impact the immuno-inflammatory response in sub-peri-implant niches of those with peri-implant mucositis.